| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/riscv: prevent NULL deref in iova_to_phys
The riscv_iommu_pte_fetch() function returns either NULL for
unmapped/never-mapped iova, or a valid leaf pte pointer that
requires no further validation.
riscv_iommu_iova_to_phys() failed to handle NULL returns.
Prevent null pointer dereference in
riscv_iommu_iova_to_phys(), and remove the pte validation. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ath12k: Correct tid cleanup when tid setup fails
Currently, if any error occurs during ath12k_dp_rx_peer_tid_setup(),
the tid value is already incremented, even though the corresponding
TID is not actually allocated. Proceed to
ath12k_dp_rx_peer_tid_delete() starting from unallocated tid,
which might leads to freeing unallocated TID and cause potential
crash or out-of-bounds access.
Hence, fix by correctly decrementing tid before cleanup to match only
the successfully allocated TIDs.
Also, remove tid-- from failure case of ath12k_dp_rx_peer_frag_setup(),
as decrementing the tid before cleanup in loop will take care of this.
Compile tested only. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/migrate: don't overflow max copy size
With non-page aligned copy, we need to use 4 byte aligned pitch, however
the size itself might still be close to our maximum of ~8M, and so the
dimensions of the copy can easily exceed the S16_MAX limit of the copy
command leading to the following assert:
xe 0000:03:00.0: [drm] Assertion `size / pitch <= ((s16)(((u16)~0U) >> 1))` failed!
platform: BATTLEMAGE subplatform: 1
graphics: Xe2_HPG 20.01 step A0
media: Xe2_HPM 13.01 step A1
tile: 0 VRAM 10.0 GiB
GT: 0 type 1
WARNING: CPU: 23 PID: 10605 at drivers/gpu/drm/xe/xe_migrate.c:673 emit_copy+0x4b5/0x4e0 [xe]
To fix this account for the pitch when calculating the number of current
bytes to copy.
(cherry picked from commit 8c2d61e0e916e077fda7e7b8e67f25ffe0f361fc) |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/migrate: prevent potential UAF
If we hit the error path, the previous fence (if there is one) has
already been put() prior to this, so doing a fence_wait could lead to
UAF. Tweak the flow to do to the put() until after we do the wait.
(cherry picked from commit 9b7ca35ed28fe5fad86e9d9c24ebd1271e4c9c3e) |
| In the Linux kernel, the following vulnerability has been resolved:
mm/vmscan: fix hwpoisoned large folio handling in shrink_folio_list
In shrink_folio_list(), the hwpoisoned folio may be large folio, which
can't be handled by unmap_poisoned_folio(). For THP, try_to_unmap_one()
must be passed with TTU_SPLIT_HUGE_PMD to split huge PMD first and then
retry. Without TTU_SPLIT_HUGE_PMD, we will trigger null-ptr deref of
pvmw.pte. Even we passed TTU_SPLIT_HUGE_PMD, we will trigger a
WARN_ON_ONCE due to the page isn't in swapcache.
Since UCE is rare in real world, and race with reclaimation is more rare,
just skipping the hwpoisoned large folio is enough. memory_failure() will
handle it if the UCE is triggered again.
This happens when memory reclaim for large folio races with
memory_failure(), and will lead to kernel panic. The race is as
follows:
cpu0 cpu1
shrink_folio_list memory_failure
TestSetPageHWPoison
unmap_poisoned_folio
--> trigger BUG_ON due to
unmap_poisoned_folio couldn't
handle large folio
[tujinjiang@huawei.com: add comment to unmap_poisoned_folio()] |
| In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix unbuffered write error handling
If all the subrequests in an unbuffered write stream fail, the subrequest
collector doesn't update the stream->transferred value and it retains its
initial LONG_MAX value. Unfortunately, if all active streams fail, then we
take the smallest value of { LONG_MAX, LONG_MAX, ... } as the value to set
in wreq->transferred - which is then returned from ->write_iter().
LONG_MAX was chosen as the initial value so that all the streams can be
quickly assessed by taking the smallest value of all stream->transferred -
but this only works if we've set any of them.
Fix this by adding a flag to indicate whether the value in
stream->transferred is valid and checking that when we integrate the
values. stream->transferred can then be initialised to zero.
This was found by running the generic/750 xfstest against cifs with
cache=none. It splices data to the target file. Once (if) it has used up
all the available scratch space, the writes start failing with ENOSPC.
