net/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket
In the Linux kernel, the following vulnerability has been resolved: net/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket smc_cdc_rx_handler() looks up the connection by token under the link group's conns_lock, drops the lock, and then dereferences conn and the smc_sock derived from it, ending in sock_hold(&smc->sk) inside smc_cdc_msg_recv(). No reference is held across the lock release. The only reference pinning the socket while the connection is discoverable in the link group is taken in smc_lgr_register_conn() (sock_hold) and dropped in __smc_lgr_unregister_conn() (sock_put), both under conns_lock. Once the handler drops conns_lock, a concurrent close() -> smc_release() -> smc_conn_free() -> smc_lgr_unregister_conn() can drop that reference and free the smc_sock, so the handler's later sock_hold() runs on freed memory: WARNING: lib/refcount.c:25 at refcount_warn_saturate Workqueue: rxe_wq do_work refcount_warn_saturate (lib/refcount.c:25) smc_cdc_msg_recv (net/smc/smc_cdc.c:430) smc_cdc_rx_handler (net/smc/smc_cdc.c:502) smc_wr_rx_tasklet_fn (net/smc/smc_wr.c:445) tasklet_action_common (kernel/softirq.c:938) handle_softirqs (kernel/softirq.c:622) Kernel panic - not syncing: panic_on_warn set Only SMC-R is affected. The SMC-D receive tasklet is stopped by tasklet_kill(&conn->rx_tsklet) in smc_conn_free() before the connection is unregistered, so it cannot run concurrently with the free. Take the socket reference while still holding conns_lock, so the registration
CVE-2026-64541
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-64541
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "d7b0e37c1ac152905b18a5b9506179091a35b0b6",
"lessThan": "8de4f665d0febfb92803dece377791a563fc7041",
"versionType": "git"
},
{
"status": "affected",
"version": "d7b0e37c1ac152905b18a5b9506179091a35b0b6",
"lessThan": "8145b432136285e01091815b48ceb2dae261f262",
"versionType": "git"
},
{
"status": "affected",
"version": "d7b0e37c1ac152905b18a5b9506179091a35b0b6",
"lessThan": "1951bffbc6493ec34cff3956b29d4bc6606904a6",
"versionType": "git"
},
{
"status": "affected",
"version": "d7b0e37c1ac152905b18a5b9506179091a35b0b6",
"lessThan": "647b19e5cc145a2f1f685ae8ff3805a17356888c",
"versionType": "git"
},
{
"status": "affected",
"version": "d7b0e37c1ac152905b18a5b9506179091a35b0b6",
"lessThan": "472e9d7c0d5b03be3ff91ff941f57da822b031bc",
"versionType": "git"
},
{
"status": "affected",
"version": "d7b0e37c1ac152905b18a5b9506179091a35b0b6",
"lessThan": "3bfb96d9bc6a7ed0b99c7db329cc2e22a28d84bb",
"versionType": "git"
},
{
"status": "affected",
"version": "d7b0e37c1ac152905b18a5b9506179091a35b0b6",
"lessThan": "ce5aa8084329351086894aa34d77e40301d5bd3d",
"versionType": "git"
},
{
"status": "affected",
"version": "d7b0e37c1ac152905b18a5b9506179091a35b0b6",
"lessThan": "9d160b35cc34a2ba8229d07651468a7848325135",
"versionType": "git"
}
],
"programFiles": [
"net/smc/smc_cdc.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.18"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.18",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/smc/smc_cdc.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-64541
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #41073 · Revision 1
- Added to Heist Feed
- Publisher date