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 though it is accessed under RCU read-side critical…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.44%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.44% probability · 38th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/08aa9f3c8cf4d0bee44df540dfe34e8d64069f2cPatch
- https://git.kernel.org/stable/c/1d6abf145615dbfe267ce3b0a271f95e3780e18ePatch
- https://git.kernel.org/stable/c/1dfd062caa165ec9d7ee0823087930f3ab8a6294Patch
- https://git.kernel.org/stable/c/302fef75512b2c8329a3f5efab1ae7ba2562387aPatch
- https://git.kernel.org/stable/c/ce8507ee82c888126d8e7565e27c016308d24cdePatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.