The can_get_echo_skb() function returns the number of received bytes to
be used for netdev statistics. In the case of RTR frames we get a valid
(potential non-zero) data length value which has to be passed for further
operations. But on the wire RTR frames have no payload length. Therefore
the value to be used in the statistics has to be zero for RTR frames.
Reported-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/r/20201020064443.80164-1-socketcan@hartkopp.net Fixes: cf5046b309b3 ("can: dev: let can_get_echo_skb() return dlc of CAN frame") Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
If a driver calls can_get_echo_skb() during a hardware IRQ (which is often, but
not always, the case), the 'WARN_ON(in_irq)' in
net/core/skbuff.c#skb_release_head_state() might be triggered, under network
congestion circumstances, together with the potential risk of a NULL pointer
dereference.
The root cause of this issue is the call to kfree_skb() instead of
dev_kfree_skb_irq() in net/core/dev.c#enqueue_to_backlog().
This patch prevents the skb to be freed within the call to netif_rx() by
incrementing its reference count with skb_get(). The skb is finally freed by
one of the in-irq-context safe functions: dev_consume_skb_any() or
dev_kfree_skb_any(). The "any" version is used because some drivers might call
can_get_echo_skb() in a normal context.
The reason for this issue to occur is that initially, in the core network
stack, loopback skb were not supposed to be received in hardware IRQ context.
The CAN stack is an exeption.
This bug was previously reported back in 2017 in [1] but the proposed patch
never got accepted.
While [1] directly modifies net/core/dev.c, we try to propose here a
smoother modification local to CAN network stack (the assumption
behind is that only CAN devices are affected by this issue).
A CAN driver, using the rx-offload infrastructure, is reading CAN frames
(usually in IRQ context) from the hardware and placing it into the rx-offload
queue to be delivered to the networking stack via NAPI.
In case the rx-offload queue is full, trying to add more skbs results in the
skbs being dropped using kfree_skb(). If done from hard-IRQ context this
results in the following warning:
[ 682.552693] ------------[ cut here ]------------
[ 682.557360] WARNING: CPU: 0 PID: 3057 at net/core/skbuff.c:650 skb_release_head_state+0x74/0x84
[ 682.566075] Modules linked in: can_raw can coda_vpu flexcan dw_hdmi_ahb_audio v4l2_jpeg imx_vdoa can_dev
[ 682.575597] CPU: 0 PID: 3057 Comm: cansend Tainted: G W 5.7.0+ #18
[ 682.583098] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[ 682.589657] [<c0112628>] (unwind_backtrace) from [<c010c1c4>] (show_stack+0x10/0x14)
[ 682.597423] [<c010c1c4>] (show_stack) from [<c06c481c>] (dump_stack+0xe0/0x114)
[ 682.604759] [<c06c481c>] (dump_stack) from [<c0128f10>] (__warn+0xc0/0x10c)
[ 682.611742] [<c0128f10>] (__warn) from [<c0129314>] (warn_slowpath_fmt+0x5c/0xc0)
[ 682.619248] [<c0129314>] (warn_slowpath_fmt) from [<c0b95dec>] (skb_release_head_state+0x74/0x84)
[ 682.628143] [<c0b95dec>] (skb_release_head_state) from [<c0b95e08>] (skb_release_all+0xc/0x24)
[ 682.636774] [<c0b95e08>] (skb_release_all) from [<c0b95eac>] (kfree_skb+0x74/0x1c8)
[ 682.644479] [<c0b95eac>] (kfree_skb) from [<bf001d1c>] (can_rx_offload_queue_sorted+0xe0/0xe8 [can_dev])
[ 682.654051] [<bf001d1c>] (can_rx_offload_queue_sorted [can_dev]) from [<bf001d6c>] (can_rx_offload_get_echo_skb+0x48/0x94 [can_dev])
[ 682.666007] [<bf001d6c>] (can_rx_offload_get_echo_skb [can_dev]) from [<bf01efe4>] (flexcan_irq+0x194/0x5dc [flexcan])
[ 682.676734] [<bf01efe4>] (flexcan_irq [flexcan]) from [<c019c1ec>] (__handle_irq_event_percpu+0x4c/0x3ec)
[ 682.686322] [<c019c1ec>] (__handle_irq_event_percpu) from [<c019c5b8>] (handle_irq_event_percpu+0x2c/0x88)
[ 682.695993] [<c019c5b8>] (handle_irq_event_percpu) from [<c019c64c>] (handle_irq_event+0x38/0x5c)
[ 682.704887] [<c019c64c>] (handle_irq_event) from [<c01a1058>] (handle_fasteoi_irq+0xc8/0x180)
[ 682.713432] [<c01a1058>] (handle_fasteoi_irq) from [<c019b2c0>] (generic_handle_irq+0x30/0x44)
[ 682.722063] [<c019b2c0>] (generic_handle_irq) from [<c019b8f8>] (__handle_domain_irq+0x64/0xdc)
[ 682.730783] [<c019b8f8>] (__handle_domain_irq) from [<c06df4a4>] (gic_handle_irq+0x48/0x9c)
[ 682.739158] [<c06df4a4>] (gic_handle_irq) from [<c0100b30>] (__irq_svc+0x70/0x98)
[ 682.746656] Exception stack(0xe80e9dd8 to 0xe80e9e20)
[ 682.751725] 9dc0: 00000001e80e8000
[ 682.759922] 9de0: e820cf8000000000ffffe00000000000eaf08fe400000000600d001300000000
[ 682.768117] 9e00: c1732e3cc16093a8e820d4c0e80e9e28c018a57cc018b870600d0013ffffffff
[ 682.776315] [<c0100b30>] (__irq_svc) from [<c018b870>] (lock_acquire+0x108/0x4e8)
[ 682.783821] [<c018b870>] (lock_acquire) from [<c0e938e4>] (down_write+0x48/0xa8)
[ 682.791242] [<c0e938e4>] (down_write) from [<c02818dc>] (unlink_file_vma+0x24/0x40)
[ 682.798922] [<c02818dc>] (unlink_file_vma) from [<c027a258>] (free_pgtables+0x34/0xb8)
[ 682.806858] [<c027a258>] (free_pgtables) from [<c02835a4>] (exit_mmap+0xe4/0x170)
[ 682.814361] [<c02835a4>] (exit_mmap) from [<c01248e0>] (mmput+0x5c/0x110)
[ 682.821171] [<c01248e0>] (mmput) from [<c012e910>] (do_exit+0x374/0xbe4)
[ 682.827892] [<c012e910>] (do_exit) from [<c0130888>] (do_group_exit+0x38/0xb4)
[ 682.835132] [<c0130888>] (do_group_exit) from [<c0130914>] (__wake_up_parent+0x0/0x14)
[ 682.843063] irq event stamp: 1936
[ 682.846399] hardirqs last enabled at (1935): [<c02938b0>] rmqueue+0xf4/0xc64
[ 682.853553] hardirqs last disabled at (1936): [<c0100b20>] __irq_svc+0x60/0x98
[ 682.860799] softirqs last enabled at (1878): [<bf04cdcc>] raw_release+0x108/0x1f0 [can_raw]
[ 682.869256] softirqs last disabled at (1876): [<c0b8f478>] release_sock+0x18/0x98
[ 682.876753] ---[ end trace 7bca4751ce44c444 ]---
This patch fixes the problem by replacing the kfree_skb() by
dev_kfree_skb_any(), as rx-offload might be called from threaded IRQ handlers
as well.
