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.
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.
Published:
2026-10-06
Score:
n/a
EPSS:
n/a
KEV:
No
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
Remediation
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
Sign in to view the affected projects.
Advisories
No advisories yet.
References
History
Tue, 06 Oct 2026 09:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | smb: client: fix use-after-free of iface in cifs_try_adding_channels() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-06T08:44:17.567Z
Reserved: 2026-09-25T10:25:14.322Z
Link: CVE-2026-98173
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-06T09:17:59.060
Modified: 2026-10-06T09:17:59.060
Link: CVE-2026-98173
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.