CVE-2024-40925

CVE Details

Release Date:

2024-07-12

Description

In the Linux kernel, the following vulnerability has been resolved:\nblock: fix request.queuelist usage in flush\nFriedrich Weber reported a kernel crash problem and bisected to commit\n81ada09cc25e ('blk-flush: reuse rq queuelist in flush state machine').\nThe root cause is that we use 'list_move_tail(&rq->queuelist, pending)'\nin the PREFLUSH/POSTFLUSH sequences. But rq->queuelist.next == xxx since\nit's popped out from plug->cached_rq in __blk_mq_alloc_requests_batch().\nWe don't initialize its queuelist just for this first request, although\nthe queuelist of all later popped requests will be initialized.\nFix it by changing to use 'list_add_tail(&rq->queuelist, pending)' so\nrq->queuelist doesn't need to be initialized. It should be ok since rq\ncan't be on any list when PREFLUSH or POSTFLUSH, has no move actually.\nPlease note the commit 81ada09cc25e ('blk-flush: reuse rq queuelist in\nflush state machine') also has another requirement that no drivers would\ntouch rq->queuelist after blk_mq_end_request() since we will reuse it to\nadd rq to the post-flush pending list in POSTFLUSH. If this is not true,\nwe will have to revert that commit IMHO.\nThis updated version adds 'list_del_init(&rq->queuelist)' in flush rq\ncallback since the dm layer may submit request of a weird invalid format\n(REQ_FSEQ_PREFLUSH | REQ_FSEQ_POSTFLUSH), which causes double list_add\nif without this 'list_del_init(&rq->queuelist)'. The weird invalid format\nproblem should be fixed in dm layer.

See more information about CVE-2024-40925 from MITRE CVE dictionary and NIST NVD

CVSS Scoring

NOTE: The following CVSS v3.1 metrics and score provided are preliminary and subject to review.

Base Score:	5.5	CVSS Vector:	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector:	Local network	Attack Complexity:	Low
Privileges Required:	Low	User Interaction:	None
Scope:	Unchanged	Confidentiality Impact:	None
Integrity Impact:	None	Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 9 (kernel)	ELSA-2024-9315	2024-11-14