In ip_set_match_extensions(), for sets with counters, we take care of
updating counters themselves by calling ip_set_update_counter(), and of
checking if the given comparison and values match, by calling
ip_set_match_counter() if needed.
However, if a given comparison on counters doesn't match the configured
values, that doesn't mean the set entry itself isn't matching.
This fix restores the behaviour we had before commit 4750005a85f7
("netfilter: ipset: Fix "don't update counters" mode when counters used
at the matching"), without reintroducing the issue fixed there: back
then, mtype_data_match() first updated counters in any case, and then
took care of matching on counters.
Now, if the IPSET_FLAG_SKIP_COUNTER_UPDATE flag is set,
ip_set_update_counter() will anyway skip counter updates if desired.
The issue observed is illustrated by this reproducer:
ipset create c hash:ip counters
ipset add c 192.0.2.1
iptables -I INPUT -m set --match-set c src --bytes-gt 800 -j DROP
if we now send packets from 192.0.2.1, bytes and packets counters
for the entry as shown by 'ipset list' are always zero, and, no
matter how many bytes we send, the rule will never match, because
counters themselves are not updated.
Reported-by: Mithil Mhatre <mmhatre@redhat.com> Fixes: 4750005a85f7 ("netfilter: ipset: Fix "don't update counters" mode when counters used at the matching") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Make sure that we actually initialize xefi_discard when we're scheduling
a deferred free of an AGFL block. This was (eventually) found by the
UBSAN while I was banging on realtime rmap problems, but it exists in
the upstream codebase. While we're at it, rearrange the structure to
reduce the struct size from 64 to 56 bytes.
Fixes: fcb762f5de2e ("xfs: add bmapi nodiscard flag") Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
we found that the following race condition exists in
xfrm_alloc_userspi flow:
user thread state_hash_work thread
---- ----
xfrm_alloc_userspi()
__find_acq_core()
/*alloc new xfrm_state:x*/
xfrm_state_alloc()
/*schedule state_hash_work thread*/
xfrm_hash_grow_check() xfrm_hash_resize()
xfrm_alloc_spi /*hold lock*/
x->id.spi = htonl(spi) spin_lock_bh(&net->xfrm.xfrm_state_lock)
/*waiting lock release*/ xfrm_hash_transfer()
spin_lock_bh(&net->xfrm.xfrm_state_lock) /*add x into hlist:net->xfrm.state_byspi*/
hlist_add_head_rcu(&x->byspi)
spin_unlock_bh(&net->xfrm.xfrm_state_lock)
/*add x into hlist:net->xfrm.state_byspi 2 times*/
hlist_add_head_rcu(&x->byspi)
1. a new state x is alloced in xfrm_state_alloc() and added into the bydst hlist
in __find_acq_core() on the LHS;
2. on the RHS, state_hash_work thread travels the old bydst and tranfers every xfrm_state
(include x) into the new bydst hlist and new byspi hlist;
3. user thread on the LHS gets the lock and adds x into the new byspi hlist again.
So the same xfrm_state (x) is added into the same list_hash
(net->xfrm.state_byspi) 2 times that makes the list_hash become
an inifite loop.
To fix the race, x->id.spi = htonl(spi) in the xfrm_alloc_spi() is moved
to the back of spin_lock_bh, sothat state_hash_work thread no longer add x
which id.spi is zero into the hash_list.
It is not an error if the host requests to balloon down, but the VM
refuses to do so. Without this change a warning is logged in dmesg
every five minutes.
Fixes: b3bb97b8a49f3 ("Drivers: hv: balloon: Add logging for dynamic memory operations") Signed-off-by: Olaf Hering <olaf@aepfle.de> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201008071216.16554-1-olaf@aepfle.de Signed-off-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
All of these lockup reports have the call chain btrfs_clone_files() ->
btrfs_clone() in common. btrfs_clone_files() calls btrfs_clone() with
both source and destination extents locked and loops over the source
extent to create the clones.
Conditionally reschedule in the btrfs_clone() loop, to give some time back
to other processes.
CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
This happens because we are holding the chunk_mutex at the time of
adding in a new device. However we only need to hold the
device_list_mutex, as we're going to iterate over the fs_devices
devices. Move the sysfs init stuff outside of the chunk_mutex to get
rid of this lockdep splat.
CC: stable@vger.kernel.org # 4.4.x: f3cd2c58110dad14e: btrfs: sysfs, rename device_link add/remove functions CC: stable@vger.kernel.org # 4.4.x Reported-by: David Sterba <dsterba@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
An SG request may be partially completed (due to no available TRBs).
Don't reclaim extra TRBs and clear the needs_extra_trb flag until the
request is fully completed. Otherwise, the driver will reclaim the wrong
TRB.
Mounted NBD device can be resized, one use case is rbd-nbd.
Fix the issue by setting up default block size, then not touch it
in nbd_size_update() any more. This kind of usage is aligned with loop
which has same use case too.
Cc: stable@vger.kernel.org Fixes: c8a83a6b54d0 ("nbd: Use set_blocksize() to set device blocksize") Reported-by: lining <lining2020x@163.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Jan Kara <jack@suse.cz> Tested-by: lining <lining2020x@163.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
Undefined behaviour in ./include/linux/time64.h:127:27
signed integer overflow: 17179869187 * 1000000000 cannot be represented in type 'long long int'
Call Trace:
timespec64_to_ns include/linux/time64.h:127 [inline]
set_cpu_itimer+0x65c/0x880 kernel/time/itimer.c:180
do_setitimer+0x8e/0x740 kernel/time/itimer.c:245
__x64_sys_setitimer+0x14c/0x2c0 kernel/time/itimer.c:336
do_syscall_64+0xa1/0x540 arch/x86/entry/common.c:295
Commit bd40a175769d ("y2038: itimer: change implementation to timespec64")
replaced the original conversion which handled time clamping correctly with
timespec64_to_ns() which has no overflow protection.
Fix it in timespec64_to_ns() as this is not necessarily limited to the
usage in itimers.
[ tglx: Added comment and adjusted the fixes tag ]
Fixes: 361a3bf00582 ("time64: Add time64.h header and define struct timespec64") Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/1598952616-6416-1-git-send-email-prime.zeng@hisilicon.com Signed-off-by: Sasha Levin <sashal@kernel.org>
regulator_get_voltage_rdev() is called in regulator probe() when
applying machine constraints. The "fixed" commit exposed the problem
that non-bypassed regulators can forward the request to its parent
(like bypassed ones) supply. Return -EPROBE_DEFER when the supply
is expected but not resolved yet.
Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator") Cc: stable@vger.kernel.org Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Reported-by: Ondřej Jirman <megous@megous.com> Reported-by: Corentin Labbe <clabbe.montjoie@gmail.com> Tested-by: Ondřej Jirman <megous@megous.com> Link: https://lore.kernel.org/r/a9041d68b4d35e4a2dd71629c8a6422662acb5ee.1604351936.git.mirq-linux@rere.qmqm.pl Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Remove non-privileged user access to power data contained in
/sys/class/powercap/intel-rapl*/*/energy_uj
Non-privileged users currently have read access to power data and can
use this data to form a security attack. Some privileged
drivers/applications need read access to this data, but don't expose it
to non-privileged users.
