Bug 2424869 (CVE-2025-68348)

Summary: CVE-2025-68348 kernel: Linux kernel: Memory leak in block subsystem can lead to denial of service
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedKeywords: Security
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel. A local user could trigger a memory leak in the `__blkdev_issue_zero_pages` function within the block subsystem. This occurs when a fatal signal is pending and a block I/O (bio) is allocated but not properly freed, leading to resource exhaustion. This vulnerability can result in a Denial of Service (DoS).
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2025-12-24 11:02:20 UTC 
In the Linux kernel, the following vulnerability has been resolved:

block: fix memory leak in __blkdev_issue_zero_pages

Move the fatal signal check before bio_alloc() to prevent a memory
leak when BLKDEV_ZERO_KILLABLE is set and a fatal signal is pending.

Previously, the bio was allocated before checking for a fatal signal.
If a signal was pending, the code would break out of the loop without
freeing or chaining the just-allocated bio, causing a memory leak.

This matches the pattern already used in __blkdev_issue_write_zeroes()
where the signal check precedes the allocation.
Comment 1 Alexander B 2025-12-25 16:36:51 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025122453-CVE-2025-68348-2088@gregkh/T