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]
References
Configurations
Configuration 1 (hide)
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History
26 Feb 2026, 18:43
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:* |
|
| CWE | CWE-667 | |
| References | () https://git.kernel.org/stable/c/0460e09a614291f06c008443f47393c37b7358e7 - Patch | |
| References | () https://git.kernel.org/stable/c/64c0b7e2293757e8320f13434cd809f1c9257a62 - Patch | |
| References | () https://git.kernel.org/stable/c/9bcc47343ee0ef346aa7b2b460c8ff56bd882fe7 - Patch | |
| References | () https://git.kernel.org/stable/c/c258f5c4502c9667bccf5d76fa731ab9c96687c1 - Patch | |
| First Time |
Linux
Linux linux Kernel |
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
12 Feb 2026, 09:16
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
13 Jan 2026, 16:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-01-13 16:16
Updated : 2026-02-26 18:43
NVD link : CVE-2025-68823
Mitre link : CVE-2025-68823
CVE.ORG link : CVE-2025-68823
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-667
Improper Locking
