CVE-2026-43277

Published May 6, 2026

Last updated 6 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: APEI/GHES: ensure that won't go past CPER allocated record The logic at ghes_new() prevents allocating too large records, by checking if they're bigger than GHES_ESTATUS_MAX_SIZE (currently, 64KB). Yet, the allocation is done with the actual number of pages from the CPER bios table location, which can be smaller. Yet, a bad firmware could send data with a different size, which might be bigger than the allocated memory, causing an OOPS: Unable to handle kernel paging request at virtual address fff00000f9b40000 Mem abort info: ESR = 0x0000000096000007 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x07: level 3 translation fault Data abort info: ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 swapper pgtable: 4k pages, 52-bit VAs, pgdp=000000008ba16000 [fff00000f9b40000] pgd=180000013ffff403, p4d=180000013fffe403, pud=180000013f85b403, pmd=180000013f68d403, pte=0000000000000000 Internal error: Oops: 0000000096000007 [#1] SMP Modules linked in: CPU: 0 UID: 0 PID: 303 Comm: kworker/0:1 Not tainted 6.19.0-rc1-00002-gda407d200220 #34 PREEMPT Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 02/02/2022 Workqueue: kacpi_notify acpi_os_execute_deferred pstate: 214020c5 (nzCv daIF +PAN -UAO -TCO +DIT -SSBS BTYPE=--) pc : hex_dump_to_buffer+0x30c/0x4a0 lr : hex_dump_to_buffer+0x328/0x4a0 sp : ffff800080e13880 x29: ffff800080e13880 x28: ffffac9aba86f6a8 x27: 0000000000000083 x26: fff00000f9b3fffc x25: 0000000000000004 x24: 0000000000000004 x23: ffff800080e13905 x22: 0000000000000010 x21: 0000000000000083 x20: 0000000000000001 x19: 0000000000000008 x18: 0000000000000010 x17: 0000000000000001 x16: 00000007c7f20fec x15: 0000000000000020 x14: 0000000000000008 x13: 0000000000081020 x12: 0000000000000008 x11: ffff800080e13905 x10: ffff800080e13988 x9 : 0000000000000000 x8 : 0000000000000000 x7 : 0000000000000001 x6 : 0000000000000020 x5 : 0000000000000030 x4 : 00000000fffffffe x3 : 0000000000000000 x2 : ffffac9aba78c1c8 x1 : ffffac9aba76d0a8 x0 : 0000000000000008 Call trace: hex_dump_to_buffer+0x30c/0x4a0 (P) print_hex_dump+0xac/0x170 cper_estatus_print_section+0x90c/0x968 cper_estatus_print+0xf0/0x158 __ghes_print_estatus+0xa0/0x148 ghes_proc+0x1bc/0x220 ghes_notify_hed+0x5c/0xb8 notifier_call_chain+0x78/0x148 blocking_notifier_call_chain+0x4c/0x80 acpi_hed_notify+0x28/0x40 acpi_ev_notify_dispatch+0x50/0x80 acpi_os_execute_deferred+0x24/0x48 process_one_work+0x15c/0x3b0 worker_thread+0x2d0/0x400 kthread+0x148/0x228 ret_from_fork+0x10/0x20 Code: 6b14033f 540001ad a94707e2 f100029f (b8747b44) ---[ end trace 0000000000000000 ]--- Prevent that by taking the actual allocated are into account when checking for CPER length. [ rjw: Subject tweaks ]
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
NVD-CWE-noinfo

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