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.
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.
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:
ACPI: APEI: send SIGBUS to current task if synchronous memory error not recovered
If a synchronous error is detected as a result of user-space process
triggering a 2-bit uncorrected error, the CPU will take a synchronous
error exception such as Synchronous External Abort (SEA) on Arm64. The
kernel will queue a memory_failure() work which poisons the related
page, unmaps the page, and then sends a SIGBUS to the process, so that
a system wide panic can be avoided.
However, no memory_failure() work will be queued when abnormal
synchronous errors occur. These errors can include situations like
invalid PA, unexpected severity, no memory failure config support,
invalid GUID section, etc. In such a case, the user-space process will
trigger SEA again. This loop can potentially exceed the platform
firmware threshold or even trigger a kernel hard lockup, leading to a
system reboot.
Fix it by performing a force kill if no memory_failure() work is queued
for synchronous errors.
[ rjw: Changelog edits ]