ksmbd: fix use-after-free by using call_rcu() for oplock_info
Summary
| CVE | CVE-2026-43376 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-08 15:16:48 UTC |
| Updated | 2026-05-11 08:16:12 UTC |
| 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(). |
Risk And Classification
Primary CVSS: v3.1 9.8 CRITICAL from 416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.000180000 probability, percentile 0.049330000 (date 2026-05-10)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Secondary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 296cb5457cc6f4a754c4ae29855f8a253d52bcc6 302fef75512b2c8329a3f5efab1ae7ba2562387a git | Not specified |
| CNA | Linux | Linux | affected d54ab1520d43e95f9b2e22d7a05fc9614192e5a5 08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c git | Not specified |
| CNA | Linux | Linux | affected 18b4fac5ef17f77fed9417d22210ceafd6525fc7 1d6abf145615dbfe267ce3b0a271f95e3780e18e git | Not specified |
| CNA | Linux | Linux | affected 18b4fac5ef17f77fed9417d22210ceafd6525fc7 ce8507ee82c888126d8e7565e27c016308d24cde git | Not specified |
| CNA | Linux | Linux | affected 18b4fac5ef17f77fed9417d22210ceafd6525fc7 1dfd062caa165ec9d7ee0823087930f3ab8a6294 git | Not specified |
| CNA | Linux | Linux | affected d73686367ad68534257cd88a36ca3c52cb8b81d8 git | Not specified |
| CNA | Linux | Linux | affected 6.15 | Not specified |
| CNA | Linux | Linux | unaffected 6.15 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.130 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.78 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.19 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.19.9 6.19.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/302fef75512b2c8329a3f5efab1ae7ba2562387a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/1dfd062caa165ec9d7ee0823087930f3ab8a6294 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/1d6abf145615dbfe267ce3b0a271f95e3780e18e | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/ce8507ee82c888126d8e7565e27c016308d24cde | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.