CVE-2026-43410

Published May 8, 2026

Last updated 5 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: firmware: stratix10-rsu: Fix NULL pointer dereference when RSU is disabled When the Remote System Update (RSU) isn't enabled in the First Stage Boot Loader (FSBL), the driver encounters a NULL pointer dereference when excute svc_normal_to_secure_thread() thread, resulting in a kernel panic: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 Mem abort info: ... Data abort info: ... [0000000000000008] user address but active_mm is swapper Internal error: Oops: 0000000096000004 [#1] SMP Modules linked in: CPU: 0 UID: 0 PID: 79 Comm: svc_smc_hvc_thr Not tainted 6.19.0-rc8-yocto-standard+ #59 PREEMPT Hardware name: SoCFPGA Stratix 10 SoCDK (DT) pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : svc_normal_to_secure_thread+0x38c/0x990 lr : svc_normal_to_secure_thread+0x144/0x990 ... Call trace: svc_normal_to_secure_thread+0x38c/0x990 (P) kthread+0x150/0x210 ret_from_fork+0x10/0x20 Code: 97cfc113 f9400260 aa1403e1 f9400400 (f9400402) ---[ end trace 0000000000000000 ]--- The issue occurs because rsu_send_async_msg() fails when RSU is not enabled in firmware, causing the channel to be freed via stratix10_svc_free_channel(). However, the probe function continues execution and registers svc_normal_to_secure_thread(), which subsequently attempts to access the already-freed channel, triggering the NULL pointer dereference. Fix this by properly cleaning up the async client and returning early on failure, preventing the thread from being used with an invalid channel.
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
CWE-476

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