This causes ->write_iter() to fail. However, it was returning
wreq->transferred, i.e. LONG_MAX, rather than an error (because it thought
the amount transferred was non-zero) and iter_file_splice_write() would
then try to clean up that amount of pipe bufferage - leading to an oops
when it overran. The kernel log showed:
CIFS: VFS: Send error in write = -28
followed by:
BUG: kernel NULL pointer dereference, address: 0000000000000008
with:
RIP: 0010:iter_file_splice_write+0x3a4/0x520
do_splice+0x197/0x4e0
or:
RIP: 0010:pipe_buf_release (include/linux/pipe_fs_i.h:282)
iter_file_splice_write (fs/splice.c:755)
Also put a warning check into splice to announce if ->write_iter() returned
that it had written more than it was asked to. |
| In the Linux kernel, the following vulnerability has been resolved:
media: mt9m114: Fix deadlock in get_frame_interval/set_frame_interval
Getting / Setting the frame interval using the V4L2 subdev pad ops
get_frame_interval/set_frame_interval causes a deadlock, as the
subdev state is locked in the [1] but also in the driver itself.
In [2] it's described that the caller is responsible to acquire and
release the lock in this case. Therefore, acquiring the lock in the
driver is wrong.
Remove the lock acquisitions/releases from mt9m114_ifp_get_frame_interval()
and mt9m114_ifp_set_frame_interval().
[1] drivers/media/v4l2-core/v4l2-subdev.c - line 1129
[2] Documentation/driver-api/media/v4l2-subdev.rst |
| In the Linux kernel, the following vulnerability has been resolved:
drm/mcde: Fix refcount leak in mcde_dsi_bind
Every iteration of for_each_available_child_of_node() decrements
the reference counter of the previous node. There is no decrement
when break out from the loop and results in refcount leak.
Add missing of_node_put() to fix this. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: ctnetlink: remove refcounting in expectation dumpers
Same pattern as previous patch: do not keep the expectation object
alive via refcount, only store a cookie value and then use that
as the skip hint for dump resumption.
AFAICS this has the same issue as the one resolved in the conntrack
dumper, when we do
if (!refcount_inc_not_zero(&exp->use))
to increment the refcount, there is a chance that exp == last, which
causes a double-increment of the refcount and subsequent memory leak. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: timer: fix ida_free call while not allocated
In the snd_utimer_create() function, if the kasprintf() function return
NULL, snd_utimer_put_id() will be called, finally use ida_free()
to free the unallocated id 0.
the syzkaller reported the following information:
------------[ cut here ]------------
ida_free called for id=0 which is not allocated.
WARNING: CPU: 1 PID: 1286 at lib/idr.c:592 ida_free+0x1fd/0x2f0 lib/idr.c:592
Modules linked in:
CPU: 1 UID: 0 PID: 1286 Comm: syz-executor164 Not tainted 6.15.8 #3 PREEMPT(lazy)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-4.fc42 04/01/2014
RIP: 0010:ida_free+0x1fd/0x2f0 lib/idr.c:592
Code: f8 fc 41 83 fc 3e 76 69 e8 70 b2 f8 (...)
RSP: 0018:ffffc900007f79c8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 1ffff920000fef3b RCX: ffffffff872176a5
RDX: ffff88800369d200 RSI: 0000000000000000 RDI: ffff88800369d200
RBP: 0000000000000000 R08: ffffffff87ba60a5 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f6f1abc1740(0000) GS:ffff8880d76a0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6f1ad7a784 CR3: 000000007a6e2000 CR4: 00000000000006f0
Call Trace:
<TASK>
snd_utimer_put_id sound/core/timer.c:2043 [inline] [snd_timer]
snd_utimer_create+0x59b/0x6a0 sound/core/timer.c:2184 [snd_timer]
snd_utimer_ioctl_create sound/core/timer.c:2202 [inline] [snd_timer]
__snd_timer_user_ioctl.isra.0+0x724/0x1340 sound/core/timer.c:2287 [snd_timer]
snd_timer_user_ioctl+0x75/0xc0 sound/core/timer.c:2298 [snd_timer]
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl fs/ioctl.c:893 [inline]
__x64_sys_ioctl+0x198/0x200 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x7b/0x160 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
[...]
