Bug 2420253 (CVE-2023-53786)

Summary: CVE-2023-53786 kernel: dm flakey: fix a crash with invalid table line
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was identified in the device-mapper “dm flakey” target in the Linux kernel where invalid table line input can lead to a NULL pointer dereference. Specifically, when dmsetup is used with a malformed table line (such as with the corrupt_bio_byte target) and the arg_name pointer is NULL, the kernel attempts to dereference it, leading to a system crash (kernel panic). This is due to insufficient validation of input arguments before use
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Description OSIDB Bzimport 2025-12-09 01:03:29 UTC 
In the Linux kernel, the following vulnerability has been resolved:

dm flakey: fix a crash with invalid table line

This command will crash with NULL pointer dereference:
 dmsetup create flakey --table \
  "0 `blockdev --getsize /dev/ram0` flakey /dev/ram0 0 0 1 2 corrupt_bio_byte 512"

Fix the crash by checking if arg_name is non-NULL before comparing it.
Comment 1 Alexander B 2025-12-10 06:58:48 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025120940-CVE-2023-53786-3c1a@gregkh/T