CVE-2026-98173smb: client: fix use-after-free of iface in cifs_try_adding_channels()
- 7.5HighCVSS base score
- 0.34%Exploitation in 30 daysEPSS · top 72% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix use-after-free of iface in cifs_try_adding_channels() cifs_try_adding_channels() iterates ses->iface_list with list_for_each_entry_safe_from(), which captures the next entry (niface) under iface_lock. The loop body then drops iface_lock for the whole duration of cifs_ses_add_channel(). A concurrent interface refresh (SMB3_request_interfaces() -> parse_server_interfaces()) marks all ifaces inactive and removes and frees any that are not re-advertised via list_del() + kref_put(), where release_iface() is a bare kfree(). Since niface typically has no channel holding a reference, the list reference is its last and it can be freed inside the unlocked window. On continue, the iterator advance step then dereferences niface->iface_head.next, and the loop body reads iface->rdma_capable/is_active, both on freed memory. Fix this by never keeping an unreferenced list pointer across the unlocked window. Each channel attempt now re-scans the list from the head under iface_lock, takes a kref on the selected candidate, and passes only that referenced candidate to cifs_ses_add_channel(). weight_fulfilled still tracks selection progress, so restarting the scan preserves the original weighted distribution and the weight_fulfilled-before-kref_put ordering on the failure path. Add a per-pass attempts cap so a flapping interface refresh cannot keep the inner loop spinning within a single tries increment.
Timeline
ID reserved
By Linux
- 11 days later
· 11 days later
Published
- 24 days later
· 24 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H |
| NVDNVD · Received | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.34% · top 72% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
- affected aa45dadd34e44fcd6a9df4b395bee5b5633b4cec – < 93e8a49adb2a575202c5ee766435eff2f9f95f5b
- affected aa45dadd34e44fcd6a9df4b395bee5b5633b4cec – < ee0d8f83d68f6e6509f092c997ccab3c8c801538
- affected aa45dadd34e44fcd6a9df4b395bee5b5633b4cec – < c941f1ebfd26f683de81091473f3596a218abff0
- affected aa45dadd34e44fcd6a9df4b395bee5b5633b4cec – < e99040e5e9c60441e6b4725e1a7b88c3106ae903
- affected aa45dadd34e44fcd6a9df4b395bee5b5633b4cec – < ec36b38e65596950e6c29bed7dfc90b98707c19c
- affected aa45dadd34e44fcd6a9df4b395bee5b5633b4cec – < d034e836eefd7ce75e588f7031cffbeec594f5ac
- affected 5.19
- unaffected < 5.19
- unaffected 6.1.191 – ≤ 6.1.*
- unaffected 6.6.160 – ≤ 6.6.*
- unaffected 6.12.112 – ≤ 6.12.*
- unaffected 6.18.54 – ≤ 6.18.*
- unaffected 7.2.8 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References6
- https://git.kernel.org/stable/c/93e8a49adb2a575202c5ee766435eff2f9f95f5b (opens in a new tab)
- https://git.kernel.org/stable/c/ee0d8f83d68f6e6509f092c997ccab3c8c801538 (opens in a new tab)
- https://git.kernel.org/stable/c/c941f1ebfd26f683de81091473f3596a218abff0 (opens in a new tab)
- https://git.kernel.org/stable/c/e99040e5e9c60441e6b4725e1a7b88c3106ae903 (opens in a new tab)
- https://git.kernel.org/stable/c/ec36b38e65596950e6c29bed7dfc90b98707c19c (opens in a new tab)
- https://git.kernel.org/stable/c/d034e836eefd7ce75e588f7031cffbeec594f5ac (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-93101 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-98173)Record last updated .