In the Linux kernel, the following vulnerability has been resolved:
mm/vmalloc: prevent RCU stalls in kasan_release_vmalloc_node
When CONFIG_PAGE_OWNER is enabled, freeing KASAN shadow pages during
vmalloc cleanup triggers expensive stack unwinding that acquires RCU read
locks. Processing a large purge_list without rescheduling can cause the
task to hold CPU for extended periods (10+ seconds), leading to RCU stalls
and potential OOM conditions.
The issue manifests in purge_vmap_node() -> kasan_release_vmalloc_node()
where iterating through hundreds or thousands of vmap_area entries and
freeing their associated shadow pages causes:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6229/1:b..l
...
task:kworker/0:17 state:R running task stack:28840 pid:6229
...
kasan_release_vmalloc_node+0x1ba/0xad0 mm/vmalloc.c:2299
purge_vmap_node+0x1ba/0xad0 mm/vmalloc.c:2299
Each call to kasan_release_vmalloc() can free many pages, and with
page_owner tracking, each free triggers save_stack() which performs stack
unwinding under RCU read lock. Without yielding, this creates an
unbounded RCU critical section.
Add periodic cond_resched() calls within the loop to allow:
- RCU grace periods to complete
- Other tasks to run
- Scheduler to preempt when needed
The fix uses need_resched() for immediate response under load, with a
batch count of 32 as a guaranteed upper bound to prevent worst-case stalls
even under light load.
References
Configurations
Configuration 1 (hide)
|
History
14 May 2026, 21:04
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Linux linux Kernel
Linux |
|
| CWE | NVD-CWE-noinfo | |
| References | () https://git.kernel.org/stable/c/1afe45f89d54b7183768ebbbbf14238ec187ab5c - Patch | |
| References | () https://git.kernel.org/stable/c/2efa9c02c9b4c0d6866aa445f11056809b25ca28 - Patch | |
| References | () https://git.kernel.org/stable/c/5747435e0fd474c24530ef1a6822f47e7d264b27 - Patch | |
| References | () https://git.kernel.org/stable/c/b351fbe71091f7c8676c8ba597653d08b6719447 - Patch | |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
08 May 2026, 14:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-08 14:16
Updated : 2026-05-14 21:04
NVD link : CVE-2026-43292
Mitre link : CVE-2026-43292
CVE.ORG link : CVE-2026-43292
JSON object : View
Products Affected
linux
- linux_kernel
CWE