The utimer->id should be set properly before the kasprintf() function,
ensures the snd_utimer_put_id() function will free the allocated id. |
| In the Linux kernel, the following vulnerability has been resolved:
LoongArch: Optimize module load time by optimizing PLT/GOT counting
When enabling CONFIG_KASAN, CONFIG_PREEMPT_VOLUNTARY_BUILD and
CONFIG_PREEMPT_VOLUNTARY at the same time, there will be soft deadlock,
the relevant logs are as follows:
rcu: INFO: rcu_sched self-detected stall on CPU
...
Call Trace:
[<900000000024f9e4>] show_stack+0x5c/0x180
[<90000000002482f4>] dump_stack_lvl+0x94/0xbc
[<9000000000224544>] rcu_dump_cpu_stacks+0x1fc/0x280
[<900000000037ac80>] rcu_sched_clock_irq+0x720/0xf88
[<9000000000396c34>] update_process_times+0xb4/0x150
[<90000000003b2474>] tick_nohz_handler+0xf4/0x250
[<9000000000397e28>] __hrtimer_run_queues+0x1d0/0x428
[<9000000000399b2c>] hrtimer_interrupt+0x214/0x538
[<9000000000253634>] constant_timer_interrupt+0x64/0x80
[<9000000000349938>] __handle_irq_event_percpu+0x78/0x1a0
[<9000000000349a78>] handle_irq_event_percpu+0x18/0x88
[<9000000000354c00>] handle_percpu_irq+0x90/0xf0
[<9000000000348c74>] handle_irq_desc+0x94/0xb8
[<9000000001012b28>] handle_cpu_irq+0x68/0xa0
[<9000000001def8c0>] handle_loongarch_irq+0x30/0x48
[<9000000001def958>] do_vint+0x80/0xd0
[<9000000000268a0c>] kasan_mem_to_shadow.part.0+0x2c/0x2a0
[<90000000006344f4>] __asan_load8+0x4c/0x120
[<900000000025c0d0>] module_frob_arch_sections+0x5c8/0x6b8
[<90000000003895f0>] load_module+0x9e0/0x2958
[<900000000038b770>] __do_sys_init_module+0x208/0x2d0
[<9000000001df0c34>] do_syscall+0x94/0x190
[<900000000024d6fc>] handle_syscall+0xbc/0x158
After analysis, this is because the slow speed of loading the amdgpu
module leads to the long time occupation of the cpu and then the soft
deadlock.
When loading a module, module_frob_arch_sections() tries to figure out
the number of PLTs/GOTs that will be needed to handle all the RELAs. It
will call the count_max_entries() to find in an out-of-order date which
counting algorithm has O(n^2) complexity.
To make it faster, we sort the relocation list by info and addend. That
way, to check for a duplicate relocation, it just needs to compare with
the previous entry. This reduces the complexity of the algorithm to O(n
log n), as done in commit d4e0340919fb ("arm64/module: Optimize module
load time by optimizing PLT counting"). This gives sinificant reduction
in module load time for modules with large number of relocations.
After applying this patch, the soft deadlock problem has been solved,
and the kernel starts normally without "Call Trace".
Using the default configuration to test some modules, the results are as
follows:
Module Size
ip_tables 36K
fat 143K
radeon 2.5MB
amdgpu 16MB
Without this patch:
Module Module load time (ms) Count(PLTs/GOTs)
ip_tables 18 59/6
fat 0 162/14
radeon 54 1221/84
amdgpu 1411 4525/1098
With this patch:
Module Module load time (ms) Count(PLTs/GOTs)
ip_tables 18 59/6
fat 0 162/14
radeon 22 1221/84
amdgpu 45 4525/1098 |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: HWS, fix complex rules rehash error flow
Moving rules from matcher to matcher should not fail.
However, if it does fail due to various reasons, the error flow
should allow the kernel to continue functioning (albeit with broken
steering rules) instead of going into series of soft lock-ups or
some other problematic behaviour.
Similar to the simple rules, complex rules rehash logic suffers
from the same problems. This patch fixes the error flow for moving
complex rules:
- If new rule creation fails before it was even enqeued, do not
poll for completion
- If TIMEOUT happened while moving the rule, no point trying
to poll for completions for other rules. Something is broken,
completion won't come, just abort the rehash sequence.
