Jan Kara [Thu, 15 Jun 2023 11:38:48 +0000 (13:38 +0200)]
fs: Protect reconfiguration of sb read-write from racing writes
The reconfigure / remount code takes a lot of effort to protect
filesystem's reconfiguration code from racing writes on remounting
read-only. However during remounting read-only filesystem to read-write
mode userspace writes can start immediately once we clear SB_RDONLY
flag. This is inconvenient for example for ext4 because we need to do
some writes to the filesystem (such as preparation of quota files)
before we can take userspace writes so we are clearing SB_RDONLY flag
before we are fully ready to accept userpace writes and syzbot has found
a way to exploit this [1]. Also as far as I'm reading the code
the filesystem remount code was protected from racing writes in the
legacy mount path by the mount's MNT_READONLY flag so this is relatively
new problem. It is actually fairly easy to protect remount read-write
from racing writes using sb->s_readonly_remount flag so let's just do
that instead of having to workaround these races in the filesystem code.
Jeff Layton [Mon, 12 Jun 2023 10:45:19 +0000 (06:45 -0400)]
autofs: set ctime as well when mtime changes on a dir
When adding entries to a directory, POSIX generally requires that the
ctime also be updated alongside the mtime.
Signed-off-by: Jeff Layton <jlayton@kernel.org> Acked-by: Ian Kent <raven@themaw.net>
Message-Id: <20230612104524.17058-4-jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
Fabio M. De Francesco [Fri, 9 Jun 2023 14:59:37 +0000 (16:59 +0200)]
fs/aio: Stop allocating aio rings from HIGHMEM
There is no need to allocate aio rings from HIGHMEM because of very
little memory needed here.
Therefore, use GFP_USER flag in find_or_create_page() and get rid of
kmap*() mappings.
Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ira Weiny <ira.weiny@intel.com> Suggested-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Message-Id: <20230609145937.17610-1-fmdefrancesco@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
Mao Zhu [Sun, 11 Jun 2023 12:33:14 +0000 (08:33 -0400)]
fs: Fix comment typo
Delete duplicated word in comment.
Signed-off-by: Mao Zhu <zhumao001@208suo.com>
Message-Id: <20230611123314.5282-1-dengshaomin@cdjrlc.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
Thomas Weißschuh [Wed, 7 Jun 2023 17:28:48 +0000 (19:28 +0200)]
fs: avoid empty option when generating legacy mount string
As each option string fragment is always prepended with a comma it would
happen that the whole string always starts with a comma. This could be
interpreted by filesystem drivers as an empty option and may produce
errors.
For example the NTFS driver from ntfs.ko behaves like this and fails
when mounted via the new API.
Link: https://github.com/util-linux/util-linux/issues/2298 Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Fixes: 3e1aeb00e6d1 ("vfs: Implement a filesystem superblock creation/configuration context") Cc: stable@vger.kernel.org
Message-Id: <20230607-fs-empty-option-v1-1-20c8dbf4671b@weissschuh.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
NULL the dangling pipe reference while clearing watch_queue.
If not done, a reference to a freed pipe remains in the watch_queue,
as this function is called before freeing a pipe in free_pipe_info()
(see line 834 of fs/pipe.c).
The sole use of wqueue->defunct is for checking if the watch queue has
been cleared, but wqueue->pipe is also NULLed while clearing.
Thus, wqueue->defunct is superfluous, as wqueue->pipe can be checked
for NULL. Hence, the former can be removed.
Tested with keyutils testsuite.
Cc: stable@vger.kernel.org # 6.1 Signed-off-by: Siddh Raman Pant <code@siddh.me> Acked-by: David Howells <dhowells@redhat.com>
Message-Id: <20230605143616.640517-1-code@siddh.me> Signed-off-by: Christian Brauner <brauner@kernel.org>
chenzhiyin [Thu, 1 Jun 2023 09:24:00 +0000 (05:24 -0400)]
fs.h: Optimize file struct to prevent false sharing
In the syscall test of UnixBench, performance regression occurred due
to false sharing.
The lock and atomic members, including file::f_lock, file::f_count and
file::f_pos_lock are highly contended and frequently updated in the
high-concurrency test scenarios. perf c2c indentified one affected
read access, file::f_op.
To prevent false sharing, the layout of file struct is changed as
following
(A) f_lock, f_count and f_pos_lock are put together to share the same
cache line.
(B) The read mostly members, including f_path, f_inode, f_op are put
into a separate cache line.
(C) f_mode is put together with f_count, since they are used frequently
at the same time.
Due to '__randomize_layout' attribute of file struct, the updated layout
only can be effective when CONFIG_RANDSTRUCT_NONE is 'y'.
The optimization has been validated in the syscall test of UnixBench.
performance gain is 30~50%. Furthermore, to confirm the optimization
effectiveness on the other codes path, the results of fsdisk, fsbuffer
and fstime are also shown.
Fabio M. De Francesco [Fri, 2 Jun 2023 10:33:07 +0000 (12:33 +0200)]
highmem: Rename put_and_unmap_page() to unmap_and_put_page()
With commit 849ad04cf562a ("new helper: put_and_unmap_page()"), Al Viro
introduced the put_and_unmap_page() to use in those many places where we
have a common pattern consisting of calls to kunmap_local() +
put_page().
Obviously, first we unmap and then we put pages. Instead, the original
name of this helper seems to imply that we first put and then unmap.
Therefore, rename the helper and change the only known upstreamed user
(i.e., fs/sysv) before this helper enters common use and might become
difficult to find all call sites and instead easy to break the builds.
Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Reviewed-by: Eric Biggers <ebiggers@google.com>
Message-Id: <20230602103307.5637-1-fmdefrancesco@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
David Howells [Fri, 19 May 2023 17:21:20 +0000 (18:21 +0100)]
cachefiles: Allow the cache to be non-root
Set mode 0600 on files in the cache so that cachefilesd can run as an
unprivileged user rather than leaving the files all with 0. Directories
are already set to 0700.
Userspace then needs to set the uid and gid before issuing the "bind"
command and the cache must've been chown'd to those IDs.
Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
cc: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-erofs@lists.ozlabs.org
cc: linux-fsdevel@vger.kernel.org
Message-Id: <1853230.1684516880@warthog.procyon.org.uk> Signed-off-by: Christian Brauner <brauner@kernel.org>
Yihuan Pan [Sat, 20 May 2023 07:23:32 +0000 (15:23 +0800)]
init: remove unused names parameter in split_fs_names()
The split_fs_names() function takes a names parameter, but the function
actually uses the root_fs_names global variable instead. This names
parameter is not used in the function, so it can be safely removed.
This change does not affect the functionality of split_fs_names() or any
other part of the kernel.
Signed-off-by: Yihuan Pan <xun794@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
Message-Id: <4lsiigvaw4lxcs37rlhgepv77xyxym6krkqcpc3xfncnswok3y@b67z3b44orar> Signed-off-by: Christian Brauner <brauner@kernel.org>
As loff_t is a signed type, we should use the safe overflow checks
instead of relying on compiler implementation.
The bogus values are intentional and the test is supposed to verify the
boundary conditions.
Signed-off-by: David Sterba <dsterba@suse.com>
Message-Id: <20230523162628.17071-1-dsterba@suse.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
The arch_report_meminfo() function is provided by four architectures,
with a __weak fallback in procfs itself. On architectures that don't
have a custom version, the __weak version causes a warning because
of the missing prototype.
Remove the architecture specific prototypes and instead add one
in linux/proc_fs.h.
Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> # for arch/x86 Acked-by: Helge Deller <deller@gmx.de> # parisc Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Message-Id: <20230516195834.551901-1-arnd@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
Arnd Bergmann [Tue, 16 May 2023 19:56:12 +0000 (21:56 +0200)]
fs: pipe: reveal missing function protoypes
A couple of functions from fs/pipe.c are used both internally
and for the watch queue code, but the declaration is only
visible when the latter is enabled:
fs/pipe.c:1254:5: error: no previous prototype for 'pipe_resize_ring'
fs/pipe.c:758:15: error: no previous prototype for 'account_pipe_buffers'
fs/pipe.c:764:6: error: no previous prototype for 'too_many_pipe_buffers_soft'
fs/pipe.c:771:6: error: no previous prototype for 'too_many_pipe_buffers_hard'
fs/pipe.c:777:6: error: no previous prototype for 'pipe_is_unprivileged_user'
Make the visible unconditionally to avoid these warnings.
Fixes: c73be61cede5 ("pipe: Add general notification queue support") Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Message-Id: <20230516195629.551602-1-arnd@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
Vladimir Sementsov-Ogievskiy [Thu, 20 Apr 2023 12:04:09 +0000 (15:04 +0300)]
coredump: require O_WRONLY instead of O_RDWR
The motivation for this patch has been to enable using a stricter
apparmor profile to prevent programs from reading any coredump in the
system.
However, this became something else. The following details are based on
Christian's and Linus' archeology into the history of the number "2" in
the coredump handling code.
To make sure we're not accidently introducing some subtle behavioral
change into the coredump code we set out on a voyage into the depths of
history.git to figure out why this was O_RDWR in the first place.
Coredump handling was introduced over 30 years ago in commit ddc733f452e0 ("[PATCH] Linux-0.97 (August 1, 1992)").
The original code used O_WRONLY:
However, this changed in 1993 and starting with commit 9cb9f18b5d26 ("[PATCH] Linux-0.99.10 (June 7, 1993)") the coredump code
suddenly used the constant "2":
This was curious as in the same commit the kernel switched from
constants to proper defines in other places such as KERNEL_DS and
USER_DS and O_RDWR did already exist.
So why was "2" used? It turns out that open_namei() - an early version
of what later turned into filp_open() - didn't accept O_RDWR.
A semantic quirk of the open() uapi is the definition of the O_RDONLY
flag. It would seem natural to define:
#define O_RDWR (O_RDONLY | O_WRONLY)
but that isn't possible because:
#define O_RDONLY 0
This makes O_RDONLY effectively meaningless when passed to the kernel.
In other words, there has never been a way - until O_PATH at least - to
open a file without any permission; O_RDONLY was always implied on the
uapi side while the kernel does in fact allow opening files without
permissions.
The trouble comes when trying to map the uapi flags onto the
corresponding file mode flags FMODE_{READ,WRITE}. This mapping still
happens today and is causing issues to this day (We ran into this
during additions for openat2() for example.).
So the special value "3" was used to indicate that the file was opened
for special access:
f->f_flags = flag = flags;
f->f_mode = (flag+1) & O_ACCMODE;
if (f->f_mode)
flag++;
This allowed the file mode to be set to FMODE_READ | FMODE_WRITE mapping
the O_{RDONLY,WRONLY,RDWR} flags into the FMODE_{READ,WRITE} flags. The
special access then required read-write permissions and 0 was used to
access symlinks.
But back when ddc733f452e0 ("[PATCH] Linux-0.97 (August 1, 1992)") added
coredump handling open_namei() took the FMODE_{READ,WRITE} flags as an
argument. So the coredump handling introduced in ddc733f452e0 ("[PATCH] Linux-0.97 (August 1, 1992)") was buggy because
O_WRONLY shouldn't have been passed. Since O_WRONLY is 1 but
open_namei() took FMODE_{READ,WRITE} it was passed FMODE_READ on
accident.
