Description
In the Linux kernel, the following vulnerability has been resolved:
net/smc: free stashed qentry before overwrite in REQ_ADD_LINK to ADD_LINK transition
When smc_llc_event_handler() transitions the local LLC flow from
SMC_LLC_FLOW_REQ_ADD_LINK to SMC_LLC_FLOW_ADD_LINK on arrival of an ADD_LINK
request, it calls smc_llc_flow_qentry_set() unconditionally:
if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_REQ_ADD_LINK) {
lgr->llc_flow_lcl.type = SMC_LLC_FLOW_ADD_LINK;
smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
...
}
A CONFIRM_LINK or ADD_LINK_CONT arriving while flow->type is
SMC_LLC_FLOW_REQ_ADD_LINK is stashed into flow->qentry via the
SMC_LLC_CONFIRM_LINK / SMC_LLC_ADD_LINK_CONT handler (which stores into
flow->qentry for any non-NONE flow type). When the subsequent ADD_LINK
arrives, the REQ_ADD_LINK branch overwrites flow->qentry with the new pointer
without first freeing the stashed allocation, leaking one kmalloc object.
The stashed entry has no consumer: smc_llc_wait() is only called from
llc_add_link_work, which is not yet scheduled while the flow type remains
REQ_ADD_LINK. No waiter is sleeping on llc_msg_waiter at this point.
It is safe to unconditionally free any stashed qentry before
the overwrite.
Call smc_llc_flow_qentry_del() before smc_llc_flow_qentry_set() in the
REQ_ADD_LINK branch. smc_llc_flow_qentry_del() already checks flow->qentry
before freeing, so the normal path where no entry is stashed is a no-op.
net/smc: free stashed qentry before overwrite in REQ_ADD_LINK to ADD_LINK transition
When smc_llc_event_handler() transitions the local LLC flow from
SMC_LLC_FLOW_REQ_ADD_LINK to SMC_LLC_FLOW_ADD_LINK on arrival of an ADD_LINK
request, it calls smc_llc_flow_qentry_set() unconditionally:
if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_REQ_ADD_LINK) {
lgr->llc_flow_lcl.type = SMC_LLC_FLOW_ADD_LINK;
smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
...
}
A CONFIRM_LINK or ADD_LINK_CONT arriving while flow->type is
SMC_LLC_FLOW_REQ_ADD_LINK is stashed into flow->qentry via the
SMC_LLC_CONFIRM_LINK / SMC_LLC_ADD_LINK_CONT handler (which stores into
flow->qentry for any non-NONE flow type). When the subsequent ADD_LINK
arrives, the REQ_ADD_LINK branch overwrites flow->qentry with the new pointer
without first freeing the stashed allocation, leaking one kmalloc object.
The stashed entry has no consumer: smc_llc_wait() is only called from
llc_add_link_work, which is not yet scheduled while the flow type remains
REQ_ADD_LINK. No waiter is sleeping on llc_msg_waiter at this point.
It is safe to unconditionally free any stashed qentry before
the overwrite.
Call smc_llc_flow_qentry_del() before smc_llc_flow_qentry_set() in the
REQ_ADD_LINK branch. smc_llc_flow_qentry_del() already checks flow->qentry
before freeing, so the normal path where no entry is stashed is a no-op.
Published:
2026-09-17
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis and contextual insights are available on OpenCVE Cloud.
Remediation
No vendor fix or workaround currently provided.
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Tracking
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Advisories
No advisories yet.
References
History
Thu, 17 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: net/smc: free stashed qentry before overwrite in REQ_ADD_LINK to ADD_LINK transition When smc_llc_event_handler() transitions the local LLC flow from SMC_LLC_FLOW_REQ_ADD_LINK to SMC_LLC_FLOW_ADD_LINK on arrival of an ADD_LINK request, it calls smc_llc_flow_qentry_set() unconditionally: if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_REQ_ADD_LINK) { lgr->llc_flow_lcl.type = SMC_LLC_FLOW_ADD_LINK; smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry); ... } A CONFIRM_LINK or ADD_LINK_CONT arriving while flow->type is SMC_LLC_FLOW_REQ_ADD_LINK is stashed into flow->qentry via the SMC_LLC_CONFIRM_LINK / SMC_LLC_ADD_LINK_CONT handler (which stores into flow->qentry for any non-NONE flow type). When the subsequent ADD_LINK arrives, the REQ_ADD_LINK branch overwrites flow->qentry with the new pointer without first freeing the stashed allocation, leaking one kmalloc object. The stashed entry has no consumer: smc_llc_wait() is only called from llc_add_link_work, which is not yet scheduled while the flow type remains REQ_ADD_LINK. No waiter is sleeping on llc_msg_waiter at this point. It is safe to unconditionally free any stashed qentry before the overwrite. Call smc_llc_flow_qentry_del() before smc_llc_flow_qentry_set() in the REQ_ADD_LINK branch. smc_llc_flow_qentry_del() already checks flow->qentry before freeing, so the normal path where no entry is stashed is a no-op. | |
| Title | net/smc: free stashed qentry before overwrite in REQ_ADD_LINK to ADD_LINK transition | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-17T16:06:16.813Z
Reserved: 2026-09-11T19:38:34.787Z
Link: CVE-2026-90108
No data.
Status : Received
Published: 2026-09-17T17:17:02.730
Modified: 2026-09-17T17:17:02.730
Link: CVE-2026-90108
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.