cbcvebase.
CVE-2025-68823
published 2026-01-13

CVE-2025-68823: 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…

PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.12%
2.1th percentile
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]

Affected

45 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.18.3-1 (forky)linux 6.18.3-1 (forky)
linuxlinux
linuxlinux>= 71f28f3136aff5890cd56de78abc673f8393cad9 < 27bb79b7717b2fbb111a1c13548b2786ee712dca27bb79b7717b2fbb111a1c13548b2786ee712dca
linuxlinux>= 71f28f3136aff5890cd56de78abc673f8393cad9 < 64c0b7e2293757e8320f13434cd809f1c9257a6264c0b7e2293757e8320f13434cd809f1c9257a62
linuxlinux>= 71f28f3136aff5890cd56de78abc673f8393cad9 < 9bcc47343ee0ef346aa7b2b460c8ff56bd882fe79bcc47343ee0ef346aa7b2b460c8ff56bd882fe7
linuxlinux>= 71f28f3136aff5890cd56de78abc673f8393cad9 < 0460e09a614291f06c008443f47393c37b7358e70460e09a614291f06c008443f47393c37b7358e7
linuxlinux>= 71f28f3136aff5890cd56de78abc673f8393cad9 < c258f5c4502c9667bccf5d76fa731ab9c96687c1c258f5c4502c9667bccf5d76fa731ab9c96687c1
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.12.73-16.12.73-1
linuxlinux_kernel>= 0 < 6.18.3-16.18.3-1
linuxlinux_kernel>= 6.0 < 6.6.1246.6.124
linuxlinux_kernel>= 6.13 < 6.18.36.18.3
linuxlinux_kernel>= 6.7 < 6.12.706.12.70
ubuntulinux
ubuntulinux-aws
ubuntulinux-aws-6.17
ubuntulinux-aws-fips
ubuntulinux-azure
ubuntulinux-azure-6.17
ubuntulinux-azure-6.8
ubuntulinux-azure-fips
ubuntulinux-fips
ubuntulinux-gcp
ubuntulinux-gcp-6.17
ubuntulinux-gcp-fips

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_ubuntu7.8HIGH
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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