- Description
- 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.
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- NVD status
- Analyzed
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
- Hype score
- Not currently trending
CVE-2024-50140 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_tic... https://t.co/Q3yvDAvOtb
@VulmonFeeds
7 Nov 2024
57 Impressions
1 Retweet
1 Like
1 Bookmark
0 Replies
0 Quotes
CVE-2024-50140 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, cal… https://t.co/GDfEz7P2Rm
@CVEnew
7 Nov 2024
466 Impressions
0 Retweets
0 Likes
0 Bookmarks
0 Replies
0 Quotes
[
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "F0663E1D-0BCE-4D24-BFE4-F9C52687DD40",
"versionEndExcluding": "6.6.59",
"versionStartIncluding": "6.4"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E4486B12-007B-4794-9857-F07145637AA1",
"versionEndExcluding": "6.11.6",
"versionStartIncluding": "6.7"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "7F361E1D-580F-4A2D-A509-7615F73167A1"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.12:rc2:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "925478D0-3E3D-4E6F-ACD5-09F28D5DF82C"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.12:rc3:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "3C95E234-D335-4B6C-96BF-E2CEBD8654ED"
}
],
"operator": "OR"
}
]
}
]