So 9cb9f18b5d26 ("[PATCH] Linux-0.99.10 (June 7, 1993)") was a bugfix
for this and the 2 didn't really mean O_RDWR, it meant FMODE_WRITE which
was correct.
The clue is that FMODE_{READ,WRITE} didn't exist yet and thus a raw "2"
value was passed.
Fast forward 5 years when around 2.2.4pre4 (February 16, 1999) this code
was changed to:
At this point the raw "2" should have become O_WRONLY again as
filp_open() didn't take FMODE_{READ,WRITE} but O_{RDONLY,WRONLY,RDWR}.
Another 17 years later, the code was changed again cementing the mistake
and making it almost impossible to detect when commit 378c6520e7d2 ("fs/coredump: prevent fsuid=0 dumps into user-controlled directories")
replaced the raw "2" with O_RDWR.
And now, here we are with this patch that sent us on a quest to answer
the big questions in life such as "Why are coredump files opened with
O_RDWR?" and "Is it safe to just use O_WRONLY?".
So with this commit we're reintroducing O_WRONLY again and bringing this
code back to its original state when it was first introduced in commit ddc733f452e0 ("[PATCH] Linux-0.97 (August 1, 1992)") over 30 years ago.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20230420120409.602576-1-vsementsov@yandex-team.ru>
[brauner@kernel.org: completely rewritten commit message] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
Min-Hua Chen [Tue, 2 May 2023 23:22:08 +0000 (07:22 +0800)]
fs: fix incorrect fmode_t casts
Use __FMODE_NONOTIFY instead of FMODE_NONOTIFY to fixes
the following sparce warnings:
fs/overlayfs/file.c:48:37: sparse: warning: restricted fmode_t degrades to integer
fs/overlayfs/file.c:128:13: sparse: warning: restricted fmode_t degrades to integer
fs/open.c:1159:21: sparse: warning: restricted fmode_t degrades to integer
Signed-off-by: Min-Hua Chen <minhuadotchen@gmail.com>
Message-Id: <20230502232210.119063-1-minhuadotchen@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
Also update definition when CONFIG_JFFS2_FS_XATTR is not enabled
Tested with an MTD mount point and some user set/getfattr.
Many current target on OpenWRT also suffer from a compilation warning
(that become an error with CONFIG_WERROR) with the following output:
fs/jffs2/xattr.c: In function 'jffs2_build_xattr_subsystem':
fs/jffs2/xattr.c:887:1: error: the frame size of 1088 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
887 | }
| ^
Using dynamic allocation fix this compilation warning.
Fixes: c9f700f840bd ("[JFFS2][XATTR] using 'delete marker' for xdatum/xref deletion") Reported-by: Tim Gardner <tim.gardner@canonical.com> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Ron Economos <re@w6rz.net> Reported-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com> Cc: stable@vger.kernel.org
Message-Id: <20230506045612.16616-1-ansuelsmth@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
Anuradha Weeraman [Sat, 6 May 2023 18:29:27 +0000 (23:59 +0530)]
fs/open.c: Fix W=1 kernel doc warnings
fs/open.c: In functions 'setattr_vfsuid' and 'setattr_vfsgid':
warning: Function parameter or member 'attr' not described
- Fix warning by removing kernel-doc for these as they are static
inline functions and not required to be exposed via kernel-doc.
fs/open.c:
warning: Excess function parameter 'opened' description in 'finish_open'
warning: Excess function parameter 'cred' description in 'vfs_open'
- Fix by removing the parameters from the kernel-doc as they are no
longer required by the function.
Signed-off-by: Anuradha Weeraman <anuradha@debian.org>
Message-Id: <20230506182928.384105-1-anuradha@debian.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
Azeem Shaikh [Wed, 10 May 2023 22:11:19 +0000 (22:11 +0000)]
vfs: Replace all non-returning strlcpy with strscpy
strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.