For example, thermald uses this data to ensure that power management
works correctly. Thus removing non-privileged access is preferred over
completely disabling this power reporting capability with
CONFIG_INTEL_RAPL=n.
Fixes: 95677a9a3847 ("PowerCap: Fix mode for energy counter") Signed-off-by: Len Brown <len.brown@intel.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Espressobin boards have 3 ethernet ports and some of them got assigned more
then one MAC address. MAC addresses are stored in U-Boot environment.
Since commit a2c7023f7075c ("net: dsa: read mac address from DT for slave
device") kernel can use MAC addresses from DT for particular DSA port.
Currently Espressobin DTS file contains alias just for ethernet0.
This patch defines additional ethernet aliases in Espressobin DTS files, so
bootloader can fill correct MAC address for DSA switch ports if more MAC
addresses were specified.
DT alias ethernet1 is used for wan port, DT aliases ethernet2 and ethernet3
are used for lan ports for both Espressobin revisions (V5 and V7).
Fixes: 5253cb8c00a6f ("arm64: dts: marvell: espressobin: add ethernet alias") Cc: <stable@vger.kernel.org> # a2c7023f7075c: dsa: read mac address Signed-off-by: Pali Rohár <pali@kernel.org> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Andre Heider <a.heider@gmail.com> Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
[pali: Backported Espressobin rev V5 changes to 5.4 and 4.19 versions] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Guenter Roeck [Sun, 8 Nov 2020 00:31:24 +0000 (16:31 -0800)]
tools: perf: Fix build error in v4.19.y
perf may fail to build in v4.19.y with the following error.
util/evsel.c: In function ‘perf_evsel__exit’:
util/util.h:25:28: error:
passing argument 1 of ‘free’ discards ‘const’ qualifier from pointer target type
This is observed (at least) with gcc v6.5.0. The underlying problem is
the following statement.
zfree(&evsel->pmu_name);
evsel->pmu_name is decared 'const *'. zfree in turn is defined as
#define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
and thus passes the const * to free(). The problem is not seen
in the upstream kernel since zfree() has been rewritten there.
The problem has been introduced into v4.19.y with the backport of upstream
commit d4953f7ef1a2 (perf parse-events: Fix 3 use after frees found with
clang ASAN).
One possible fix of this problem would be to not declare pmu_name
as const. This patch chooses to typecast the parameter of zfree()
to void *, following the guidance from the upstream kernel which
does the same since commit 7f7c536f23e6a ("tools lib: Adopt
zalloc()/zfree() from tools/perf")
Fixes: a0100a363098 ("perf parse-events: Fix 3 use after frees found with clang ASAN") Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since the device is resumed from runtime-suspend in
__device_release_driver() anyway, it is better to do that before
looking for busy managed device links from it to consumers, because
if there are any, device_links_unbind_consumers() will be called
and it will cause the consumer devices' drivers to unbind, so the
consumer devices will be runtime-resumed. In turn, resuming each
consumer device will cause the supplier to be resumed and when the
runtime PM references from the given consumer to it are dropped, it
may be suspended. Then, the runtime-resume of the next consumer
will cause the supplier to resume again and so on.
Update the code accordingly.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Fixes: 9ed9895370ae ("driver core: Functional dependencies tracking support") Cc: All applicable <stable@vger.kernel.org> # All applicable Tested-by: Xiang Chen <chenxiang66@hisilicon.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The original commit was a preventive fix based on code-review and was
auto-picked for stable back-port (for better or worse).
It was OK for v5.3+ kernels, but turned up needing an implicit change 68e5c6f073bcf70 "(ARC: entry: EV_Trap expects r10 (vs. r9) to have
exception cause)" merged in v5.3 which itself was not backported.
So to summarize the stable backport of this patch for v5.2 and prior
kernels is busted and it won't boot.
The obvious solution is backport 68e5c6f073bcf70 but that is a pain as
it doesn't revert cleanly and each of affected kernels (so far v4.19,
v4.14, v4.9, v4.4) needs a slightly different massaged varaint.
So the easier fix is to simply revert the backport from 5.2 and prior.
The issue was not a big deal as it would cause strace to sporadically
not work correctly.
Waldemar Brodkorb first reported this when running ARC uClibc regressions
on latest stable kernels (with offending backport). Once he bisected it,
the analysis was trivial, so thx to him for this.
Currently stack unwinder is a while(1) loop which relies on the dwarf
unwinder to signal termination, which in turn relies on dwarf info to do
so. This in theory could cause an infinite loop if the dwarf info was
somehow messed up or the register contents were etc.
This fix thus detects the excessive looping and breaks the loop.
In Bugzilla #208257, Julien Humbert reports that a 32-GB Kingston
flash drive spontaneously disconnects and reconnects, over and over.
Testing revealed that disabling Link Power Management for the drive
fixed the problem.
This patch adds a quirk entry for that drive to turn off LPM permanently.
CC: Hans de Goede <jwrdegoede@fedoraproject.org> CC: <stable@vger.kernel.org> Reported-and-tested-by: Julien Humbert <julroy67@gmail.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20201102145821.GA1478741@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The write-URB busy flag was being cleared before the completion handler
was done with the URB, something which could lead to corrupt transfers
due to a racing write request if the URB is resubmitted.
Fixes: 507ca9bc0476 ("[PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used.") Cc: stable <stable@vger.kernel.org> # 2.6.13 Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the missing platform_driver_unregister() before return
from serial_txx9_init in the error handling case when failed
to register serial_txx9_pci_driver with macro ENABLE_SERIAL_TXX9_PCI
defined.
Mediatek 8250 port supports speed higher than uartclk / 16. If the baud
rates in both the new and the old termios setting are higher than
uartclk / 16, the WARN_ON in uart_get_baud_rate() will be triggered.
Passing NULL as the old termios so uart_get_baud_rate() will use
uartclk / 16 - 1 as the new baud rate which will be replaced by the
original baud rate later by tty_termios_encode_baud_rate() in
mtk8250_set_termios().
On Fri, Nov 06, 2020 at 10:30:08PM +0800, Minh Yuan wrote:
> We recently discovered a slab-out-of-bounds read in fbcon in the latest
> kernel ( v5.10-rc2 for now ). The root cause of this vulnerability is that
> "fbcon_do_set_font" did not handle "vc->vc_font.data" and
> "vc->vc_font.height" correctly, and the patch
> <https://lkml.org/lkml/2020/9/27/223> for VT_RESIZEX can't handle this
> issue.
>
> Specifically, we use KD_FONT_OP_SET to set a small font.data for tty6, and
> use KD_FONT_OP_SET again to set a large font.height for tty1. After that,
> we use KD_FONT_OP_COPY to assign tty6's vc_font.data to tty1's vc_font.data
> in "fbcon_do_set_font", while tty1 retains the original larger
> height. Obviously, this will cause an out-of-bounds read, because we can
> access a smaller vc_font.data with a larger vc_font.height.
Further there was only one user ever.
- Android's loadfont, busybox and console-tools only ever use OP_GET
and OP_SET
- fbset documentation only mentions the kernel cmdline font: option,
not anything else.
- systemd used OP_COPY before release 232 published in Nov 2016
Now unfortunately the crucial report seems to have gone down with
gmane, and the commit message doesn't say much. But the pull request
hints at OP_COPY being broken
https://github.com/systemd/systemd/pull/3651
So in other words, this never worked, and the only project which
foolishly every tried to use it, realized that rather quickly too.
