ksmbd: fix use-after-free by using call_rcu() for oplock_info
Priority MEDIUM 42CWE-416Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-416 and the CVSS impact.
Summary
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().
Why it matters now
EPSS 0.00444 38th percentileScored 2026-11-07
Fix Fixed Linux (Linux): 6.6.130, 6.12.78, 6.15 +3
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 6.6.88 to before 6.6.130; 6.12.25 to before 6.12.78; 6.14.4 to before 6.15 | 6.6.130, 6.12.78, 6.15 | Patch available | CNA |
| Linux | Linux | 6.15 and later | 6.6.130, 6.12.78, 6.18.19, 6.19.9, 7.0 | Patch available | CNA |
- Linux VendorLinux Affected 6.6.88 to before 6.6.130; 6.12.25 to before 6.12.78; 6.14.4 to before 6.15 Fixed in 6.6.130, 6.12.78, 6.15 Patch available CNA
- Linux VendorLinux Affected 6.15 and later Fixed in 6.6.130, 6.12.78, 6.18.19, 6.19.9, 7.0 Patch available CNA
CPE configurations NVD · 10
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 6.6.88 to before 6.6.130; 6.12.25 to before 6.12.78; 6.14.4 to before 6.15; 6.15.1 to before 6.18.19; 6.19 to before 6.19.9 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:-:*:*:*:*:*:* | 6.15 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:* | 6.15 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:* | 6.15 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc5:*:*:*:*:*:* | 6.15 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc6:*:*:*:*:*:* | 6.15 rc6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc7:*:*:*:*:*:* | 6.15 rc7 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* | 7.0 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* | 7.0 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* | 7.0 rc3 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.6.88 to before 6.6.130; 6.12.25 to before 6.12.78; 6.14.4 to before 6.15; 6.15.1 to before 6.18.19; 6.19 to before 6.19.9 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:-:*:*:*:*:*:* Versions 6.15 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:* Versions 6.15 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:* Versions 6.15 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc5:*:*:*:*:*:* Versions 6.15 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc6:*:*:*:*:*:* Versions 6.15 rc6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc7:*:*:*:*:*:* Versions 6.15 rc7 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* Versions 7.0 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* Versions 7.0 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* Versions 7.0 rc3 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.6.130, 6.12.78, 6.15
- Fix · CNA Linux (Linux) Fixed in 6.6.130, 6.12.78, 6.18.19, 6.19.9, 7.0
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 5 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-43376
- 2026-10-03 Alias added: GHSA-3v8x-c22j-hv4q
- 2026-10-14 EPSS moved to the 50th–90th percentile
- 2026-10-20 Affected versions changed · Red Hat
- 2026-10-25 EPSS moved to the below the 50th percentile
References
Patch 5
- https://git.kernel.org/stable/c/302fef75512b2c8329a3f5efab1ae7ba2562387a
- https://git.kernel.org/stable/c/08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c
- https://git.kernel.org/stable/c/1d6abf145615dbfe267ce3b0a271f95e3780e18e
- https://git.kernel.org/stable/c/ce8507ee82c888126d8e7565e27c016308d24cde
- https://git.kernel.org/stable/c/1dfd062caa165ec9d7ee0823087930f3ab8a6294
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-43376 · CVE Program
- CVE-2026-43376 · NVD
- FIRST EPSS
- GHSA-3v8x-c22j-hv4q · GitHub Advisory Database · CC BY 4.0
- CVE-2026-43376 · Red Hat security data · CC BY 4.0
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