Linus Torvalds [Sun, 14 May 2023 19:32:34 +0000 (12:32 -0700)]
Merge tag 'cxl-fixes-6.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl
Pull compute express link fixes from Dan Williams:
- Fix a compilation issue with DEFINE_STATIC_SRCU() in the unit tests
- Fix leaking kernel memory to a root-only sysfs attribute
* tag 'cxl-fixes-6.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
cxl: Add missing return to cdat read error path
tools/testing/cxl: Use DEFINE_STATIC_SRCU()
Linus Torvalds [Sun, 14 May 2023 16:54:38 +0000 (09:54 -0700)]
Merge tag 'parisc-for-6.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc architecture fixes from Helge Deller:
- Fix encoding of swp_entry due to added SWP_EXCLUSIVE flag
- Include reboot.h to avoid gcc-12 compiler warning
* tag 'parisc-for-6.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Fix encoding of swp_entry due to added SWP_EXCLUSIVE flag
parisc: kexec: include reboot.h
Linus Torvalds [Sun, 14 May 2023 15:00:46 +0000 (08:00 -0700)]
Merge tag 'locking_urgent_for_v6.4_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fix from Borislav Petkov:
- Make sure __down_read_common() is always inlined so that the callers'
names land in traceevents output and thus the blocked function can be
identified
* tag 'locking_urgent_for_v6.4_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/rwsem: Add __always_inline annotation to __down_read_common() and inlined callers
Linus Torvalds [Sun, 14 May 2023 14:56:51 +0000 (07:56 -0700)]
Merge tag 'perf_urgent_for_v6.4_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Borislav Petkov:
- Make sure the PEBS buffer is flushed before reprogramming the
hardware so that the correct record sizes are used
- Update the sample size for AMD BRS events
- Fix a confusion with using the same on-stack struct with different
events in the event processing path
* tag 'perf_urgent_for_v6.4_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/ds: Flush PEBS DS when changing PEBS_DATA_CFG
perf/x86: Fix missing sample size update on AMD BRS
perf/core: Fix perf_sample_data not properly initialized for different swevents in perf_tp_event()
Linus Torvalds [Sun, 14 May 2023 14:44:48 +0000 (07:44 -0700)]
Merge tag 'x86_urgent_for_v6.4_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fix from Borislav Petkov:
- Add the required PCI IDs so that the generic SMN accesses provided by
amd_nb.c work for drivers which switch to them. Add a PCI device ID
to k10temp's table so that latter is loaded on such systems too
* tag 'x86_urgent_for_v6.4_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
hwmon: (k10temp) Add PCI ID for family 19, model 78h
x86/amd_nb: Add PCI ID for family 19h model 78h
Linus Torvalds [Sun, 14 May 2023 14:39:15 +0000 (07:39 -0700)]
Merge tag 'timers_urgent_for_v6.4_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Borislav Petkov:
- Prevent CPU state corruption when an active clockevent broadcast
device is replaced while the system is already in oneshot mode
* tag 'timers_urgent_for_v6.4_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tick/broadcast: Make broadcast device replacement work correctly
Linus Torvalds [Sun, 14 May 2023 00:45:39 +0000 (17:45 -0700)]
Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
"Some ext4 bug fixes (mostly to address Syzbot reports)"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: bail out of ext4_xattr_ibody_get() fails for any reason
ext4: add bounds checking in get_max_inline_xattr_value_size()
ext4: add indication of ro vs r/w mounts in the mount message
ext4: fix deadlock when converting an inline directory in nojournal mode
ext4: improve error recovery code paths in __ext4_remount()
ext4: improve error handling from ext4_dirhash()
ext4: don't clear SB_RDONLY when remounting r/w until quota is re-enabled
ext4: check iomap type only if ext4_iomap_begin() does not fail
ext4: avoid a potential slab-out-of-bounds in ext4_group_desc_csum
ext4: fix data races when using cached status extents
ext4: avoid deadlock in fs reclaim with page writeback
ext4: fix invalid free tracking in ext4_xattr_move_to_block()
ext4: remove a BUG_ON in ext4_mb_release_group_pa()
ext4: allow ext4_get_group_info() to fail
ext4: fix lockdep warning when enabling MMP
ext4: fix WARNING in mb_find_extent
Linus Torvalds [Sun, 14 May 2023 00:37:32 +0000 (17:37 -0700)]
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fix from James Bottomley:
"A single small fix for the UFS driver to fix a power management
failure"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: ufs: core: Fix I/O hang that occurs when BKOPS fails in W-LUN suspend
Helge Deller [Sat, 13 May 2023 20:30:06 +0000 (22:30 +0200)]
parisc: Fix encoding of swp_entry due to added SWP_EXCLUSIVE flag
Fix the __swp_offset() and __swp_entry() macros due to commit 6d239fc78c0b
("parisc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE") which introduced the
SWP_EXCLUSIVE flag by reusing the _PAGE_ACCESSED flag.
Reported-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de> Tested-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Helge Deller <deller@gmx.de> Fixes: 6d239fc78c0b ("parisc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE") Cc: <stable@vger.kernel.org> # v6.3+
Theodore Ts'o [Fri, 12 May 2023 19:16:27 +0000 (15:16 -0400)]
ext4: bail out of ext4_xattr_ibody_get() fails for any reason
In ext4_update_inline_data(), if ext4_xattr_ibody_get() fails for any
reason, it's best if we just fail as opposed to stumbling on,
especially if the failure is EFSCORRUPTED.
Theodore Ts'o [Fri, 12 May 2023 19:11:02 +0000 (15:11 -0400)]
ext4: add bounds checking in get_max_inline_xattr_value_size()
Normally the extended attributes in the inode body would have been
checked when the inode is first opened, but if someone is writing to
the block device while the file system is mounted, it's possible for
the inode table to get corrupted. Add bounds checking to avoid
reading beyond the end of allocated memory if this happens.
Theodore Ts'o [Fri, 12 May 2023 18:49:57 +0000 (14:49 -0400)]
ext4: add indication of ro vs r/w mounts in the mount message
Whether the file system is mounted read-only or read/write is more
important than the quota mode, which we are already printing. Add the
ro vs r/w indication since this can be helpful in debugging problems
from the console log.
Theodore Ts'o [Sun, 7 May 2023 01:04:01 +0000 (21:04 -0400)]
ext4: fix deadlock when converting an inline directory in nojournal mode
In no journal mode, ext4_finish_convert_inline_dir() can self-deadlock
by calling ext4_handle_dirty_dirblock() when it already has taken the
directory lock. There is a similar self-deadlock in
ext4_incvert_inline_data_nolock() for data files which we'll fix at
the same time.
Theodore Ts'o [Sat, 6 May 2023 02:20:29 +0000 (22:20 -0400)]
ext4: improve error recovery code paths in __ext4_remount()
If there are failures while changing the mount options in
__ext4_remount(), we need to restore the old mount options.
This commit fixes two problem. The first is there is a chance that we
will free the old quota file names before a potential failure leading
to a use-after-free. The second problem addressed in this commit is
if there is a failed read/write to read-only transition, if the quota
has already been suspended, we need to renable quota handling.
