CVE-2024-50140
- Source
- https://cve.org/CVERecord?id=CVE-2024-50140
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-50140.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2024-50140
- Downstream
- Related
- Published
- 2024-11-07T09:31:17Z
- Modified
- 2026-08-12T03:30:35Z
- Severity
-
- 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- sched/core: Disable page allocation in task_tick_mm_cid()
- Details
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In the Linux kernel, the following vulnerability has been resolved:
sched/core: Disable page allocation in task_tick_mm_cid()
With KASAN and PREEMPT_RT enabled, calling task_work_add() in task_tick_mm_cid() may cause the following splat.
[ 63.696416] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 [ 63.696416] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 610, name: modprobe [ 63.696416] preempt_count: 10001, expected: 0 [ 63.696416] RCU nest depth: 1, expected: 1
This problem is caused by the following call trace.
sched_tick() [ acquire rq->__lock ] -> task_tick_mm_cid() -> task_work_add() -> __kasan_record_aux_stack() -> kasan_save_stack() -> stack_depot_save_flags() -> alloc_pages_mpol_noprof() -> __alloc_pages_noprof() -> get_page_from_freelist() -> rmqueue() -> rmqueue_pcplist() -> __rmqueue_pcplist() -> rmqueue_bulk() -> rt_spin_lock()
The rq lock is a raw_spinlock_t. We can't sleep while holding it. IOW, we can't call alloc_pages() in stack_depot_save_flags().
The task_tick_mm_cid() function with its task_work_add() call was introduced by commit 223baf9d17f2 ("sched: Fix performance regression introduced by mm_cid") in v6.4 kernel.
Fortunately, there is a kasan_record_aux_stack_noalloc() variant that calls stack_depot_save_flags() while not allowing it to allocate new pages. To allow task_tick_mm_cid() to use task_work without page allocation, a new TWAF_NO_ALLOC flag is added to enable calling kasan_record_aux_stack_noalloc() instead of kasan_record_aux_stack() if set. The task_tick_mm_cid() function is modified to add this new flag.
The possible downside is the missing stack trace in a KASAN report due to new page allocation required when task_work_add_noallloc() is called which should be rare.
- Database specific
{ "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/50xxx/CVE-2024-50140.json" }- References
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- https://git.kernel.org/stable/c/509c29d0d26f68a6f6d0a05cb1a89725237e2b87
- https://git.kernel.org/stable/c/73ab05aa46b02d96509cb029a8d04fca7bbde8c7
- https://git.kernel.org/stable/c/ce0241ef83eed55f675376e8a3605d23de53d875
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/50xxx/CVE-2024-50140.json
- https://nvd.nist.gov/vuln/detail/CVE-2024-50140
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git