Instead of trying to fix security issues here on dead code by adding
missing checks, fix the entire thing by removing the functionality.
Note that systemd code using the OP_COPY function ignored the return
value, so it doesn't matter what we're doing here really - just in
case a lone server somewhere happens to be extremely unlucky and
running an affected old version of systemd. The relevant code from
font_copy_to_all_vcs() in systemd was:
/* copy font from active VT, where the font was uploaded to */
cfo.op = KD_FONT_OP_COPY;
cfo.height = vcs.v_active-1; /* tty1 == index 0 */
(void) ioctl(vcfd, KDFONTOP, &cfo);
Note this just disables the ioctl, garbage collecting the now unused
callbacks is left for -next.
v2: Tetsuo found the old mail, which allowed me to find it on another
archive. Add the link too.
During __vsock_create() CAP_NET_ADMIN is used to determine if the
vsock_sock->trusted should be set to true. This value is used later
for determing if a remote connection should be allowed to connect
to a restricted VM. Unfortunately, if the caller doesn't have
CAP_NET_ADMIN, an audit message such as an selinux denial is
generated even if the caller does not want a trusted socket.
Logging errors on success is confusing. To avoid this, switch the
capable(CAP_NET_ADMIN) check to the noaudit version.
Reported-by: Roman Kiryanov <rkir@google.com>
https://android-review.googlesource.com/c/device/generic/goldfish/+/1468545/ Signed-off-by: Jeff Vander Stoep <jeffv@google.com> Reviewed-by: James Morris <jamorris@linux.microsoft.com> Link: https://lore.kernel.org/r/20201023143757.377574-1-jeffv@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
The current scanning mechanism is supposed to fall back to a synchronous
host scan if an asynchronous scan is in progress. However, this rule isn't
strictly respected, scsi_prep_async_scan() doesn't hold scan_mutex when
checking shost->async_scan. When scsi_scan_host() is called concurrently,
two async scans on same host can be started and a hang in do_scan_async()
is observed.
Fixes this issue by checking & setting shost->async_scan atomically with
shost->scan_mutex.
Link: https://lore.kernel.org/r/20201010032539.426615-1-ming.lei@redhat.com Cc: Christoph Hellwig <hch@lst.de> Cc: Ewan D. Milne <emilne@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Lee Duncan <lduncan@suse.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Similarly to commit 457e490f2b741 ("blkcg: allocate struct blkcg_gq
outside request queue spinlock"), blkg_create can also trigger
occasional -ENOMEM failures at the radix insertion because any
allocation inside blkg_create has to be non-blocking, making it more
likely to fail. This causes trouble for userspace tools trying to
configure io weights who need to deal with this condition.
This patch reduces the occurrence of -ENOMEMs on this path by preloading
the radix tree element on a GFP_KERNEL context, such that we guarantee
the later non-blocking insertion won't fail.
A similar solution exists in blkcg_init_queue for the same situation.
The reserved-memory overlap detection code fails to detect overlaps if
either of the regions starts at address 0x0. The code explicitly checks
for and ignores such regions, apparently in order to ignore dynamically
allocated regions which have an address of 0x0 at this point. These
dynamically allocated regions also have a size of 0x0 at this point, so
fix this by removing the check and sorting the dynamically allocated
regions ahead of any static regions at address 0x0.
For example, there are two overlaps in this case but they are not
currently reported:
kexec_file_load() currently reuses the old boot_params.screen_info,
but if drivers have change the hardware state, boot_param.screen_info
could contain invalid info.
For example, the video type might be no longer VGA, or the frame buffer
address might be changed. If the kexec kernel keeps using the old screen_info,
kexec'ed kernel may attempt to write to an invalid framebuffer
memory region.
There are two screen_info instances globally available, boot_params.screen_info
and screen_info. Later one is a copy, and is updated by drivers.
Gratian managed to trigger the BUG_ON(!newowner) in fixup_pi_state_owner().
This is one possible chain of events leading to this:
Task Prio Operation
T1 120 lock(F)
T2 120 lock(F) -> blocks (top waiter)
T3 50 (RT) lock(F) -> boosts T1 and blocks (new top waiter)
XX timeout/ -> wakes T2
signal
T1 50 unlock(F) -> wakes T3 (rtmutex->owner == NULL, waiter bit is set)
T2 120 cleanup -> try_to_take_mutex() fails because T3 is the top waiter
and the lower priority T2 cannot steal the lock.
-> fixup_pi_state_owner() sees newowner == NULL -> BUG_ON()
The comment states that this is invalid and rt_mutex_real_owner() must
return a non NULL owner when the trylock failed, but in case of a queued
and woken up waiter rt_mutex_real_owner() == NULL is a valid transient
state. The higher priority waiter has simply not yet managed to take over
the rtmutex.
The BUG_ON() is therefore wrong and this is just another retry condition in
fixup_pi_state_owner().
Drop the locks, so that T3 can make progress, and then try the fixup again.
Gratian provided a great analysis, traces and a reproducer. The analysis is
to the point, but it confused the hell out of that tglx dude who had to
page in all the futex horrors again. Condensed version is above.
The nesting count of trace_printk allows for 4 levels of nesting. The
nesting counter starts at zero and is incremented before being used to
retrieve the current context's buffer. But the index to the buffer uses the
nesting counter after it was incremented, and not its original number,
which in needs to do.
When an interrupt or NMI comes in and switches the context, there's a delay
from when the preempt_count() shows the update. As the preempt_count() is
used to detect recursion having each context have its own bit get set when
tracing starts, and if that bit is already set, it is considered a recursion
and the function exits. But if this happens in that section where context
has changed but preempt_count() has not been updated, this will be
incorrectly flagged as a recursion.
To handle this case, create another bit call TRANSITION and test it if the
current context bit is already set. Flag the call as a recursion if the
TRANSITION bit is already set, and if not, set it and continue. The
TRANSITION bit will be cleared normally on the return of the function that
set it, or if the current context bit is clear, set it and clear the
TRANSITION bit to allow for another transition between the current context
and an even higher one.
The code that checks recursion will work to only do the recursion check once
if there's nested checks. The top one will do the check, the other nested
checks will see recursion was already checked and return zero for its "bit".
On the return side, nothing will be done if the "bit" is zero.
The problem is that zero is returned for the "good" bit when in NMI context.
This will set the bit for NMIs making it look like *all* NMI tracing is
recursing, and prevent tracing of anything in NMI context!
The simple fix is to return "bit + 1" and subtract that bit on the end to
get the real bit.
The recursion protection of the ring buffer depends on preempt_count() to be
correct. But it is possible that the ring buffer gets called after an
interrupt comes in but before it updates the preempt_count(). This will
trigger a false positive in the recursion code.
Use the same trick from the ftrace function callback recursion code which
uses a "transition" bit that gets set, to allow for a single recursion for
to handle transitions between contexts.
Cc: stable@vger.kernel.org Fixes: 567cd4da54ff4 ("ring-buffer: User context bit recursion checking") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit fc0e38dae645 ("GFS2: Fix glock deallocation race") fixed a
sd_glock_disposal accounting bug by adding a missing atomic_dec
statement, but it failed to wake up sd_glock_wait when that decrement
causes sd_glock_disposal to reach zero. As a consequence,
gfs2_gl_hash_clear can now run into a 10-minute timeout instead of
being woken up. Add the missing wakeup.