Theodore Ts'o [Sat, 6 May 2023 15:59:13 +0000 (11:59 -0400)]
ext4: improve error handling from ext4_dirhash()
The ext4_dirhash() will *almost* never fail, especially when the hash
tree feature was first introduced. However, with the addition of
support of encrypted, casefolded file names, that function can most
certainly fail today.
So make sure the callers of ext4_dirhash() properly check for
failures, and reflect the errors back up to their callers.
Theodore Ts'o [Sat, 6 May 2023 01:02:30 +0000 (21:02 -0400)]
ext4: don't clear SB_RDONLY when remounting r/w until quota is re-enabled
When a file system currently mounted read/only is remounted
read/write, if we clear the SB_RDONLY flag too early, before the quota
is initialized, and there is another process/thread constantly
attempting to create a directory, it's possible to trigger the
WARN_ON_ONCE(dquot_initialize_needed(inode));
in ext4_xattr_block_set(), with the following stack trace:
Baokun Li [Fri, 5 May 2023 13:24:29 +0000 (21:24 +0800)]
ext4: check iomap type only if ext4_iomap_begin() does not fail
When ext4_iomap_overwrite_begin() calls ext4_iomap_begin() map blocks may
fail for some reason (e.g. memory allocation failure, bare disk write), and
later because "iomap->type ! = IOMAP_MAPPED" triggers WARN_ON(). When ext4
iomap_begin() returns an error, it is normal that the type of iomap->type
may not match the expectation. Therefore, we only determine if iomap->type
is as expected when ext4_iomap_begin() is executed successfully.
Replace
le16_to_cpu(sbi->s_es->s_desc_size)
with
sbi->s_desc_size
It reduces ext4's compiled text size, and makes the code more efficient
(we remove an extra indirect reference and a potential byte
swap on big endian systems), and there is no downside. It also avoids the
potential KASAN / syzkaller failure, as a bonus.
Jan Kara [Thu, 4 May 2023 12:55:24 +0000 (14:55 +0200)]
ext4: fix data races when using cached status extents
When using cached extent stored in extent status tree in tree->cache_es
another process holding ei->i_es_lock for reading can be racing with us
setting new value of tree->cache_es. If the compiler would decide to
refetch tree->cache_es at an unfortunate moment, it could result in a
bogus in_range() check. Fix the possible race by using READ_ONCE() when
using tree->cache_es only under ei->i_es_lock for reading.
Jan Kara [Thu, 4 May 2023 12:47:23 +0000 (14:47 +0200)]
ext4: avoid deadlock in fs reclaim with page writeback
Ext4 has a filesystem wide lock protecting ext4_writepages() calls to
avoid races with switching of journalled data flag or inode format. This
lock can however cause a deadlock like:
CPU0 CPU1
ext4_writepages()
percpu_down_read(sbi->s_writepages_rwsem);
ext4_change_inode_journal_flag()
percpu_down_write(sbi->s_writepages_rwsem);
- blocks, all readers block from now on
ext4_do_writepages()
ext4_init_io_end()
kmem_cache_zalloc(io_end_cachep, GFP_KERNEL)
fs_reclaim frees dentry...
dentry_unlink_inode()
iput() - last ref =>
iput_final() - inode dirty =>
write_inode_now()...
ext4_writepages() tries to acquire sbi->s_writepages_rwsem
and blocks forever
Make sure we cannot recurse into filesystem reclaim from writeback code
to avoid the deadlock.
ext4: fix invalid free tracking in ext4_xattr_move_to_block()
In ext4_xattr_move_to_block(), the value of the extended attribute
which we need to move to an external block may be allocated by
kvmalloc() if the value is stored in an external inode. So at the end
of the function the code tried to check if this was the case by
testing entry->e_value_inum.
However, at this point, the pointer to the xattr entry is no longer
valid, because it was removed from the original location where it had
been stored. So we could end up calling kvfree() on a pointer which
was not allocated by kvmalloc(); or we could also potentially leak
memory by not freeing the buffer when it should be freed. Fix this by
storing whether it should be freed in a separate variable.
ext4: remove a BUG_ON in ext4_mb_release_group_pa()
If a malicious fuzzer overwrites the ext4 superblock while it is
mounted such that the s_first_data_block is set to a very large
number, the calculation of the block group can underflow, and trigger
a BUG_ON check. Change this to be an ext4_warning so that we don't
crash the kernel.
Previously, ext4_get_group_info() would treat an invalid group number
as BUG(), since in theory it should never happen. However, if a
malicious attaker (or fuzzer) modifies the superblock via the block
device while it is the file system is mounted, it is possible for
s_first_data_block to get set to a very large number. In that case,
when calculating the block group of some block number (such as the
starting block of a preallocation region), could result in an
underflow and very large block group number. Then the BUG_ON check in
ext4_get_group_info() would fire, resutling in a denial of service
attack that can be triggered by root or someone with write access to
the block device.
For a quality of implementation perspective, it's best that even if
the system administrator does something that they shouldn't, that it
will not trigger a BUG. So instead of BUG'ing, ext4_get_group_info()
will call ext4_error and return NULL. We also add fallback code in
all of the callers of ext4_get_group_info() that it might NULL.
Also, since ext4_get_group_info() was already borderline to be an
inline function, un-inline it. The results in a next reduction of the
compiled text size of ext4 by roughly 2k.
