CRITICAL · 9.8

CVE-2026-43376

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free by using call_rcu() for oplock_info ksmbd currently frees oplock_info immediately using kfree(), even th...

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free by using call_rcu() for oplock_info ksmbd currently frees oplock_info immediately using kfree(), even though it is accessed under RCU read-side critical sections in places like opinfo_get() and proc_show_files(). Since there is no RCU grace period delay between nullifying the pointer and freeing the memory, a reader can still access oplock_info structure after it has been freed. This can leads to a use-after-free especially in opinfo_get() where atomic_inc_not_zero() is called on already freed memory. Fix this by switching to deferred freeing using call_rcu().

CVSS Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH

Affected Products

VendorProductVersions
LinuxLinux Kernel>= 6.6.88, < 6.6.130

Related Weaknesses (CWE)

References

FAQ

What is CVE-2026-43376?

CVE-2026-43376 is a vulnerability with a CVSS score of 9.8 (CRITICAL). In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free by using call_rcu() for oplock_info ksmbd currently frees oplock_info immediately using kfree(), even th...

How severe is CVE-2026-43376?

CVE-2026-43376 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2026-43376?

Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.