- If some other completion with error received, don't give up.
Continue handling rest of the rules to minimize the damage.
- Make sure that the first error code that was received will
be actually returned to the caller instead of replacing it
with the generic error code.
All the aforementioned issues stem from the same bad error flow,
so no point fixing them one by one and leaving partially broken
code - fixing them in one patch. |
| In the Linux kernel, the following vulnerability has been resolved:
bnxt_en: Fix lockdep warning during rmmod
The commit under the Fixes tag added a netdev_assert_locked() in
bnxt_free_ntp_fltrs(). The lock should be held during normal run-time
but the assert will be triggered (see below) during bnxt_remove_one()
which should not need the lock. The netdev is already unregistered by
then. Fix it by calling netdev_assert_locked_or_invisible() which will
not assert if the netdev is unregistered.
WARNING: CPU: 5 PID: 2241 at ./include/net/netdev_lock.h:17 bnxt_free_ntp_fltrs+0xf8/0x100 [bnxt_en]
Modules linked in: rpcrdma rdma_cm iw_cm ib_cm configfs ib_core bnxt_en(-) bridge stp llc x86_pkg_temp_thermal xfs tg3 [last unloaded: bnxt_re]
CPU: 5 UID: 0 PID: 2241 Comm: rmmod Tainted: G S W 6.16.0 #2 PREEMPT(voluntary)
Tainted: [S]=CPU_OUT_OF_SPEC, [W]=WARN
Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.4.3 01/17/2017
RIP: 0010:bnxt_free_ntp_fltrs+0xf8/0x100 [bnxt_en]
Code: 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 8b 47 60 be ff ff ff ff 48 8d b8 28 0c 00 00 e8 d0 cf 41 c3 85 c0 0f 85 2e ff ff ff <0f> 0b e9 27 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffa92082387da0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff9e5b593d8000 RCX: 0000000000000001
RDX: 0000000000000001 RSI: ffffffff83dc9a70 RDI: ffffffff83e1a1cf
RBP: ffff9e5b593d8c80 R08: 0000000000000000 R09: ffffffff8373a2b3
R10: 000000008100009f R11: 0000000000000001 R12: 0000000000000001
R13: ffffffffc01c4478 R14: dead000000000122 R15: dead000000000100
FS: 00007f3a8a52c740(0000) GS:ffff9e631ad1c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055bb289419c8 CR3: 000000011274e001 CR4: 00000000003706f0
Call Trace:
<TASK>
bnxt_remove_one+0x57/0x180 [bnxt_en]
pci_device_remove+0x39/0xc0
device_release_driver_internal+0xa5/0x130
driver_detach+0x42/0x90
bus_remove_driver+0x61/0xc0
pci_unregister_driver+0x38/0x90
bnxt_exit+0xc/0x7d0 [bnxt_en] |
| In the Linux kernel, the following vulnerability has been resolved:
regulator: pca9450: Use devm_register_sys_off_handler
With module test, there is error dump:
------------[ cut here ]------------
notifier callback pca9450_i2c_restart_handler already registered
WARNING: kernel/notifier.c:23 at notifier_chain_register+0x5c/0x88,
CPU#0: kworker/u16:3/50
Call trace:
notifier_chain_register+0x5c/0x88 (P)
atomic_notifier_chain_register+0x30/0x58
register_restart_handler+0x1c/0x28
pca9450_i2c_probe+0x418/0x538
i2c_device_probe+0x220/0x3d0
really_probe+0x114/0x410
__driver_probe_device+0xa0/0x150
driver_probe_device+0x40/0x114
__device_attach_driver+0xd4/0x12c
So use devm_register_sys_off_handler to let kernel handle the resource
free to avoid kernel dump. |
| In the Linux kernel, the following vulnerability has been resolved:
iio: adc: rzg2l_adc: Set driver data before enabling runtime PM
When stress-testing the system by repeatedly unbinding and binding the ADC
device in a loop, and the ADC is a supplier for another device (e.g., a
thermal hardware block that reads temperature through the ADC), it may
happen that the ADC device is runtime-resumed immediately after runtime PM
is enabled, triggered by its consumer. At this point, since drvdata is not
yet set and the driver's runtime PM callbacks rely on it, a crash can
occur. To avoid this, set drvdata just after it was allocated. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/mremap: fix WARN with uffd that has remap events disabled
Registering userfaultd on a VMA that spans at least one PMD and then
mremap()'ing that VMA can trigger a WARN when recovering from a failed
page table move due to a page table allocation error.
