CVE-2026-23469

Published Apr 3, 2026

Last updated 3 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: drm/imagination: Synchronize interrupts before suspending the GPU The runtime PM suspend callback doesn't know whether the IRQ handler is in progress on a different CPU core and doesn't wait for it to finish. Depending on timing, the IRQ handler could be running while the GPU is suspended, leading to kernel crashes when trying to access GPU registers. See example signature below. In a power off sequence initiated by the runtime PM suspend callback, wait for any IRQ handlers in progress on other CPU cores to finish, by calling synchronize_irq(). At the same time, remove the runtime PM resume/put calls in the threaded IRQ handler. On top of not being the right approach to begin with, and being at the wrong place as they should have wrapped all GPU register accesses, the driver would hit a deadlock between synchronize_irq() being called from a runtime PM suspend callback, holding the device power lock, and the resume callback requiring the same. Example crash signature on a TI AM68 SK platform: [ 337.241218] SError Interrupt on CPU0, code 0x00000000bf000000 -- SError [ 337.241239] CPU: 0 UID: 0 PID: 112 Comm: irq/234-gpu Tainted: G M 6.17.7-B2C-00005-g9c7bbe4ea16c #2 PREEMPT [ 337.241246] Tainted: [M]=MACHINE_CHECK [ 337.241249] Hardware name: Texas Instruments AM68 SK (DT) [ 337.241252] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 337.241256] pc : pvr_riscv_irq_pending+0xc/0x24 [ 337.241277] lr : pvr_device_irq_thread_handler+0x64/0x310 [ 337.241282] sp : ffff800085b0bd30 [ 337.241284] x29: ffff800085b0bd50 x28: ffff0008070d9eab x27: ffff800083a5ce10 [ 337.241291] x26: ffff000806e48f80 x25: ffff0008070d9eac x24: 0000000000000000 [ 337.241296] x23: ffff0008068e9bf0 x22: ffff0008068e9bd0 x21: ffff800085b0bd30 [ 337.241301] x20: ffff0008070d9e00 x19: ffff0008068e9000 x18: 0000000000000001 [ 337.241305] x17: 637365645f656c70 x16: 0000000000000000 x15: ffff000b7df9ff40 [ 337.241310] x14: 0000a585fe3c0d0e x13: 000000999704f060 x12: 000000000002771a [ 337.241314] x11: 00000000000000c0 x10: 0000000000000af0 x9 : ffff800085b0bd00 [ 337.241318] x8 : ffff0008071175d0 x7 : 000000000000b955 x6 : 0000000000000003 [ 337.241323] x5 : 0000000000000000 x4 : 0000000000000002 x3 : 0000000000000000 [ 337.241327] x2 : ffff800080e39d20 x1 : ffff800080e3fc48 x0 : 0000000000000000 [ 337.241333] Kernel panic - not syncing: Asynchronous SError Interrupt [ 337.241337] CPU: 0 UID: 0 PID: 112 Comm: irq/234-gpu Tainted: G M 6.17.7-B2C-00005-g9c7bbe4ea16c #2 PREEMPT [ 337.241342] Tainted: [M]=MACHINE_CHECK [ 337.241343] Hardware name: Texas Instruments AM68 SK (DT) [ 337.241345] Call trace: [ 337.241348] show_stack+0x18/0x24 (C) [ 337.241357] dump_stack_lvl+0x60/0x80 [ 337.241364] dump_stack+0x18/0x24 [ 337.241368] vpanic+0x124/0x2ec [ 337.241373] abort+0x0/0x4 [ 337.241377] add_taint+0x0/0xbc [ 337.241384] arm64_serror_panic+0x70/0x80 [ 337.241389] do_serror+0x3c/0x74 [ 337.241392] el1h_64_error_handler+0x30/0x48 [ 337.241400] el1h_64_error+0x6c/0x70 [ 337.241404] pvr_riscv_irq_pending+0xc/0x24 (P) [ 337.241410] irq_thread_fn+0x2c/0xb0 [ 337.241416] irq_thread+0x170/0x334 [ 337.241421] kthread+0x12c/0x210 [ 337.241428] ret_from_fork+0x10/0x20 [ 337.241434] SMP: stopping secondary CPUs [ 337.241451] Kernel Offset: disabled [ 337.241453] CPU features: 0x040000,02002800,20002001,0400421b [ 337.241456] Memory Limit: none [ 337.457921] ---[ end Kernel panic - not syncing: Asynchronous SError Interrupt ]---
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Modified
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
4.7
Impact score
3.6
Exploitability score
1
Vector string
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
CWE-362

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: cgroup: Avoid iteration of dying tasks with zero refcount The commit 260fbcb92bbea ("cgroup: Move dying_tasks cleanup from cgroup_task_release() to cgroup_task_free()") extended the lifetime of tasks on the dying_tasks list. The iterators have provision to go through dying_tasks because of dying threadgroup leaders or explicit CSS_TASK_ITER_WITH_DEAD, however, it was expected that such tasks can obtain a new reference (that is possible before cgroup_task_release()/put_task_struct_rcu_user()). The tasks after cgroup_task_release() and before cgroup_task_free() are subject to race when they may or may not have ->usage count > 0. The race window is between css_task_iter_next() invocations when css_set_lock is released and we may arrive at a new ->task_pos. The iterator should not attempt to resurrect tasks whose ->usage count dropped to zero. (When that happens, __put_task_struct_rcu_cb() is already imminent and the returned task_struct would could be used after free.) As for the fix, we cannot simply check the signal->live count of a task on the dying list because that won't distinguish regular zombies waiting to be reaped from RCU remnant tasks that are going to be free'd. Therefore add an extra check to rule out ->usage==0 tasks from any iteration. The repeat: loop in css_task_iter_advance() doesn't consider ->usage count, so add a new loop to css_task_iter_next() to skip de-used tasks on the dying_list. Rough illustration of the possible race R (reader of cgroup.procs) T (thread) L (group leader) --------------------------------- -------------------------------- -------------------------------- L exits, signal->live > 0 cgroup_task_dead(L) css_set_skip_task_iters() // skips only cset->tasks list_add_tail(&L->cg_list, &cset->dying_tasks) css_task_iter_next() take css_set_lock css_task_iter_advance() leader && signal->live != 0 => it->task_pos = &L->cg_list release css_set_lock T exits --signal->live == 0 cgroup_task_dead(T) // css_set_lock release_task(T) cgroup_task_release(T) release_task(L) // zap_leader cgroup_task_release(L) put_task_struct_rcu_user(L) ...RCU... put_task_struct(L) L->usage = 0 /* L still on dying_tasks */ ...RCU... __put_task_struct(L) css_task_iter_next() // another iteration take css_set_lock it->task_pos = &L->cg_list get_task_struct(L) => addition on 0 drop css_set_lock cgroup_task_free(L) css_set_skip_task_iters() // dying skip comes too late free_task(L) cgroup_procs_show() task_pid_vnr(L)•CVE-2026-98163