{"cve":"CVE-2024-50140","nvd":{"published":"2024-11-07T10:15:05.980","modified":"2026-06-17T08:03:41.480","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched/core: Disable page allocation in task_tick_mm_cid()\n\nWith KASAN and PREEMPT_RT enabled, calling task_work_add() in\ntask_tick_mm_cid() may cause the following splat.\n\n[   63.696416] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48\n[   63.696416] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 610, name: modprobe\n[   63.696416] preempt_count: 10001, expected: 0\n[   63.696416] RCU nest depth: 1, expected: 1\n\nThis problem is caused by the following call trace.\n\n  sched_tick() [ acquire rq->__lock ]\n   -> task_tick_mm_cid()\n    -> task_work_add()\n     -> __kasan_record_aux_stack()\n      -> kasan_save_stack()\n       -> stack_depot_save_flags()\n        -> alloc_pages_mpol_noprof()\n         -> __alloc_pages_noprof()\n\t  -> get_page_from_freelist()\n\t   -> rmqueue()\n\t    -> rmqueue_pcplist()\n\t     -> __rmqueue_pcplist()\n\t      -> rmqueue_bulk()\n\t       -> rt_spin_lock()\n\nThe rq lock is a raw_spinlock_t. We can't sleep while holding\nit. IOW, we can't call alloc_pages() in stack_depot_save_flags().\n\nThe task_tick_mm_cid() function with its task_work_add() call was\nintroduced by commit 223baf9d17f2 (\"sched: Fix performance regression\nintroduced by mm_cid\") in v6.4 kernel.\n\nFortunately, there is a kasan_record_aux_stack_noalloc() variant that\ncalls stack_depot_save_flags() while not allowing it to allocate\nnew pages.  To allow task_tick_mm_cid() to use task_work without\npage allocation, a new TWAF_NO_ALLOC flag is added to enable calling\nkasan_record_aux_stack_noalloc() instead of kasan_record_aux_stack()\nif set. The task_tick_mm_cid() function is modified to add this new flag.\n\nThe possible downside is the missing stack trace in a KASAN report due\nto new page allocation required when task_work_add_noallloc() is called\nwhich should be rare.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/509c29d0d26f68a6f6d0a05cb1a89725237e2b87","https://git.kernel.org/stable/c/73ab05aa46b02d96509cb029a8d04fca7bbde8c7","https://git.kernel.org/stable/c/ce0241ef83eed55f675376e8a3605d23de53d875"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:57:07.693694550+00:00"},"epss":{"cve":"CVE-2024-50140","score":0.00231,"percentile":0.14015,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}