ksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers
Summary
| CVE | CVE-2026-53271 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-25 09:16:45 UTC |
| Updated | 2026-06-25 09:16:45 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers smb2_oplock_break_noti() and smb2_lease_break_noti() read opinfo->conn into a local with neither READ_ONCE() nor a NULL check. Both run from oplock_break() after opinfo_get_list() has dropped ci->m_lock, so a concurrent SMB2 LOGOFF (session_fd_check()) can set op->conn = NULL under ci->m_lock within that window. ksmbd_conn_r_count_inc(conn) then writes through NULL at offset 0xc4 -- a remotely triggerable oops. Guard both reads the way compare_guid_key() already does: read opinfo->conn with READ_ONCE() and return early if it is NULL, before allocating the work struct so nothing leaks. A NULL conn means the client is gone and the break is moot, so return 0; oplock_break() treats that as success and runs the normal teardown. |
Risk And Classification
EPSS: 0.001640000 probability, percentile 0.058950000 (date 2026-06-25)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 8df4bcdb0a4232192b2445256c39b787d58ef14d 945a86b21b40fb17183f5b27461baa6f03e2467f git | Not specified |
| CNA | Linux | Linux | affected c8efcc786146a951091588e5fa7e3c754850cb3c 1ff58dcfcab434ebb51649da33774fbb8e1f7b67 git | Not specified |
| CNA | Linux | Linux | affected c8efcc786146a951091588e5fa7e3c754850cb3c e735dbd489e3ea02be78dba991056fe1138be51e git | Not specified |
| CNA | Linux | Linux | affected c8efcc786146a951091588e5fa7e3c754850cb3c 75e33deda658c1ab3a9336cbdb1436536f9b3660 git | Not specified |
| CNA | Linux | Linux | affected c8efcc786146a951091588e5fa7e3c754850cb3c b003086d76968298f22e7cf62239833b5a3a06b1 git | Not specified |
| CNA | Linux | Linux | affected 6.6.32 6.6.143 semver | Not specified |
| CNA | Linux | Linux | affected 6.9 | Not specified |
| CNA | Linux | Linux | unaffected 6.9 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.143 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.94 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.36 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0.13 7.0.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/1ff58dcfcab434ebb51649da33774fbb8e1f7b67 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/b003086d76968298f22e7cf62239833b5a3a06b1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/e735dbd489e3ea02be78dba991056fe1138be51e | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/75e33deda658c1ab3a9336cbdb1436536f9b3660 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/945a86b21b40fb17183f5b27461baa6f03e2467f | 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.