Bug 2400627 (CVE-2025-39926) - CVE-2025-39926 kernel: genetlink: fix genl_bind() invoking bind() after -EPERM
Summary: CVE-2025-39926 kernel: genetlink: fix genl_bind() invoking bind() after -EPERM
Keywords:
Status: NEW
Alias: CVE-2025-39926
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-10-01 09:01 UTC by OSIDB Bzimport
Modified: 2025-10-02 11:36 UTC (History)
0 users

Fixed In Version:
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Description OSIDB Bzimport 2025-10-01 09:01:42 UTC
In the Linux kernel, the following vulnerability has been resolved:

genetlink: fix genl_bind() invoking bind() after -EPERM

Per family bind/unbind callbacks were introduced to allow families
to track multicast group consumer presence, e.g. to start or stop
producing events depending on listeners.

However, in genl_bind() the bind() callback was invoked even if
capability checks failed and ret was set to -EPERM. This means that
callbacks could run on behalf of unauthorized callers while the
syscall still returned failure to user space.

Fix this by only invoking bind() after "if (ret) break;" check
i.e. after permission checks have succeeded.


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