CVE-2026-43376
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().
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-43376
Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2026-43376.html
Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/ce8507ee82c888126d8e7565e27c016308d24cde
Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/302fef75512b2c8329a3f5efab1ae7ba2562387a
Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/1dfd062caa165ec9d7ee0823087930f3ab8a6294
Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/1d6abf145615dbfe267ce3b0a271f95e3780e18e
Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 0 |
| debian | bullseye | fixed | 0 |
| debian | forky | fixed | 6.19.10-1 |
| debian | sid | fixed | 6.19.10-1 |
| debian | trixie | fixed | 6.12.85-1 |
| linux-kernel | affected | 6.6.130 | |
| linux-kernel | 6.15 | affected | |
| linux-kernel | 7.0 | affected | |
References
- https://git.kernel.org/stable/c/08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c
- https://git.kernel.org/stable/c/1d6abf145615dbfe267ce3b0a271f95e3780e18e
- https://git.kernel.org/stable/c/1dfd062caa165ec9d7ee0823087930f3ab8a6294
- https://git.kernel.org/stable/c/302fef75512b2c8329a3f5efab1ae7ba2562387a
- https://git.kernel.org/stable/c/ce8507ee82c888126d8e7565e27c016308d24cde
- https://www.suse.com/security/cve/CVE-2026-43376.html
- https://security-tracker.debian.org/tracker/CVE-2026-43376
CWEs
CWE-416
Verify integrity in audit chain (admin only). AS-IS.