In the Linux kernel, the following vulnerability has been resolved:
dmaengine: idxd: Check availability of workqueue allocated by idxd wq driver before using
Running IDXD workloads in a container with the /dev directory mounted can
trigger a call trace or even a kernel panic when the parent process of the
container is terminated.
This issue occurs because, under certain configurations, Docker does not
properly propagate the mount replica back to the original mount point.
In this case, when the user driver detaches, the WQ is destroyed but it
still calls destroy_workqueue() attempting to completes all pending work.
It's necessary to check wq->wq and skip the drain if it no longer exists.
In the Linux kernel, the following vulnerability has been resolved:
drm/msm/gpu: Fix crash when throttling GPU immediately during boot
There is a small chance that the GPU is already hot during boot. In that
case, the call to of_devfreq_cooling_register() will immediately try to
apply devfreq cooling, as seen in the following crash:
Unable to handle kernel paging request at virtual address 0000000000014110
pc : a6xx_gpu_busy+0x1c/0x58 [msm]
lr : msm_devfreq_get_dev_status+0xbc/0x140 [msm]
Call trace:
a6xx_gpu_busy+0x1c/0x58 [msm] (P)
devfreq_simple_ondemand_func+0x3c/0x150
devfreq_update_target+0x44/0xd8
qos_max_notifier_call+0x30/0x84
blocking_notifier_call_chain+0x6c/0xa0
pm_qos_update_target+0xd0/0x110
freq_qos_apply+0x3c/0x74
apply_constraint+0x88/0x148
__dev_pm_qos_update_request+0x7c/0xcc
dev_pm_qos_update_request+0x38/0x5c
devfreq_cooling_set_cur_state+0x98/0xf0
__thermal_cdev_update+0x64/0xb4
thermal_cdev_update+0x4c/0x58
step_wise_manage+0x1f0/0x318
__thermal_zone_device_update+0x278/0x424
__thermal_cooling_device_register+0x2bc/0x308
thermal_of_cooling_device_register+0x10/0x1c
of_devfreq_cooling_register_power+0x240/0x2bc
of_devfreq_cooling_register+0x14/0x20
msm_devfreq_init+0xc4/0x1a0 [msm]
msm_gpu_init+0x304/0x574 [msm]
adreno_gpu_init+0x1c4/0x2e0 [msm]
a6xx_gpu_init+0x5c8/0x9c8 [msm]
adreno_bind+0x2a8/0x33c [msm]
...
At this point we haven't initialized the GMU at all yet, so we cannot read
the GMU registers inside a6xx_gpu_busy(). A similar issue was fixed before
in commit 6694482a70e9 ("drm/msm: Avoid unclocked GMU register access in
6xx gpu_busy"): msm_devfreq_init() does call devfreq_suspend_device(), but
unlike msm_devfreq_suspend(), it doesn't set the df->suspended flag
accordingly. This means the df->suspended flag does not match the actual
devfreq state after initialization and msm_devfreq_get_dev_status() will
end up accessing GMU registers, causing the crash.
Fix this by setting df->suspended correctly during initialization.
Patchwork: https://patchwork.freedesktop.org/patch/650772/
In the Linux kernel, the following vulnerability has been resolved:
s390/mm: Fix in_atomic() handling in do_secure_storage_access()
Kernel user spaces accesses to not exported pages in atomic context
incorrectly try to resolve the page fault.
With debug options enabled call traces like this can be seen:
BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1523
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 419074, name: qemu-system-s39
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
INFO: lockdep is turned off.
Preemption disabled at:
[<00000383ea47cfa2>] copy_page_from_iter_atomic+0xa2/0x8a0
CPU: 12 UID: 0 PID: 419074 Comm: qemu-system-s39
Tainted: G W 6.16.0-20250531.rc0.git0.69b3a602feac.63.fc42.s390x+debug #1 PREEMPT
Tainted: [W]=WARN
Hardware name: IBM 3931 A01 703 (LPAR)
Call Trace:
[<00000383e990d282>] dump_stack_lvl+0xa2/0xe8
[<00000383e99bf152>] __might_resched+0x292/0x2d0
[<00000383eaa7c374>] down_read+0x34/0x2d0
[<00000383e99432f8>] do_secure_storage_access+0x108/0x360
[<00000383eaa724b0>] __do_pgm_check+0x130/0x220
[<00000383eaa842e4>] pgm_check_handler+0x114/0x160
[<00000383ea47d028>] copy_page_from_iter_atomic+0x128/0x8a0
([<00000383ea47d016>] copy_page_from_iter_atomic+0x116/0x8a0)
[<00000383e9c45eae>] generic_perform_write+0x16e/0x310
[<00000383e9eb87f4>] ext4_buffered_write_iter+0x84/0x160
[<00000383e9da0de4>] vfs_write+0x1c4/0x460
[<00000383e9da123c>] ksys_write+0x7c/0x100
[<00000383eaa7284e>] __do_syscall+0x15e/0x280
[<00000383eaa8417e>] system_call+0x6e/0x90
INFO: lockdep is turned off.