The purpose of io_remap_pfn_range() is to map IO memory, such as a
memory mapped IO exposed through a PCI BAR. IO devices do not
understand encryption, so this memory must always be decrypted.
Automatically call pgprot_decrypted() as part of the generic
implementation.
This fixes a bug where enabling AMD SME causes subsystems, such as RDMA,
using io_remap_pfn_range() to expose BAR pages to user space to fail.
The CPU will encrypt access to those BAR pages instead of passing
unencrypted IO directly to the device.
Places not mapping IO should use remap_pfn_range().
Fixes: aca20d546214 ("x86/mm: Add support to make use of Secure Memory Encryption") Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: "Dave Young" <dyoung@redhat.com> Cc: Alexander Potapenko <glider@google.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Ingo Molnar <mingo@kernel.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Toshimitsu Kani <toshi.kani@hpe.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/0-v1-025d64bdf6c4+e-amd_sme_fix_jgg@nvidia.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When flags in queue_pages_pte_range don't have MPOL_MF_MOVE or
MPOL_MF_MOVE_ALL bits, code breaks and passing origin pte - 1 to
pte_unmap_unlock seems like not a good idea.
queue_pages_pte_range can run in MPOL_MF_MOVE_ALL mode which doesn't
migrate misplaced pages but returns with EIO when encountering such a
page. Since commit a7f40cfe3b7a ("mm: mempolicy: make mbind() return
-EIO when MPOL_MF_STRICT is specified") and early break on the first pte
in the range results in pte_unmap_unlock on an underflow pte. This can
lead to lockups later on when somebody tries to lock the pte resp.
page_table_lock again..
Fixes: a7f40cfe3b7a ("mm: mempolicy: make mbind() return -EIO when MPOL_MF_STRICT is specified") Signed-off-by: Shijie Luo <luoshijie1@huawei.com> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Feilong Lin <linfeilong@huawei.com> Cc: Shijie Luo <luoshijie1@huawei.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201019074853.50856-1-luoshijie1@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Zoom UAC-2 USB audio interface provides an async playback endpoint
("1 OUT (ASYNC)") and capture endpoint ("2 IN (ASYNC)"), both with
2-channel S32_LE in 44.1, 48, 88.2, 96, 176.4, or 192
kilosamples/s. The device provides explicit feedback to adjust the
host's playback rate, but the feedback appears unstable and biased
relative to the device's capture rate.
"alsaloop -t 1000" experiences playback underruns and tries to
resample the captured audio to match the varying playback
rate. Forcing the kernel to use implicit feedback appears to
produce more stable results. This causes the host to transmit one
playback sample for each capture sample received. (Zoom North America
has been notified of this change.)
Signed-off-by: Keith Winstein <keithw@cs.stanford.edu> Tested-by: Keith Winstein <keithw@cs.stanford.edu> Cc: <stable@vger.kernel.org> BugLink: https://lore.kernel.org/r/20201027071841.GA164525@trolley.csail.mit.edu Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 6735b4632def ("Fonts: Support FONT_EXTRA_WORDS macros for built-in
fonts") introduced the following error when building rpc_defconfig (only
this build appears to be affected):
`acorndata_8x8' referenced in section `.text' of arch/arm/boot/compressed/ll_char_wr.o:
defined in discarded section `.data' of arch/arm/boot/compressed/font.o
`acorndata_8x8' referenced in section `.data.rel.ro' of arch/arm/boot/compressed/font.o:
defined in discarded section `.data' of arch/arm/boot/compressed/font.o
make[3]: *** [/scratch/linux/arch/arm/boot/compressed/Makefile:191: arch/arm/boot/compressed/vmlinux] Error 1
make[2]: *** [/scratch/linux/arch/arm/boot/Makefile:61: arch/arm/boot/compressed/vmlinux] Error 2
make[1]: *** [/scratch/linux/arch/arm/Makefile:317: zImage] Error 2
The .data section is discarded at link time. Reinstating acorndata_8x8 as
const ensures it is still available after linking. Do the same for the
other 12 built-in fonts as well, for consistency purposes.
Cc: <stable@vger.kernel.org> Cc: Russell King <linux@armlinux.org.uk> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Fixes: 6735b4632def ("Fonts: Support FONT_EXTRA_WORDS macros for built-in fonts") Signed-off-by: Lee Jones <lee.jones@linaro.org> Co-developed-by: Peilin Ye <yepeilin.cs@gmail.com> Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20201102183242.2031659-1-yepeilin.cs@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Btrfs-progs already have a comprehensive type checker, to ensure there
is only 0 (SINGLE profile) or 1 (DUP/RAID0/1/5/6/10) bit set for chunk
profile bits.
Do the same work for kernel.
Reported-by: Yoon Jungyeon <jungyeon@gatech.edu> Link: https://bugzilla.kernel.org/show_bug.cgi?id=202765 Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
for ((i = 0; i < 4096; i++)); do
btrfs dev add -f $dev2 $mnt || _fail
btrfs dev del $dev1 $mnt || _fail
dev_tmp=$dev1
dev1=$dev2
dev2=$dev_tmp
done
[CAUSE]
Tree-checker uses BTRFS_MAX_DEVS() and BTRFS_MAX_DEVS_SYS_CHUNK() as
upper limit for devid. But we can have devid holes just like above
script.
So the check for devid is incorrect and could cause false alert.
[FIX]
Just remove the whole devid check. We don't have any hard requirement
for devid assignment.
Furthermore, even devid could get corrupted by a bitflip, we still have
dev extents verification at mount time, so corrupted data won't sneak
in.
This fixes fstests btrfs/194.
Reported-by: Anand Jain <anand.jain@oracle.com> Fixes: ab4ba2e13346 ("btrfs: tree-checker: Verify dev item") CC: stable@vger.kernel.org # 5.2+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.19: adjust context] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since we have btrfs_check_chunk_valid() in tree-checker, let's do
chunk item verification in tree-checker too.
Since the tree-checker is run at endio time, if one chunk leaf fails
chunk verification, we can still retry the other copy, making btrfs more
robust to fuzzed image as we may still get a good chunk item.
Also since we have done chunk verification in tree block read time, skip
the btrfs_check_chunk_valid() call in read_one_chunk() if we're reading
chunk items from leaf.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Cherry-picked for 4.19 to ease backporting later fixes] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
And for certain error message, also output expected value.
The error message levels are changed from error to critical.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Cherry-picked for 4.19 to ease backporting later fixes] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
By function, chunk item verification is more suitable to be done inside
tree-checker.
So move btrfs_check_chunk_valid() to tree-checker.c and export it.
And since it's now moved to tree-checker, also add a better comment for
what this function is doing.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Cherry-picked for 4.19 to ease backporting later fixes] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Note that leaf 29421568 doesn't have its backref in the extent tree.
Thus extent allocator can re-allocate leaf 29421568 for other trees.
In short, the bug is caused by:
- Existing tree block gets allocated to log tree
This got its generation bumped.
- Log tree balance cleaned dirty bit of offending tree block
It will not be written back to disk, thus no WRITTEN flag.
- Original owner of the tree block gets COWed
Since the tree block has higher transid, no WRITTEN flag, it's reused,
and not traced by transaction::dirty_pages.
- Transaction aborted
Tree blocks get cleaned according to transaction::dirty_pages. But the
offending tree block is not recorded at all.
