CVE-2023-53531: In the Linux kernel, the following vulnerability has been resolved: null_blk: fix poll request timeout handling When doing io_uring benchmark on /dev/nullb0…

PriorityP420medium5.5CVSS 3.1

AVLACLPRLUINSUCNINAH

EPSS

0.14%

3.9th percentile

In the Linux kernel, the following vulnerability has been resolved: null_blk: fix poll request timeout handling When doing io_uring benchmark on /dev/nullb0, it's easy to crash the kernel if poll requests timeout triggered, as reported by David. [1] BUG: kernel NULL pointer dereference, address: 0000000000000008 Workqueue: kblockd blk_mq_timeout_work RIP: 0010:null_timeout_rq+0x4e/0x91 Call Trace: ? null_timeout_rq+0x4e/0x91 blk_mq_handle_expired+0x31/0x4b bt_iter+0x68/0x84 ? bt_tags_iter+0x81/0x81 __sbitmap_for_each_set.constprop.0+0xb0/0xf2 ? __blk_mq_complete_request_remote+0xf/0xf bt_for_each+0x46/0x64 ? __blk_mq_complete_request_remote+0xf/0xf ? percpu_ref_get_many+0xc/0x2a blk_mq_queue_tag_busy_iter+0x14d/0x18e blk_mq_timeout_work+0x95/0x127 process_one_work+0x185/0x263 worker_thread+0x1b5/0x227 This is indeed a race problem between null_timeout_rq() and null_poll(). null_poll() null_timeout_rq() spin_lock(&nq->poll_lock) list_splice_init(&nq->poll_list, &list) spin_unlock(&nq->poll_lock) while (!list_empty(&list)) req = list_first_entry() list_del_init() ... blk_mq_add_to_batch() // req->rq_next = NULL spin_lock(&nq->poll_lock) // rq->queuelist->next == NULL list_del_init(&rq->queuelist) spin_unlock(&nq->poll_lock) Fix these problems by setting requests state to MQ_RQ_COMPLETE under nq->poll_lock protection, in which null_timeout_rq() can safely detect this race and early return. Note this patch just fix the kernel panic when request timeout happen. [1] https://lore.kernel.org/all/[email protected]/

Affected

10 ranges

Vendor	Product	Version range	Fixed in
debian	linux	< linux 6.1.55-1 (bookworm)	linux 6.1.55-1 (bookworm)
linux	linux	—	—
linux	linux	>= 0a593fbbc245a85940ed34caa3aa1e4cb060c54b < a0b4a0666beacfe8add9c71d8922475541dbae73	a0b4a0666beacfe8add9c71d8922475541dbae73
linux	linux	>= 0a593fbbc245a85940ed34caa3aa1e4cb060c54b < a7cb2e709f2927cc3c76781df3e45de2381b3b9d	a7cb2e709f2927cc3c76781df3e45de2381b3b9d
linux	linux	>= 0a593fbbc245a85940ed34caa3aa1e4cb060c54b < 5a26e45edb4690d58406178b5a9ea4c6dcf2c105	5a26e45edb4690d58406178b5a9ea4c6dcf2c105
linux	linux_kernel	>= 0 < 6.1.55-1	6.1.55-1
linux	linux_kernel	>= 0 < 6.5.6-1	6.5.6-1
linux	linux_kernel	>= 0 < 6.5.6-1	6.5.6-1
linux	linux_kernel	>= 5.16 < 6.1.54	6.1.54
linux	linux_kernel	>= 6.2 < 6.5.4	6.5.4

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

osv5.5MEDIUM

vendor_debian5.5MEDIUM

vendor_redhat5.5MEDIUM

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