CVE-2026-80984: Linux kernel · net/smc: do not dereference an unset send buffer on the SMC-D teardown path
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 14:05 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
The description indicates the vulnerability has been resolved, implying a fix is available. Users should apply the official Linux kernel updates that address this issue once released.
Description
In the Linux kernel, the following vulnerability has been resolved: net/smc: do not dereference an unset send buffer on the SMC-D teardown path smc_close_stream_wait() calls smc_tx_prepared_sends() from inside its sk_wait_event() condition, and sk_wait_event() evaluates that condition once with the socket lock released. smcd_buf_detach() clears conn->sndbuf_desc from smc_conn_kill() under lock_sock(), so a link group terminating while a socket waits there leaves the helper dereferencing NULL, faulting out of close(). SIOCOUTQ reads the field by hand, and smc_close_cancel_work() drops the lock across two cancel_*_sync() calls. Sample the pointer once in the helper, report nothing prepared while it is unset, and bound the ioctl the same way. The receive tasklet dereferences the field directly in smc_cdc_msg_recv_action(), not through this helper; 1/2 is what keeps it from running that late.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80984 (opens in a new tab)
- git.kernel.org/stable/c/b395dd319cea422239cb45b998fb38d7e373af87 (opens in a new tab)
- git.kernel.org/stable/c/e3fcff8d22a6c9540748846cd800443a643553a6 (opens in a new tab)
- git.kernel.org/stable/c/f517cf02033801a28f98d86ca613a3533cf066b3 (opens in a new tab)
- git.kernel.org/stable/c/f950e1b1f0aad334f9a9ee552c4dd5b794ebdd45 (opens in a new tab)
- ubuntu.com/security/CVE-2026-80984 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80984 (opens in a new tab)
- git.kernel.org/linus/b395dd319cea422239cb45b998fb38d7e373af87 (opens in a new tab)