The code ends up doing the right thing (recurse, avoiding moving actual
page tables), but triggering that WARN is unpleasant:
WARNING: CPU: 2 PID: 6133 at mm/mremap.c:357 move_normal_pmd mm/mremap.c:357 [inline]
WARNING: CPU: 2 PID: 6133 at mm/mremap.c:357 move_pgt_entry mm/mremap.c:595 [inline]
WARNING: CPU: 2 PID: 6133 at mm/mremap.c:357 move_page_tables+0x3832/0x44a0 mm/mremap.c:852
Modules linked in:
CPU: 2 UID: 0 PID: 6133 Comm: syz.0.19 Not tainted 6.17.0-rc1-syzkaller-00004-g53e760d89498 #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:move_normal_pmd mm/mremap.c:357 [inline]
RIP: 0010:move_pgt_entry mm/mremap.c:595 [inline]
RIP: 0010:move_page_tables+0x3832/0x44a0 mm/mremap.c:852
Code: ...
RSP: 0018:ffffc900037a76d8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000032930007 RCX: ffffffff820c6645
RDX: ffff88802e56a440 RSI: ffffffff820c7201 RDI: 0000000000000007
RBP: ffff888037728fc0 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000032930007 R11: 0000000000000000 R12: 0000000000000000
R13: ffffc900037a79a8 R14: 0000000000000001 R15: dffffc0000000000
FS: 000055556316a500(0000) GS:ffff8880d68bc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30863fff CR3: 0000000050171000 CR4: 0000000000352ef0
Call Trace:
<TASK>
copy_vma_and_data+0x468/0x790 mm/mremap.c:1215
move_vma+0x548/0x1780 mm/mremap.c:1282
mremap_to+0x1b7/0x450 mm/mremap.c:1406
do_mremap+0xfad/0x1f80 mm/mremap.c:1921
__do_sys_mremap+0x119/0x170 mm/mremap.c:1977
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f00d0b8ebe9
Code: ...
RSP: 002b:00007ffe5ea5ee98 EFLAGS: 00000246 ORIG_RAX: 0000000000000019
RAX: ffffffffffffffda RBX: 00007f00d0db5fa0 RCX: 00007f00d0b8ebe9
RDX: 0000000000400000 RSI: 0000000000c00000 RDI: 0000200000000000
RBP: 00007ffe5ea5eef0 R08: 0000200000c00000 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000002
R13: 00007f00d0db5fa0 R14: 00007f00d0db5fa0 R15: 0000000000000005
</TASK>
The underlying issue is that we recurse during the original page table
move, but not during the recovery move.
Fix it by checking for both VMAs and performing the check before the
pmd_none() sanity check.
Add a new helper where we perform+document that check for the PMD and PUD
level.
Thanks to Harry for bisecting. |
| Twonky Server 8.5.2 on Linux and Windows is vulnerable to a cryptographic flaw, use of hard-coded cryptographic keys. An attacker with knowledge of the encrypted administrator password can decrypt the value with static keys to view the plain text password and gain administrator-level access to Twonky Server. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: acomp - Fix CFI failure due to type punning
To avoid a crash when control flow integrity is enabled, make the
workspace ("stream") free function use a consistent type, and call it
through a function pointer that has that same type. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: subpage: keep TOWRITE tag until folio is cleaned
btrfs_subpage_set_writeback() calls folio_start_writeback() the first time
a folio is written back, and it also clears the PAGECACHE_TAG_TOWRITE tag
even if there are still dirty blocks in the folio. This can break ordering
guarantees, such as those required by btrfs_wait_ordered_extents().
That ordering breakage leads to a real failure. For example, running
generic/464 on a zoned setup will hit the following ASSERT. This happens
because the broken ordering fails to flush existing dirty pages before the
file size is truncated.
assertion failed: !list_empty(&ordered->list) :: 0, in fs/btrfs/zoned.c:1899
------------[ cut here ]------------
kernel BUG at fs/btrfs/zoned.c:1899!