It is not allowed to take the mmap_lock while in atomic context. Therefore
handle such a secure storage access fault as if the accessed page is not
mapped: the uaccess function will return -EFAULT, and the caller has to
deal with this. Usually this means that the access is retried in process
context, which allows to resolve the page fault (or in this case export the
page).
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check dce_hwseq before dereferencing it
[WHAT]
hws was checked for null earlier in dce110_blank_stream, indicating hws
can be null, and should be checked whenever it is used.
(cherry picked from commit 79db43611ff61280b6de58ce1305e0b2ecf675ad)
In the Linux kernel, the following vulnerability has been resolved:
posix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del()
If an exiting non-autoreaping task has already passed exit_notify() and
calls handle_posix_cpu_timers() from IRQ, it can be reaped by its parent
or debugger right after unlock_task_sighand().
If a concurrent posix_cpu_timer_del() runs at that moment, it won't be
able to detect timer->it.cpu.firing != 0: cpu_timer_task_rcu() and/or
lock_task_sighand() will fail.
Add the tsk->exit_state check into run_posix_cpu_timers() to fix this.
This fix is not needed if CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y, because
exit_task_work() is called before exit_notify(). But the check still
makes sense, task_work_add(&tsk->posix_cputimers_work.work) will fail
anyway in this case.
In the Linux kernel, the following vulnerability has been resolved:
software node: Correct a OOB check in software_node_get_reference_args()
software_node_get_reference_args() wants to get @index-th element, so
the property value requires at least '(index + 1) * sizeof(*ref)' bytes
but that can not be guaranteed by current OOB check, and may cause OOB
for malformed property.
Fix by using as OOB check '((index + 1) * sizeof(*ref) > prop->length)'.
In the Linux kernel, the following vulnerability has been resolved:
ACPICA: fix acpi operand cache leak in dswstate.c
ACPICA commit 987a3b5cf7175916e2a4b6ea5b8e70f830dfe732
I found an ACPI cache leak in ACPI early termination and boot continuing case.
When early termination occurs due to malicious ACPI table, Linux kernel
terminates ACPI function and continues to boot process. While kernel terminates
ACPI function, kmem_cache_destroy() reports Acpi-Operand cache leak.
Boot log of ACPI operand cache leak is as follows:
>[ 0.585957] ACPI: Added _OSI(Module Device)
>[ 0.587218] ACPI: Added _OSI(Processor Device)
>[ 0.588530] ACPI: Added _OSI(3.0 _SCP Extensions)
>[ 0.589790] ACPI: Added _OSI(Processor Aggregator Device)
>[ 0.591534] ACPI Error: Illegal I/O port address/length above 64K: C806E00000004002/0x2 (20170303/hwvalid-155)
>[ 0.594351] ACPI Exception: AE_LIMIT, Unable to initialize fixed events (20170303/evevent-88)
>[ 0.597858] ACPI: Unable to start the ACPI Interpreter
>[ 0.599162] ACPI Error: Could not remove SCI handler (20170303/evmisc-281)
>[ 0.601836] kmem_cache_destroy Acpi-Operand: Slab cache still has objects
>[ 0.603556] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc5 #26
>[ 0.605159] Hardware name: innotek gmb_h virtual_box/virtual_box, BIOS virtual_box 12/01/2006
>[ 0.609177] Call Trace:
>[ 0.610063] ? dump_stack+0x5c/0x81
>[ 0.611118] ? kmem_cache_destroy+0x1aa/0x1c0
>[ 0.612632] ? acpi_sleep_proc_init+0x27/0x27
>[ 0.613906] ? acpi_os_delete_cache+0xa/0x10
>[ 0.617986] ? acpi_ut_delete_caches+0x3f/0x7b
>[ 0.619293] ? acpi_terminate+0xa/0x14
>[ 0.620394] ? acpi_init+0x2af/0x34f
>[ 0.621616] ? __class_create+0x4c/0x80
>[ 0.623412] ? video_setup+0x7f/0x7f
>[ 0.624585] ? acpi_sleep_proc_init+0x27/0x27
>[ 0.625861] ? do_one_initcall+0x4e/0x1a0
>[ 0.627513] ? kernel_init_freeable+0x19e/0x21f
>[ 0.628972] ? rest_init+0x80/0x80
>[ 0.630043] ? kernel_init+0xa/0x100
>[ 0.631084] ? ret_from_fork+0x25/0x30
>[ 0.633343] vgaarb: loaded
>[ 0.635036] EDAC MC: Ver: 3.0.0
>[ 0.638601] PCI: Probing PCI hardware
>[ 0.639833] PCI host bridge to bus 0000:00
>[ 0.641031] pci_bus 0000:00: root bus resource [io 0x0000-0xffff]
> ... Continue to boot and log is omitted ...
