CVE-2026-43376 Details
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().
A use-after-free vulnerability has been identified in the Linux kernel's ksmbd component, specifically in the handling of oplock_info structures. This issue arises because ksmbd frees oplock_info immediately using kfree(), without allowing for a proper RCU grace period. As a result, the oplock_info can be accessed after it has been freed, leading to a use-after-free condition. This is particularly problematic in the opinfo_get() function, where atomic_inc_not_zero() is called on already freed memory.
The vulnerability has been fixed by changing the memory management of the oplock_info structure to use deferred freeing with call_rcu(), which properly handles the RCU grace period.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c | kernel.org | Patch |
| https://git.kernel.org/stable/c/1d6abf145615dbfe267ce3b0a271f95e3780e18e | kernel.org | Patch |
| https://git.kernel.org/stable/c/1dfd062caa165ec9d7ee0823087930f3ab8a6294 | kernel.org | Patch |
| https://git.kernel.org/stable/c/302fef75512b2c8329a3f5efab1ae7ba2562387a | kernel.org | Patch |
| https://git.kernel.org/stable/c/ce8507ee82c888126d8e7565e27c016308d24cde | kernel.org | Patch |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-416 | Use After Free | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 6.6.88, < 6.6.130 >= 6.12.25, < 6.12.78 >= 6.14.4, < 6.15 >= 6.15.1, < 6.18.19 >= 6.19, < 6.19.9 6.15 - 6.15 rc3 6.15 rc4 6.15 rc5 6.15 rc6 6.15 rc7 7.0 rc1 7.0 rc2 7.0 rc3 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | kernel.org |
| May 15, 2026 | Initial Analysis | [email protected] |
| May 11, 2026 | CVE Modified | kernel.org |
| May 8, 2026 | New CVE Received | kernel.org |