Bug 2363278 (CVE-2025-37759)

Summary: CVE-2025-37759 kernel: ublk: fix handling recovery & reissue in ublk_abort_queue()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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OS: Linux   
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Description OSIDB Bzimport 2025-05-01 14:01:52 UTC
In the Linux kernel, the following vulnerability has been resolved:

ublk: fix handling recovery & reissue in ublk_abort_queue()

Commit 8284066946e6 ("ublk: grab request reference when the request is handled
by userspace") doesn't grab request reference in case of recovery reissue.
Then the request can be requeued & re-dispatch & failed when canceling
uring command.

If it is one zc request, the request can be freed before io_uring
returns the zc buffer back, then cause kernel panic:

[  126.773061] BUG: kernel NULL pointer dereference, address: 00000000000000c8
[  126.773657] #PF: supervisor read access in kernel mode
[  126.774052] #PF: error_code(0x0000) - not-present page
[  126.774455] PGD 0 P4D 0
[  126.774698] Oops: Oops: 0000 [#1] SMP NOPTI
[  126.775034] CPU: 13 UID: 0 PID: 1612 Comm: kworker/u64:55 Not tainted 6.14.0_blk+ #182 PREEMPT(full)
[  126.775676] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 04/01/2014
[  126.776275] Workqueue: iou_exit io_ring_exit_work
[  126.776651] RIP: 0010:ublk_io_release+0x14/0x130 [ublk_drv]

Fixes it by always grabbing request reference for aborting the request.

Comment 1 Avinash Hanwate 2025-05-02 06:35:07 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025050140-CVE-2025-37759-5f57@gregkh/T