- Filesystem unmount
All pages are assumed to be are clean, destroying all workqueue, then
call iput(btree_inode).
But offending tree block is still dirty, which triggers writeback, and
causes use-after-free bug.
The detailed sequence looks like this:
- Initial status
eb: 29421568, header=WRITTEN bflags_dirty=0, page_dirty=0, gen=8,
not traced by any dirty extent_iot_tree.
- New tree block is allocated
Since there is no backref for 29421568, it's re-allocated as new tree
block.
Keep in mind that tree block 29421568 is still referred by extent
tree.
- Tree block 29421568 is filled for log tree
eb: 29421568, header=0 bflags_dirty=1, page_dirty=1, gen=9 << (gen bumped)
traced by btrfs_root::dirty_log_pages
- Some log tree operations
Since the fs is using node size 4096, the log tree can easily go a
level higher.
- Log tree needs balance
Tree block 29421568 gets all its content pushed to right, thus now
it is empty, and we don't need it.
btrfs_clean_tree_block() from __push_leaf_right() get called.
eb: 29421568, header=0 bflags_dirty=0, page_dirty=0, gen=9
traced by btrfs_root::dirty_log_pages
- Log tree write back
btree_write_cache_pages() goes through dirty pages ranges, but since
page of tree block 29421568 gets cleaned already, it's not written
back to disk. Thus it doesn't have WRITTEN bit set.
But ranges in dirty_log_pages are cleared.
eb: 29421568, header=0 bflags_dirty=0, page_dirty=0, gen=9
not traced by any dirty extent_iot_tree.
- Extent tree update when committing transaction
Since tree block 29421568 has transid equal to running trans, and has
no WRITTEN bit, should_cow_block() will use it directly without adding
it to btrfs_transaction::dirty_pages.
eb: 29421568, header=0 bflags_dirty=1, page_dirty=1, gen=9
not traced by any dirty extent_iot_tree.
At this stage, we're doomed. We have a dirty eb not tracked by any
extent io tree.
- Transaction gets aborted due to corrupted extent tree
Btrfs cleans up dirty pages according to transaction::dirty_pages and
btrfs_root::dirty_log_pages.
But since tree block 29421568 is not tracked by neither of them, it's
still dirty.
eb: 29421568, header=0 bflags_dirty=1, page_dirty=1, gen=9
not traced by any dirty extent_iot_tree.
- Filesystem unmount
Since all cleanup is assumed to be done, all workqueus are destroyed.
Then iput(btree_inode) is called, expecting no dirty pages.
But tree 29421568 is still dirty, thus triggering writeback.
Since all workqueues are already freed, we cause use-after-free.
This shows us that, log tree blocks + bad extent tree can cause wild
dirty pages.
[FIX]
To fix the problem, don't submit any btree write bio if the filesytem
has any error. This is the last safe net, just in case other cleanup
haven't caught catch it.
Link: https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19377 CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.19: fs_info variable already exists in
btree_write_cache_pages()] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The lock_extent_buffer_io() returns 1 to the caller to tell it everything
went fine and the callers needs to start writeback for the extent buffer
(submit a bio, etc), 0 to tell the caller everything went fine but it does
not need to start writeback for the extent buffer, and a negative value if
some error happened.
When it's about to return 1 it tries to lock all pages, and if a try lock
on a page fails, and we didn't flush any existing bio in our "epd", it
calls flush_write_bio(epd) and overwrites the return value of 1 to 0 or
an error. The page might have been locked elsewhere, not with the goal
of starting writeback of the extent buffer, and even by some code other
than btrfs, like page migration for example, so it does not mean the
writeback of the extent buffer was already started by some other task,
so returning a 0 tells the caller (btree_write_cache_pages()) to not
start writeback for the extent buffer. Note that epd might currently have
either no bio, so flush_write_bio() returns 0 (success) or it might have
a bio for another extent buffer with a lower index (logical address).
Since we return 0 with the EXTENT_BUFFER_WRITEBACK bit set on the
extent buffer and writeback is never started for the extent buffer,
future attempts to writeback the extent buffer will hang forever waiting
on that bit to be cleared, since it can only be cleared after writeback
completes. Such hang is reported with a trace like the following:
So fix this by not overwriting the return value (ret) with the result
from flush_write_bio(). We also need to clear the EXTENT_BUFFER_WRITEBACK
bit in case flush_write_bio() returns an error, otherwise it will hang
any future attempts to writeback the extent buffer, and undo all work
done before (set back EXTENT_BUFFER_DIRTY, etc).
This is a regression introduced in the 5.2 kernel.
This function needs some extra checks on locked pages and eb. For error
handling we need to unlock locked pages and the eb.
There is a rare >0 return value branch, where all pages get locked
while write bio is not flushed.
Thankfully it's handled by the only caller, btree_write_cache_pages(),
as later write_one_eb() call will trigger submit_one_bio(). So there
shouldn't be any problem.
Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In btree_write_cache_pages(), we can only get @ret <= 0.
Add an ASSERT() for it just in case.
Then instead of submitting the write bio even we got some error, check
the return value first.
If we have already hit some error, just clean up the corrupted or
half-baked bio, and return error.
If there is no error so far, then call flush_write_bio() and return the
result.
Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since now flush_write_bio() could return error, kill the BUG_ON() first.
Then don't call flush_write_bio() unconditionally, instead we check the
return value from __extent_writepage() first.
If __extent_writepage() fails, we do cleanup, and return error without
submitting the possible corrupted or half-baked bio.
If __extent_writepage() successes, then we call flush_write_bio() and
return the result.
Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There exists a deadlock with range_cyclic that has existed forever. If
we loop around with a bio already built we could deadlock with a writer
who has the page locked that we're attempting to write but is waiting on
a page in our bio to be written out. The task traces are as follows
I used drgn to find the respective pages we were stuck on
page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901
page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874
As you can see the kworker is waiting for bit 0 (PG_locked) on index
7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index
8148. aio-dio-invalid has 7680, and the kworker epd looks like the
following
crash> struct extent_page_data ffffc900297bbbb0
struct extent_page_data {
bio = 0xffff889f747ed830,
tree = 0xffff889eed6ba448,
extent_locked = 0,
sync_io = 0
}
Probably worth mentioning as well that it waits for writeback of the
page to complete while holding a lock on it (at prepare_pages()).
Using drgn I walked the bio pages looking for page
0xffffea00fbfc7500 which is the one we're waiting for writeback on
bio = Object(prog, 'struct bio', address=0xffff889f747ed830)
for i in range(0, bio.bi_vcnt.value_()):
bv = bio.bi_io_vec[i]
if bv.bv_page.value_() == 0xffffea00fbfc7500:
print("FOUND IT")
which validated what I suspected.
The fix for this is simple, flush the epd before we loop back around to
the beginning of the file during writeout.
Fixes: b293f02e1423 ("Btrfs: Add writepages support") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Ben Hutchings [Mon, 12 Oct 2020 22:18:11 +0000 (23:18 +0100)]
Revert "btrfs: flush write bio if we loop in extent_write_cache_pages"
This reverts commit 860473714cbe7fbedcf92bfe3eb6d69fae8c74ff. That
has an incorrect upstream commit reference, and was modified in a way
that conflicts with some older fixes. We can cleanly cherry-pick the
upstream commit *after* those fixes.
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We have a BUG_ON() in flush_write_bio() to handle the return value of
submit_one_bio().
Move the BUG_ON() one level up to all its callers.
