Sudeep Holla [Wed, 2 Jun 2021 20:54:52 +0000 (21:54 +0100)]
Merge branch 'for-next/scmi' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into for-linux-next
* 'for-next/scmi' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
firmware: arm_scmi: Reset Rx buffer to max size during async commands
firmware: arm_scmi: Add SMCCC discovery dependency in Kconfig
firmware: arm_scmi: Add clock management to the SCMI power domain
Sudeep Holla [Wed, 2 Jun 2021 20:54:39 +0000 (21:54 +0100)]
Merge tag 'arm-ffa-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into for-linux-next
Arm Firmware Framework for ARMv8-A(FFA) interface driver
The Arm FFA specification describes a software architecture to
leverages the virtualization extension to isolate software images
provided by an ecosystem of vendors from each other and describes
interfaces that standardize communication between the various software
images including communication between images in the Secure world and
Normal world. Any Hypervisor could use the FFA interfaces to enable
communication between VMs it manages.
The Hypervisor a.k.a Partition managers in FFA terminology can assign
system resources(Memory regions, Devices, CPU cycles) to the partitions
and manage isolation amongst them.
This is the initial and minimal support for the FFA interface to enable
communication between secure partitions and the normal world OS.
* tag 'arm-ffa-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
firmware: arm_ffa: Add support for MEM_* interfaces
firmware: arm_ffa: Setup in-kernel users of FFA partitions
firmware: arm_ffa: Add support for SMCCC as transport to FFA driver
firmware: arm_ffa: Add initial Arm FFA driver support
firmware: arm_ffa: Add initial FFA bus support for device enumeration
arm64: smccc: Add support for SMCCCv1.2 extended input/output registers
Cristian Marussi [Tue, 1 Jun 2021 10:24:17 +0000 (11:24 +0100)]
firmware: arm_scmi: Reset Rx buffer to max size during async commands
During an async commands execution the Rx buffer length is at first set
to max_msg_sz when the synchronous part of the command is first sent.
However once the synchronous part completes the transport layer waits
for the delayed response which will be processed using the same xfer
descriptor initially allocated. Since synchronous response received at
the end of the xfer will shrink the Rx buffer length to the effective
payload response length, it needs to be reset again.
Raise the Rx buffer length again to max_msg_sz before fetching the
delayed response to ensure full response is read correctly from the
shared memory.
Link: https://lore.kernel.org/r/20210601102421.26581-2-cristian.marussi@arm.com Fixes: 58ecdf03dbb9 ("firmware: arm_scmi: Add support for asynchronous commands and delayed response") Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
[sudeep.holla: moved reset to scmi_handle_response as it could race with
do_xfer_with_response] Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Wong Vee Khee [Wed, 2 Jun 2021 02:31:25 +0000 (10:31 +0800)]
net: stmmac: fix issue where clk is being unprepared twice
In the case of MDIO bus registration failure due to no external PHY
devices is connected to the MAC, clk_disable_unprepare() is called in
stmmac_bus_clk_config() and intel_eth_pci_probe() respectively.
The second call in intel_eth_pci_probe() will caused the following:-
Removing the stmmac_bus_clks_config() call in stmmac_dvr_probe and let
dwmac-intel to handle the unprepare and disable of the clk device.
Fixes: 5ec55823438e ("net: stmmac: add clocks management for gmac driver") Cc: Joakim Zhang <qiangqing.zhang@nxp.com> Signed-off-by: Wong Vee Khee <vee.khee.wong@linux.intel.com> Reviewed-by: Joakim Zhang <qiangqing.zhang@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Josh Triplett [Wed, 2 Jun 2021 01:38:41 +0000 (18:38 -0700)]
net: ipconfig: Don't override command-line hostnames or domains
If the user specifies a hostname or domain name as part of the ip=
command-line option, preserve it and don't overwrite it with one
supplied by DHCP/BOOTP.
For instance, ip=::::myhostname::dhcp will use "myhostname" rather than
ignoring and overwriting it.
Fix the comment on ic_bootp_string that suggests it only copies a string
"if not already set"; it doesn't have any such logic.
Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 59438b46471a ("security,lockdown,selinux: implement SELinux lockdown")
added an implementation of the locked_down LSM hook to SELinux, with the aim
to restrict which domains are allowed to perform operations that would breach
lockdown. This is indirectly also getting audit subsystem involved to report
events. The latter is problematic, as reported by Ondrej and Serhei, since it
can bring down the whole system via audit:
1) The audit events that are triggered due to calls to security_locked_down()
can OOM kill a machine, see below details [0].
2) It also seems to be causing a deadlock via avc_has_perm()/slow_avc_audit()
when trying to wake up kauditd, for example, when using trace_sched_switch()
tracepoint, see details in [1]. Triggering this was not via some hypothetical
corner case, but with existing tools like runqlat & runqslower from bcc, for
example, which make use of this tracepoint. Rough call sequence goes like:
What's worse is that the intention of 59438b46471a to further restrict lockdown
settings for specific applications in respect to the global lockdown policy is
completely broken for BPF. The SELinux policy rule for the current lockdown check
looks something like this:
allow <who> <who> : lockdown { <reason> };
However, this doesn't match with the 'current' task where the security_locked_down()
is executed, example: httpd does a syscall. There is a tracing program attached
to the syscall which triggers a BPF program to run, which ends up doing a
bpf_probe_read_kernel{,_str}() helper call. The selinux_lockdown() hook does
the permission check against 'current', that is, httpd in this example. httpd
has literally zero relation to this tracing program, and it would be nonsensical
having to write an SELinux policy rule against httpd to let the tracing helper
pass. The policy in this case needs to be against the entity that is installing
the BPF program. For example, if bpftrace would generate a histogram of syscall
counts by user space application:
bpftrace would then go and generate a BPF program from this internally. One way
of doing it [for the sake of the example] could be to call bpf_get_current_task()
helper and then access current->comm via one of bpf_probe_read_kernel{,_str}()
helpers. So the program itself has nothing to do with httpd or any other random
app doing a syscall here. The BPF program _explicitly initiated_ the lockdown
check. The allow/deny policy belongs in the context of bpftrace: meaning, you
want to grant bpftrace access to use these helpers, but other tracers on the
system like my_random_tracer _not_.
Therefore fix all three issues at the same time by taking a completely different
approach for the security_locked_down() hook, that is, move the check into the
program verification phase where we actually retrieve the BPF func proto. This
also reliably gets the task (current) that is trying to install the BPF tracing
program, e.g. bpftrace/bcc/perf/systemtap/etc, and it also fixes the OOM since
we're moving this out of the BPF helper's fast-path which can be called several
millions of times per second.
The check is then also in line with other security_locked_down() hooks in the
system where the enforcement is performed at open/load time, for example,
open_kcore() for /proc/kcore access or module_sig_check() for module signatures
just to pick few random ones. What's out of scope in the fix as well as in
other security_locked_down() hook locations /outside/ of BPF subsystem is that
if the lockdown policy changes on the fly there is no retrospective action.
This requires a different discussion, potentially complex infrastructure, and
it's also not clear whether this can be solved generically. Either way, it is
out of scope for a suitable stable fix which this one is targeting. Note that
the breakage is specifically on 59438b46471a where it started to rely on 'current'
as UAPI behavior, and _not_ earlier infrastructure such as 9d1f8be5cf42 ("bpf:
Restrict bpf when kernel lockdown is in confidentiality mode").
[0] https://bugzilla.redhat.com/show_bug.cgi?id=1955585, Jakub Hrozek says:
I starting seeing this with F-34. When I run a container that is traced with
BPF to record the syscalls it is doing, auditd is flooded with messages like:
type=AVC msg=audit(1619784520.593:282387): avc: denied { confidentiality }
for pid=476 comm="auditd" lockdown_reason="use of bpf to read kernel RAM"
scontext=system_u:system_r:auditd_t:s0 tcontext=system_u:system_r:auditd_t:s0
tclass=lockdown permissive=0
This seems to be leading to auditd running out of space in the backlog buffer
and eventually OOMs the machine.
Upstream kernel 5.11.0-rc7 and later was found to deadlock during a
bpf_probe_read_compat() call within a sched_switch tracepoint. The problem
is reproducible with the reg_alloc3 testcase from SystemTap's BPF backend
testsuite on x86_64 as well as the runqlat, runqslower tools from bcc on
ppc64le. Example stack trace:
projects / users / jedix / linux-maple.git / log