Linus Torvalds [Sat, 13 May 2023 14:51:03 +0000 (09:51 -0500)]
Merge tag 'block-6.4-2023-05-13' of git://git.kernel.dk/linux
Pull block fixes from Jens Axboe:
"Just a few minor fixes for drivers, and a deletion of a file that is
woefully out-of-date these days"
* tag 'block-6.4-2023-05-13' of git://git.kernel.dk/linux:
Documentation/block: drop the request.rst file
ublk: fix command op code check
block/rnbd: replace REQ_OP_FLUSH with REQ_OP_WRITE
nbd: Fix debugfs_create_dir error checking
Linus Torvalds [Fri, 12 May 2023 22:10:32 +0000 (17:10 -0500)]
Merge tag 'for-6.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull more btrfs fixes from David Sterba:
- fix incorrect number of bitmap entries for space cache if loading is
interrupted by some error
- fix backref walking, this breaks a mode of LOGICAL_INO_V2 ioctl that
is used in deduplication tools
- zoned mode fixes:
- properly finish zone reserved for relocation
- correctly calculate super block zone end on ZNS
- properly initialize new extent buffer for redirty
- make mount option clear_cache work with block-group-tree, to rebuild
free-space-tree instead of temporarily disabling it that would lead
to a forced read-only mount
- fix alignment check for offset when printing extent item
* tag 'for-6.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: make clear_cache mount option to rebuild FST without disabling it
btrfs: zero the buffer before marking it dirty in btrfs_redirty_list_add
btrfs: zoned: fix full zone super block reading on ZNS
btrfs: zoned: zone finish data relocation BG with last IO
btrfs: fix backref walking not returning all inode refs
btrfs: fix space cache inconsistency after error loading it from disk
btrfs: print-tree: parent bytenr must be aligned to sector size
Linus Torvalds [Fri, 12 May 2023 22:01:36 +0000 (17:01 -0500)]
Merge tag '6.4-rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs client fixes from Steve French:
- fix for copy_file_range bug for very large files that are multiples
of rsize
- do not ignore "isolated transport" flag if set on share
- set rasize default better
- three fixes related to shutdown and freezing (fixes 4 xfstests, and
closes deferred handles faster in some places that were missed)
* tag '6.4-rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
cifs: release leases for deferred close handles when freezing
smb3: fix problem remounting a share after shutdown
SMB3: force unmount was failing to close deferred close files
smb3: improve parallel reads of large files
do not reuse connection if share marked as isolated
cifs: fix pcchunk length type in smb2_copychunk_range
Linus Torvalds [Fri, 12 May 2023 21:56:09 +0000 (16:56 -0500)]
Merge tag 'vfs/v6.4-rc1/pipe' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fix from Christian Brauner:
"During the pipe nonblock rework the check for both O_NONBLOCK and
IOCB_NOWAIT was dropped. Both checks need to be performed to ensure
that files without O_NONBLOCK but IOCB_NOWAIT don't block when writing
to or reading from a pipe.
This just contains the fix adding the check for IOCB_NOWAIT back in"
* tag 'vfs/v6.4-rc1/pipe' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs:
pipe: check for IOCB_NOWAIT alongside O_NONBLOCK
Linus Torvalds [Fri, 12 May 2023 21:39:05 +0000 (16:39 -0500)]
Merge tag 'io_uring-6.4-2023-05-12' of git://git.kernel.dk/linux
Pull io_uring fix from Jens Axboe:
"Just a single fix making io_uring_sqe_cmd() available regardless of
CONFIG_IO_URING, fixing a regression introduced during the merge
window if nvme was selected but io_uring was not"
* tag 'io_uring-6.4-2023-05-12' of git://git.kernel.dk/linux:
io_uring: make io_uring_sqe_cmd() unconditionally available
Linus Torvalds [Fri, 12 May 2023 21:31:55 +0000 (16:31 -0500)]
Merge tag 'riscv-for-linus-6.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fix from Palmer Dabbelt:
"Just a single fix this week for a build issue. That'd usually be a
good sign, but we've started to get some reports of boot failures on
some hardware/bootloader configurations. Nothing concrete yet, but
I've got a funny feeling that's where much of the bug hunting is going
right now.
Nothing's reproducing on my end, though, and this fixes some pretty
concrete issues so I figured there's no reason to delay it:
- a fix to the linker script to avoid orpahaned sections in
kernel/pi"
* tag 'riscv-for-linus-6.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: Fix orphan section warnings caused by kernel/pi
Jens Axboe [Tue, 9 May 2023 15:12:24 +0000 (09:12 -0600)]
pipe: check for IOCB_NOWAIT alongside O_NONBLOCK
Pipe reads or writes need to enable nonblocking attempts, if either
O_NONBLOCK is set on the file, or IOCB_NOWAIT is set in the iocb being
passed in. The latter isn't currently true, ensure we check for both
before waiting on data or space.
Fixes: afed6271f5b0 ("pipe: set FMODE_NOWAIT on pipes") Signed-off-by: Jens Axboe <axboe@kernel.dk>
Message-Id: <e5946d67-4e5e-b056-ba80-656bab12d9f6@kernel.dk> Signed-off-by: Christian Brauner <brauner@kernel.org>
Ming Lei [Fri, 5 May 2023 15:31:42 +0000 (23:31 +0800)]
ublk: fix command op code check
In case of CONFIG_BLKDEV_UBLK_LEGACY_OPCODES, type of cmd opcode could
be 0 or 'u'; and type can only be 'u' if CONFIG_BLKDEV_UBLK_LEGACY_OPCODES
isn't set.
Ivan Orlov [Fri, 12 May 2023 13:05:32 +0000 (17:05 +0400)]
nbd: Fix debugfs_create_dir error checking
The debugfs_create_dir function returns ERR_PTR in case of error, and the
only correct way to check if an error occurred is 'IS_ERR' inline function.
This patch will replace the null-comparison with IS_ERR.