Oops: invalid opcode: 0000 [#1] SMP NOPTI
CPU: 2 UID: 0 PID: 1906169 Comm: kworker/u130:2 Kdump: loaded Not tainted 6.16.0-rc6-BTRFS-ZNS+ #554 PREEMPT(voluntary)
Hardware name: Supermicro Super Server/H12SSL-NT, BIOS 2.0 02/22/2021
Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
RIP: 0010:btrfs_finish_ordered_zoned.cold+0x50/0x52 [btrfs]
RSP: 0018:ffffc9002efdbd60 EFLAGS: 00010246
RAX: 000000000000004c RBX: ffff88811923c4e0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff827e38b1 RDI: 00000000ffffffff
RBP: ffff88810005d000 R08: 00000000ffffdfff R09: ffffffff831051c8
R10: ffffffff83055220 R11: 0000000000000000 R12: ffff8881c2458c00
R13: ffff88811923c540 R14: ffff88811923c5e8 R15: ffff8881c1bd9680
FS: 0000000000000000(0000) GS:ffff88a04acd0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f907c7a918c CR3: 0000000004024000 CR4: 0000000000350ef0
Call Trace:
<TASK>
? srso_return_thunk+0x5/0x5f
btrfs_finish_ordered_io+0x4a/0x60 [btrfs]
btrfs_work_helper+0xf9/0x490 [btrfs]
process_one_work+0x204/0x590
? srso_return_thunk+0x5/0x5f
worker_thread+0x1d6/0x3d0
? __pfx_worker_thread+0x10/0x10
kthread+0x118/0x230
? __pfx_kthread+0x10/0x10
ret_from_fork+0x205/0x260
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Consider process A calling writepages() with WB_SYNC_NONE. In zoned mode or
for compressed writes, it locks several folios for delalloc and starts
writing them out. Let's call the last locked folio folio X. Suppose the
write range only partially covers folio X, leaving some pages dirty.
Process A calls btrfs_subpage_set_writeback() when building a bio. This
function call clears the TOWRITE tag of folio X, whose size = 8K and
the block size = 4K. It is following state.
0 4K 8K
|/////|/////| (flag: DIRTY, tag: DIRTY)
<-----> Process A will write this range.
Now suppose process B concurrently calls writepages() with WB_SYNC_ALL. It
calls tag_pages_for_writeback() to tag dirty folios with
PAGECACHE_TAG_TOWRITE. Since folio X is still dirty, it gets tagged. Then,
B collects tagged folios using filemap_get_folios_tag() and must wait for
folio X to be written before returning from writepages().
0 4K 8K
|/////|/////| (flag: DIRTY, tag: DIRTY|TOWRITE)
However, between tagging and collecting, process A may call
btrfs_subpage_set_writeback() and clear folio X's TOWRITE tag.
0 4K 8K
| |/////| (flag: DIRTY|WRITEBACK, tag: DIRTY)
As a result, process B won't see folio X in its batch, and returns without
waiting for it. This breaks the WB_SYNC_ALL ordering requirement.
Fix this by using btrfs_subpage_set_writeback_keepwrite(), which retains
the TOWRITE tag. We now manually clear the tag only after the folio becomes
clean, via the xas operation. |
| In the Linux kernel, the following vulnerability has been resolved:
sched/ext: Fix invalid task state transitions on class switch
When enabling a sched_ext scheduler, we may trigger invalid task state
transitions, resulting in warnings like the following (which can be
easily reproduced by running the hotplug selftest in a loop):
sched_ext: Invalid task state transition 0 -> 3 for fish[770]
WARNING: CPU: 18 PID: 787 at kernel/sched/ext.c:3862 scx_set_task_state+0x7c/0xc0
...
RIP: 0010:scx_set_task_state+0x7c/0xc0
...
Call Trace:
<TASK>
scx_enable_task+0x11f/0x2e0
switching_to_scx+0x24/0x110
scx_enable.isra.0+0xd14/0x13d0
bpf_struct_ops_link_create+0x136/0x1a0
__sys_bpf+0x1edd/0x2c30
__x64_sys_bpf+0x21/0x30
do_syscall_64+0xbb/0x370
entry_SYSCALL_64_after_hwframe+0x77/0x7f
This happens because we skip initialization for tasks that are already
dead (with their usage counter set to zero), but we don't exclude them
during the scheduling class transition phase.
Fix this by also skipping dead tasks during class swiching, preventing
invalid task state transitions. |
