PT-2025-14367 · Linux+5 · Linux Kernel+5
Published
2025-03-05
·
Updated
2026-05-26
·
CVE-2025-21986
CVSS v3.1
5.5
Medium
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Name of the Vulnerable Software and Affected Versions
Linux kernel versions prior to the fixed version
Description
A vulnerability in the Linux kernel's switchdev notification chain has been resolved. The issue involved a blocking notification chain that used a read-write semaphore to protect the chain's integrity. However, recursive notifications were possible, leading to the semaphore being acquired twice for reading and generating lockdep warnings. This could happen when the bridge driver processed a SWITCHDEV BRPORT UNOFFLOADED event, causing it to emit notifications about deferred events. The fix converted the notification chain to a raw notification chain, protecting it using the RTNL mutex.
Recommendations
For Linux kernel versions prior to the fixed version, consider applying the patch that converts the blocking notification chain to a raw notification chain to resolve the issue. As a temporary workaround, consider restricting access to the switchdev notification chain to minimize the risk of exploitation.
Exploit
Fix
DoS
Improper Locking
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Related Identifiers
Affected Products
Astra Linux
Debian
Linuxmint
Linux Kernel
Red Os
Ubuntu