This patch will introduce temporary variable, @flush_ret to keep code
change minimal in this patch. That variable will be cleaned up when
enhancing the error handling later.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Cherry-picked for 4.19 to ease backporting later fixes] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is no need to forward declare flush_write_bio(), as it only
depends on submit_one_bio(). Both of them are pretty small, just move
them to kill the forward declaration.
Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Cherry-picked for 4.19 to ease backporting later fixes] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On commit 6ac93117ab00 ("blktrace: use existing disk debugfs directory")
merged on v4.12 Omar fixed the original blktrace code for request-based
drivers (multiqueue). This however left in place a possible crash, if you
happen to abuse blktrace while racing to remove / add a device.
We used to use asynchronous removal of the request_queue, and with that
the issue was easier to reproduce. Now that we have reverted to
synchronous removal of the request_queue, the issue is still possible to
reproduce, its however just a bit more difficult.
We essentially run two instances of break-blktrace which add/remove
a loop device, and setup a blktrace and just never tear the blktrace
down. We do this twice in parallel. This is easily reproduced with the
script run_0004.sh from break-blktrace [0].
We can end up with two types of panics each reflecting where we
race, one a failed blktrace setup:
debugfs: Directory 'loop0' with parent 'block' already present
This crash happens because of how blktrace uses the debugfs directory
where it places its files. Upon init we always create the same directory
which would be needed by blktrace but we only do this for make_request
drivers (multiqueue) block drivers. When you race a removal of these
devices with a blktrace setup you end up in a situation where the
make_request recursive debugfs removal will sweep away the blktrace
files and then later blktrace will also try to remove individual
dentries which are already NULL. The inverse is also possible and hence
the two types of use after frees.
We don't create the block debugfs directory on init for these types of
block devices:
* request-based block driver block devices
* every possible partition
* scsi-generic
And so, this race should in theory only be possible with make_request
drivers.
We can fix the UAF by simply re-using the debugfs directory for
make_request drivers (multiqueue) and only creating the ephemeral
directory for the other type of block devices. The new clarifications
on relying on the q->blk_trace_mutex *and* also checking for q->blk_trace
*prior* to processing a blktrace ensures the debugfs directories are
only created if no possible directory name clashes are possible.
This goes tested with:
o nvme partitions
o ISCSI with tgt, and blktracing against scsi-generic with:
o block
o tape
o cdrom
o media changer
o blktests
This patch is part of the work which disputes the severity of
CVE-2019-19770 which shows this issue is not a core debugfs issue, but
a misuse of debugfs within blktace.
Fixes: 6ac93117ab00 ("blktrace: use existing disk debugfs directory") Reported-by: syzbot+603294af2d01acfdd6da@syzkaller.appspotmail.com Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Omar Sandoval <osandov@fb.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Nicolai Stange <nstange@suse.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: yu kuai <yukuai3@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
[bwh: Backported to 4.19: open-code queue_is_mq()] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 978aa0474115 ("sctp: fix some type cast warnings introduced since
very beginning")' broke err reading from sctp_arg, because it reads the
value as 32-bit integer, although the value is stored as 16-bit integer.
Later this value is passed to the userspace in 16-bit variable, thus the
user always gets 0 on big-endian platforms. Fix it by reading the __u16
field of sctp_arg union, as reading err field would produce a sparse
warning.
Fixes: 978aa0474115 ("sctp: fix some type cast warnings introduced since very beginning") Signed-off-by: Petr Malat <oss@malat.biz> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Link: https://lore.kernel.org/r/20201030132633.7045-1-oss@malat.biz Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When PTP timestamping is enabled on Tx, the controller
inserts the Tx timestamp at the beginning of the frame
buffer, between SFD and the L2 frame header. This means
that the skb provided by the stack is required to have
enough headroom otherwise a new skb needs to be created
by the driver to accommodate the timestamp inserted by h/w.
Up until now the driver was relying on the second option,
using skb_realloc_headroom() to create a new skb to accommodate
PTP frames. Turns out that this method is not reliable, as
reallocation of skbs for PTP frames along with the required
overhead (skb_set_owner_w, consume_skb) is causing random
crashes in subsequent skb_*() calls, when multiple concurrent
TCP streams are run at the same time on the same device
(as seen in James' report).
Note that these crashes don't occur with a single TCP stream,
nor with multiple concurrent UDP streams, but only when multiple
TCP streams are run concurrently with the PTP packet flow
(doing skb reallocation).
This patch enforces the first method, by requesting enough
headroom from the stack to accommodate PTP frames, and so avoiding
skb_realloc_headroom() & co, and the crashes no longer occur.
There's no reason not to set needed_headroom to a large enough
value to accommodate PTP frames, so in this regard this patch
is a fix.
Reported-by: James Jurack <james.jurack@ametek.com> Fixes: bee9e58c9e98 ("gianfar:don't add FCB length to hard_header_len") Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com> Link: https://lore.kernel.org/r/20201020173605.1173-1-claudiu.manoil@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When PTP timestamping is enabled on Tx, the controller
inserts the Tx timestamp at the beginning of the frame
buffer, between SFD and the L2 frame header. This means
that the skb provided by the stack is required to have
enough headroom otherwise a new skb needs to be created
by the driver to accommodate the timestamp inserted by h/w.
Up until now the driver was relying on skb_realloc_headroom()
to create new skbs to accommodate PTP frames. Turns out that
this method is not reliable in this context at least, as
skb_realloc_headroom() for PTP frames can cause random crashes,
mostly in subsequent skb_*() calls, when multiple concurrent
TCP streams are run at the same time with the PTP flow
on the same device (as seen in James' report). I also noticed
that when the system is loaded by sending multiple TCP streams,
the driver receives cloned skbs in large numbers.
skb_cow_head() instead proves to be stable in this scenario,
and not only handles cloned skbs too but it's also more efficient
and widely used in other drivers.
The commit introducing skb_realloc_headroom in the driver
goes back to 2009, commit 93c1285c5d92
("gianfar: reallocate skb when headroom is not enough for fcb").
For practical purposes I'm referencing a newer commit (from 2012)
that brings the code to its current structure (and fixes the PTP
case).
Fixes: 9c4886e5e63b ("gianfar: Fix invalid TX frames returned on error queue when time stamping") Reported-by: James Jurack <james.jurack@ametek.com> Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com> Link: https://lore.kernel.org/r/20201029081057.8506-1-claudiu.manoil@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Correct skb refcount in alloc_ctrl_skb(), causing skb memleak
when chtls_send_abort() called with NULL skb.
it was always leaking the skb, correct it by incrementing skb
refs by one.
work request skb queued in chtls_setkey() won't be freed
because resources are already cleaned for this connection,
fix it by not queuing work request while socket is closing.
v1->v2:
- fix W=1 warning.
v2->v3:
- separate it out from another memleak fix.
In my test setup, I had a SAMA5D27 device configured with ip forwarding, and
second device with usb ethernet (r8152) sending ICMP packets. If the packet
was larger than about 220 bytes, the SAMA5 device would "oops" with the
following trace:
kernel BUG at net/core/skbuff.c:1863!