Linus Torvalds [Fri, 12 May 2023 12:59:08 +0000 (07:59 -0500)]
Merge tag 'firewire-fixes-6.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394
Pull firewire fix from Takashi Sakamoto:
- fix early release of request packet
* tag 'firewire-fixes-6.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
firewire: net: fix unexpected release of object for asynchronous request packet
i915:
- taint kernel when force_probe is used
- NULL deref and div-by-zero fixes for display
- GuC error capture fix for Xe devices"
* tag 'drm-fixes-2023-05-12' of git://anongit.freedesktop.org/drm/drm: (24 commits)
drm/amdgpu: change gfx 11.0.4 external_id range
drm/amdgpu/jpeg: Remove harvest checking for JPEG3
drm/amdgpu/gfx: disable gfx9 cp_ecc_error_irq only when enabling legacy gfx ras
drm/amd/pm: avoid potential UBSAN issue on legacy asics
drm/i915: taint kernel when force probing unsupported devices
drm/i915/dp: prevent potential div-by-zero
drm/i915: Fix NULL ptr deref by checking new_crtc_state
drm/i915/guc: Don't capture Gen8 regs on Xe devices
drm/amdgpu: disable sdma ecc irq only when sdma RAS is enabled in suspend
drm/amdgpu: Fix vram recover doesn't work after whole GPU reset (v2)
drm/amdgpu: drop gfx_v11_0_cp_ecc_error_irq_funcs
drm/amd/display: Enforce 60us prefetch for 200Mhz DCFCLK modes
drm/amd/display: Add symclk workaround during disable link output
drm/amd/pm: parse pp_handle under appropriate conditions
drm/amdgpu: set gfx9 onwards APU atomics support to be true
drm/amdgpu/nv: update VCN 3 max HEVC encoding resolution
drm/sched: Check scheduler work queue before calling timeout handling
drm/mipi-dsi: Set the fwnode for mipi_dsi_device
drm/nouveau/disp: More DP_RECEIVER_CAP_SIZE array fixes
drm/dsc: fix DP_DSC_MAX_BPP_DELTA_* macro values
...
Linus Torvalds [Thu, 11 May 2023 21:51:11 +0000 (16:51 -0500)]
Merge tag 'xfs-6.4-rc1-fixes' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs bug fixes from Dave Chinner:
"Largely minor bug fixes and cleanups, th emost important of which are
probably the fixes for regressions in the extent allocation code:
- fixes for inode garbage collection shutdown racing with work queue
updates
- ensure inodegc workers run on the CPU they are supposed to
- disable counter scrubbing until we can exclusively freeze the
filesystem from the kernel
- regression fixes for new allocation related bugs
- a couple of minor cleanups"
* tag 'xfs-6.4-rc1-fixes' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: fix xfs_inodegc_stop racing with mod_delayed_work
xfs: disable reaping in fscounters scrub
xfs: check that per-cpu inodegc workers actually run on that cpu
xfs: explicitly specify cpu when forcing inodegc delayed work to run immediately
xfs: fix negative array access in xfs_getbmap
xfs: don't allocate into the data fork for an unshare request
xfs: flush dirty data and drain directios before scrubbing cow fork
xfs: set bnobt/cntbt numrecs correctly when formatting new AGs
xfs: don't unconditionally null args->pag in xfs_bmap_btalloc_at_eof
Zheng Wang [Thu, 27 Apr 2023 03:08:41 +0000 (11:08 +0800)]
fbdev: imsttfb: Fix use after free bug in imsttfb_probe
A use-after-free bug may occur if init_imstt invokes framebuffer_release
and free the info ptr. The caller, imsttfb_probe didn't notice that and
still keep the ptr as private data in pdev.
If we remove the driver which will call imsttfb_remove to make cleanup,
UAF happens.
Fix it by return error code if bad case happens in init_imstt.
Signed-off-by: Zheng Wang <zyytlz.wz@163.com> Signed-off-by: Helge Deller <deller@gmx.de>
Dave Airlie [Thu, 11 May 2023 19:32:36 +0000 (05:32 +1000)]
Merge tag 'drm-misc-fixes-2023-05-11' of git://anongit.freedesktop.org/drm/drm-misc into drm-fixes
drm-misc-fixes for v6.4-rc2:
- More DSC macro fixes.
- Small mipi-dsi fix.
- Scheduler timeout handling fix.
---
drm-misc-fixes for v6.4-rc1:
- Fix DSC macros.
- Fix VESA format for simplefb.
- Prohibit potential out-of-bounds access in generic fbdev emulation.
- Improve AST2500+ compat on ARM.
Linus Torvalds [Thu, 11 May 2023 14:01:40 +0000 (09:01 -0500)]
Merge tag 'dt-fixes-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux-dt
Pull devicetree binding fixes from Krzysztof Kozlowski:
"A few fixes for Devicetree bindings and related docs, all for issues
introduced in v6.4-rc1 commits:
- media/ov2685: fix number of possible data lanes, as old binding
explicitly mentioned one data lane. This fixes dt_binding_check
warnings like:
Documentation/devicetree/bindings/media/rockchip-isp1.example.dtb: camera@3c: port:endpoint:data-lanes: [[1]] is too short
From schema: Documentation/devicetree/bindings/media/i2c/ovti,ov2685.yaml
- PCI/fsl,imx6q: correct parsing of assigned-clocks and related
properties and make the clocks more specific per PCI device (host
or endpoint). This fixes dtschema limitation and dt_binding_check
warnings like:
Documentation/devicetree/bindings/pci/fsl,imx6q-pcie-ep.example.dtb: pcie-ep@33800000: Unevaluated properties are not allowed
From schema: Documentation/devicetree/bindings/pci/fsl,imx6q-pcie-ep.yaml
- Maintainers: correct path of Apple PWM binding. This fixes
refcheckdocs warning"
* tag 'dt-fixes-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux-dt:
dt-bindings: PCI: fsl,imx6q: fix assigned-clocks warning
MAINTAINERS: adjust file entry for ARM/APPLE MACHINE SUPPORT
media: dt-bindings: ov2685: Correct data-lanes attribute
Linus Torvalds [Thu, 11 May 2023 13:42:47 +0000 (08:42 -0500)]
Merge tag 'net-6.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
"Including fixes from netfilter.
