CVE-2025-68823

MEDIUM EPSS 2.1%
Published Jan 13, 20265mo ago · Modified Jun 17, 20262w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Jan 13, 2026 5mo ago
Last Modified Jun 17, 2026 2w ago

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]

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
2.1% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-667

Affected Products 4

VendorProductVersionRange
linuxlinux_kernel*≥6.0  –  <6.6.124
linuxlinux_kernel*≥6.7  –  <6.12.70
linuxlinux_kernel*≥6.13  –  <6.18.3
linuxlinux_kernel6.19any

References 5

  • git.kernel.org https://git.kernel.org/stable/c/0460e09a614291f06c008443f47393c37b7358e7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/27bb79b7717b2fbb111a1c13548b2786ee712dca
  • git.kernel.org https://git.kernel.org/stable/c/64c0b7e2293757e8320f13434cd809f1c9257a62
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9bcc47343ee0ef346aa7b2b460c8ff56bd882fe7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c258f5c4502c9667bccf5d76fa731ab9c96687c1
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/0460e09a614291f06c008443f47393c37b7358e7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/64c0b7e2293757e8320f13434cd809f1c9257a62
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9bcc47343ee0ef346aa7b2b460c8ff56bd882fe7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c258f5c4502c9667bccf5d76fa731ab9c96687c1
    Patch