Internal error: Oops - BUG: 0 [#1] ARM
Modules linked in: xt_MASQUERADE ppp_async ppp_generic slhc iptable_nat xt_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 can_raw can bridge stp llc ipt_REJECT nf_reject_ipv4 sd_mod cdc_ether usbnet usb_storage r8152 scsi_mod mii o
ption usb_wwan usbserial micrel macb at91_sama5d2_adc phylink gpio_sama5d2_piobu m_can_platform m_can industrialio_triggered_buffer kfifo_buf of_mdio can_dev fixed_phy sdhci_of_at91 sdhci_pltfm libphy sdhci mmc_core ohci_at91 ehci_atmel o
hci_hcd iio_rescale industrialio sch_fq_codel spidev prox2_hal(O)
CPU: 0 PID: 0 Comm: swapper Tainted: G O 5.9.1-prox2+ #1
Hardware name: Atmel SAMA5
PC is at skb_put+0x3c/0x50
LR is at macb_start_xmit+0x134/0xad0 [macb]
pc : [<c05258cc>] lr : [<bf0ea5b8>] psr: 20070113
sp : c0d01a60 ip : c07232c0 fp : c4250000
r10: c0d03cc8 r9 : 00000000 r8 : c0d038c0
r7 : 00000000 r6 : 00000008 r5 : c59b66c0 r4 : 0000002a
r3 : 8f659eff r2 : c59e9eea r1 : 00000001 r0 : c59b66c0
Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
Control: 10c53c7d Table: 2640c059 DAC: 00000051
Process swapper (pid: 0, stack limit = 0x75002d81)
The solution was to force nonlinear buffers to be cloned. This was previously
reported by Klaus Doth (https://www.spinics.net/lists/netdev/msg556937.html)
but never formally submitted as a patch.
This is the third revision, hopefully the formatting is correct this time!
Suggested-by: Klaus Doth <krnl@doth.eu> Fixes: 653e92a9175e ("net: macb: add support for padding and fcs computation") Signed-off-by: Mark Deneen <mdeneen@saucontech.com> Link: https://lore.kernel.org/r/20201030155814.622831-1-mdeneen@saucontech.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
int status;
int thread = waitpid(-1, &status, 0);
assert(thread > 0 && thread != pid);
assert(status == 0x80137f);
return 0;
}
fails and triggers WARN_ON_ONCE(!signr) in do_jobctl_trap().
This is because task_join_group_stop() has 2 problems when current is traced:
1. We can't rely on the "JOBCTL_STOP_PENDING" check, a stopped tracee
can be woken up by debugger and it can clone another thread which
should join the group-stop.
We need to check group_stop_count || SIGNAL_STOP_STOPPED.
2. If SIGNAL_STOP_STOPPED is already set, we should not increment
sig->group_stop_count and add JOBCTL_STOP_CONSUME. The new thread
should stop without another do_notify_parent_cldstop() report.
To clarify, the problem is very old and we should blame
ptrace_init_task(). But now that we have task_join_group_stop() it makes
more sense to fix this helper to avoid the code duplication.
==================================================================
BUG: KASAN: use-after-free in tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759
Read of size 1 at addr ffff88805e6b3571 by task kworker/0:6/3850
CPU: 0 PID: 3850 Comm: kworker/0:6 Not tainted 5.8.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events tipc_net_finalize_work
Fix it by calling flush_scheduled_work() to make sure the
tipc_net_finalize_work() stopped before releasing bcbase object.
Reported-by: syzbot+6ea1f7a8df64596ef4d7@syzkaller.appspotmail.com Reported-by: syzbot+e9cc557752ab126c1b99@syzkaller.appspotmail.com Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Hoang Huu Le <hoang.h.le@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As the error capture will compress user buffers as directed to by the
user, it can take an arbitrary amount of time and space. Break up the
compression loops with a call to cond_resched(), that will allow other
processes to schedule (avoiding the soft lockups) and also serve as a
warning should we try to make this loop atomic in the future.
Currently in case of alignment or FCS error if the packet cannot be
corrected it's still not dropped. Report the error properly and drop the
packet while making the code around a little bit more readable.
The "cb_pcidas" driver supports asynchronous commands on the analog
output (AO) subdevice for those boards that have an AO FIFO. The code
(in `cb_pcidas_ao_check_chanlist()` and `cb_pcidas_ao_cmd()`) to
validate and set up the command supports output to a single channel or
to two channels simultaneously (the boards have two AO channels).
However, the code in `cb_pcidas_auto_attach()` that initializes the
subdevices neglects to initialize the AO subdevice's `len_chanlist`
member, leaving it set to 0, but the Comedi core will "correct" it to 1
if the driver neglected to set it. This limits commands to use a single
channel (either channel 0 or 1), but the limit should be two channels.
Set the AO subdevice's `len_chanlist` member to be the same value as the
`n_chan` member, which will be 2.
The DBGD{CCINT,SCRext} and DBGVCR register entries in the cp14 array
are missing their target register, resulting in all accesses being
targetted at the guard sysreg (indexed by __INVALID_SYSREG__).
Point the emulation code at the actual register entries.
It appears that firmware nodes can be shared between devices. In such case
when a (child) device is about to be deleted, its firmware node may be shared
and ACPI_COMPANION_SET(..., NULL) call for it breaks the secondary link
of the shared primary firmware node.
In order to prevent that, check, if the device has a parent and parent's
firmware node is shared with its child, and avoid crashing the link.
Fixes: c15e1bdda436 ("device property: Fix the secondary firmware node handling in set_primary_fwnode()") Reported-by: Ferry Toth <fntoth@gmail.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Tested-by: Ferry Toth <fntoth@gmail.com> Cc: 5.9+ <stable@vger.kernel.org> # 5.9+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Behind primary and secondary we understand the type of the nodes
which might define their ordering. However, if primary node gone,
we can't maintain the ordering by definition of the linked list.
Thus, by ordering secondary node becomes first in the list.
But in this case the meaning of it is still secondary (or auxiliary).
The type of the node is maintained by the secondary pointer in it:
secondary pointer Meaning
NULL or valid primary node
ERR_PTR(-ENODEV) secondary node
So, if by some reason we do the following sequence of calls
This concept is supported by the description of set_primary_fwnode()
along with implementation of set_secondary_fwnode(). Hence, fix
the commit c15e1bdda436 to follow this as well.
Fixes: c15e1bdda436 ("device property: Fix the secondary firmware node handling in set_primary_fwnode()") Cc: Ferry Toth <fntoth@gmail.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Tested-by: Ferry Toth <fntoth@gmail.com> Cc: 5.9+ <stable@vger.kernel.org> # 5.9+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit f6361c6b3880 ("ARM: S3C24XX: remove separate restart code")
removed usage of the watchdog reset platform code in favor of the
Samsung SoC watchdog driver. However the latter was not selected thus
S3C24xx platforms lost reset abilities.
Cc: <stable@vger.kernel.org> Fixes: f6361c6b3880 ("ARM: S3C24XX: remove separate restart code") Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Selecting CONFIG_SAMSUNG_PM_DEBUG (depending on CONFIG_DEBUG_LL) but
without CONFIG_MMU leads to build errors:
arch/arm/plat-samsung/pm-debug.c: In function ‘s3c_pm_uart_base’:
arch/arm/plat-samsung/pm-debug.c:57:2: error:
implicit declaration of function ‘debug_ll_addr’ [-Werror=implicit-function-declaration]
Fixes: 99b2fc2b8b40 ("ARM: SAMSUNG: Use debug_ll_addr() to get UART base address") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200910154150.3318-1-krzk@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
projects / users / dwmw2 / linux.git / log