Current release - regressions:
- mtk_eth_soc: fix NULL pointer dereference
Previous releases - regressions:
- core:
- skb_partial_csum_set() fix against transport header magic value
- fix load-tearing on sk->sk_stamp in sock_recv_cmsgs().
- annotate sk->sk_err write from do_recvmmsg()
- add vlan_get_protocol_and_depth() helper
- netlink: annotate accesses to nlk->cb_running
- netfilter: always release netdev hooks from notifier
Previous releases - always broken:
- core: deal with most data-races in sk_wait_event()
- netfilter: fix possible bug_on with enable_hooks=1
- eth: bonding: fix send_peer_notif overflow
- eth: xpcs: fix incorrect number of interfaces
- eth: ipvlan: fix out-of-bounds caused by unclear skb->cb
* tag 'net-6.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (31 commits)
af_unix: Fix data races around sk->sk_shutdown.
af_unix: Fix a data race of sk->sk_receive_queue->qlen.
net: datagram: fix data-races in datagram_poll()
net: mscc: ocelot: fix stat counter register values
ipvlan:Fix out-of-bounds caused by unclear skb->cb
docs: networking: fix x25-iface.rst heading & index order
gve: Remove the code of clearing PBA bit
tcp: add annotations around sk->sk_shutdown accesses
net: add vlan_get_protocol_and_depth() helper
net: pcs: xpcs: fix incorrect number of interfaces
net: deal with most data-races in sk_wait_event()
net: annotate sk->sk_err write from do_recvmmsg()
netlink: annotate accesses to nlk->cb_running
kselftest: bonding: add num_grat_arp test
selftests: forwarding: lib: add netns support for tc rule handle stats get
Documentation: bonding: fix the doc of peer_notif_delay
bonding: fix send_peer_notif overflow
net: ethernet: mtk_eth_soc: fix NULL pointer dereference
selftests: nft_flowtable.sh: check ingress/egress chain too
selftests: nft_flowtable.sh: monitor result file sizes
...
Zongjie Li [Tue, 9 May 2023 11:27:26 +0000 (19:27 +0800)]
fbdev: arcfb: Fix error handling in arcfb_probe()
Smatch complains that:
arcfb_probe() warn: 'irq' from request_irq() not released on lines: 587.
Fix error handling in the arcfb_probe() function. If IO addresses are
not provided or framebuffer registration fails, the code will jump to
the err_addr or err_register_fb label to release resources.
If IRQ request fails, previously allocated resources will be freed.
Fixes: 1154ea7dcd8e ("[PATCH] Framebuffer driver for Arc LCD board") Signed-off-by: Zongjie Li <u202112089@hust.edu.cn> Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn> Signed-off-by: Helge Deller <deller@gmx.de>
Yifan Zhang [Wed, 10 May 2023 08:13:48 +0000 (16:13 +0800)]
drm/amdgpu: change gfx 11.0.4 external_id range
gfx 11.0.4 range starts from 0x80.
Fixes: 311d52367d0a ("drm/amdgpu: add soc21 common ip block support for GC 11.0.4") Cc: stable@vger.kernel.org Signed-off-by: Yifan Zhang <yifan1.zhang@amd.com> Reported-by: Yogesh Mohan Marimuthu <Yogesh.Mohanmarimuthu@amd.com> Acked-by: Alex Deucher <alexander.deucher@amd.com> Reviewed-by: Tim Huang <Tim.Huang@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Guchun Chen [Sat, 6 May 2023 12:06:45 +0000 (20:06 +0800)]
drm/amdgpu/gfx: disable gfx9 cp_ecc_error_irq only when enabling legacy gfx ras
gfx9 cp_ecc_error_irq is only enabled when legacy gfx ras is assert.
So in gfx_v9_0_hw_fini, interrupt disablement for cp_ecc_error_irq
should be executed under such condition, otherwise, an amdgpu_irq_put
calltrace will occur.
Jani Nikula [Thu, 4 May 2023 10:35:08 +0000 (13:35 +0300)]
drm/i915: taint kernel when force probing unsupported devices
For development and testing purposes, the i915.force_probe module
parameter and DRM_I915_FORCE_PROBE kconfig option allow probing of
devices that aren't supported by the driver.
The i915.force_probe module parameter is "unsafe" and setting it taints
the kernel. However, using the kconfig option does not.
Always taint the kernel when force probing a device that is not
supported.
v2: Drop "depends on EXPERT" to avoid build breakage (kernel test robot)
Fixes: 7ef5ef5cdead ("drm/i915: add force_probe module parameter to replace alpha_support") Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Dave Airlie <airlied@gmail.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20230504103508.1818540-1-jani.nikula@intel.com
(cherry picked from commit 3312bb4ad09ca6423bd4a5b15a94588a8962fb8e) Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
drm_dp_dsc_sink_max_slice_count() may return 0 if something goes
wrong on the part of the DSC sink and its DPCD register. This null
value may be later used as a divisor in intel_dsc_compute_params(),
which will lead to an error.
In the unlikely event that this issue occurs, fix it by testing the
return value of drm_dp_dsc_sink_max_slice_count() against zero.
Found by Linux Verification Center (linuxtesting.org) with static
analysis tool SVACE.