VulnerabilityPublished 8 May 2026Updated 6 Nov 2026

CVE-2026-43292: Linux kernel · mm/vmalloc: prevent RCU stalls in kasan_release_vmalloc_node

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in b351fbe71091f7c8676c8ba597653d08b6719447 : update Linux kernel when convenient.

Data as of 6 Nov 2026, 16:04 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in b351fbe71091f7c8676c8ba597653d08b6719447, 5747435e0fd474c24530ef1a6822f47e7d264b27, 2efa9c02c9b4c0d6866aa445f11056809b25ca28 +1

Exploitation evidence

Disclosed: evidence found.
CVE published 8 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Linux kernel to b351fbe71091f7c8676c8ba597653d08b6719447, 5747435e0fd474c24530ef1a6822f47e7d264b27, 2efa9c02c9b4c0d6866aa445f11056809b25ca28 or 1afe45f89d54b7183768ebbbbf14238ec187ab5c.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 282631cb2447318e2a55b41a665dbe8571c46d70, < b351fbe71091f7c8676c8ba597653d08b6719447	Fixed in b351fbe71091f7c8676c8ba597653d08b6719447
LinuxLinux	Affected ≥ 282631cb2447318e2a55b41a665dbe8571c46d70, < 5747435e0fd474c24530ef1a6822f47e7d264b27	Fixed in 5747435e0fd474c24530ef1a6822f47e7d264b27
LinuxLinux	Affected ≥ 282631cb2447318e2a55b41a665dbe8571c46d70, < 2efa9c02c9b4c0d6866aa445f11056809b25ca28	Fixed in 2efa9c02c9b4c0d6866aa445f11056809b25ca28
LinuxLinux	Affected ≥ 282631cb2447318e2a55b41a665dbe8571c46d70, < 1afe45f89d54b7183768ebbbbf14238ec187ab5c	Fixed in 1afe45f89d54b7183768ebbbbf14238ec187ab5c
LinuxLinux	Affected =6.9	Fixed in–

Description

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

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