Upstream information
Description
In the Linux kernel, the following vulnerability has been resolved:ublk: fix deadlock when reading partition table
When one process(such as udev) opens ublk block device (e.g., to read
the partition table via bdev_open()), a deadlock[1] can occur:
1. bdev_open() grabs disk->open_mutex
2. The process issues read I/O to ublk backend to read partition table
3. In __ublk_complete_rq(), blk_update_request() or blk_mq_end_request()
runs bio->bi_end_io() callbacks
4. If this triggers fput() on file descriptor of ublk block device, the
work may be deferred to current task's task work (see fput() implementation)
5. This eventually calls blkdev_release() from the same context
6. blkdev_release() tries to grab disk->open_mutex again
7. Deadlock: same task waiting for a mutex it already holds
The fix is to run blk_update_request() and blk_mq_end_request() with bottom
halves disabled. This forces blkdev_release() to run in kernel work-queue
context instead of current task work context, and allows ublk server to make
forward progress, and avoids the deadlock.
[axboe: rewrite comment in ublk]
SUSE information
Overall state of this security issue: Does not affect SUSE products
SUSE Bugzilla entry: 1256652 [NEW] No SUSE Security Announcements cross referenced.SUSE Timeline for this CVE
CVE page created: Wed Jan 14 14:49:58 2026CVE page last modified: Wed Jan 14 14:49:58 2026