I analyzed this memory leak in detail and found acpi_ds_obj_stack_pop_and_
delete() function miscalculated the top of the stack. acpi_ds_obj_stack_push()
function uses walk_state->operand_index for start position of the top, but
acpi_ds_obj_stack_pop_and_delete() function considers index 0 for it.
Therefore, this causes acpi operand memory leak.
This cache leak causes a security threat because an old kernel (<= 4.9) shows
memory locations of kernel functions in stack dump. Some malicious users
could use this information to neutralize kernel ASLR.
I made a patch to fix ACPI operand cache leak.
In the Linux kernel, the following vulnerability has been resolved:
ftrace: Fix UAF when lookup kallsym after ftrace disabled
The following issue happens with a buggy module:
BUG: unable to handle page fault for address: ffffffffc05d0218
PGD 1bd66f067 P4D 1bd66f067 PUD 1bd671067 PMD 101808067 PTE 0
Oops: Oops: 0000 [#1] SMP KASAN PTI
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
RIP: 0010:sized_strscpy+0x81/0x2f0
RSP: 0018:ffff88812d76fa08 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffffc0601010 RCX: dffffc0000000000
RDX: 0000000000000038 RSI: dffffc0000000000 RDI: ffff88812608da2d
RBP: 8080808080808080 R08: ffff88812608da2d R09: ffff88812608da68
R10: ffff88812608d82d R11: ffff88812608d810 R12: 0000000000000038
R13: ffff88812608da2d R14: ffffffffc05d0218 R15: fefefefefefefeff
FS: 00007fef552de740(0000) GS:ffff8884251c7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffc05d0218 CR3: 00000001146f0000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ftrace_mod_get_kallsym+0x1ac/0x590
update_iter_mod+0x239/0x5b0
s_next+0x5b/0xa0
seq_read_iter+0x8c9/0x1070
seq_read+0x249/0x3b0
proc_reg_read+0x1b0/0x280
vfs_read+0x17f/0x920
ksys_read+0xf3/0x1c0
do_syscall_64+0x5f/0x2e0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The above issue may happen as follows:
(1) Add kprobe tracepoint;
(2) insmod test.ko;
(3) Module triggers ftrace disabled;
(4) rmmod test.ko;
(5) cat /proc/kallsyms; --> Will trigger UAF as test.ko already removed;
ftrace_mod_get_kallsym()
...
strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
...
The problem is when a module triggers an issue with ftrace and
sets ftrace_disable. The ftrace_disable is set when an anomaly is
discovered and to prevent any more damage, ftrace stops all text
modification. The issue that happened was that the ftrace_disable stops
more than just the text modification.
When a module is loaded, its init functions can also be traced. Because
kallsyms deletes the init functions after a module has loaded, ftrace
saves them when the module is loaded and function tracing is enabled. This
allows the output of the function trace to show the init function names
instead of just their raw memory addresses.
When a module is removed, ftrace_release_mod() is called, and if
ftrace_disable is set, it just returns without doing anything more. The
problem here is that it leaves the mod_list still around and if kallsyms
is called, it will call into this code and access the module memory that
has already been freed as it will return:
strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
Where the "mod" no longer exists and triggers a UAF bug.