{"id":"CVE-2026-80984","title":"net/smc: do not dereference an unset send buffer on the SMC-D teardown path","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: do not dereference an unset send buffer on the SMC-D teardown path\n\nsmc_close_stream_wait() calls smc_tx_prepared_sends() from inside its\nsk_wait_event() condi…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":["CWE-476"],"vendor":"Linux","product":"Linux","affected":["Linux >= 21f6f41e82e59740e26e06e77bdf58dc7f6f08dd < ab26e12dd5d2f43d939fcf456933a816e81d2e51","Linux >= ae2be35cbed2c8385e890147ea321a3fcc3ca5fa < e3fcff8d22a6c9540748846cd800443a643553a6","Linux >= ae2be35cbed2c8385e890147ea321a3fcc3ca5fa < f950e1b1f0aad334f9a9ee552c4dd5b794ebdd45","Linux >= ae2be35cbed2c8385e890147ea321a3fcc3ca5fa < f517cf02033801a28f98d86ca613a3533cf066b3","Linux >= ae2be35cbed2c8385e890147ea321a3fcc3ca5fa < b395dd319cea422239cb45b998fb38d7e373af87","Linux >= 6.6.66 < 6.6.157","Linux 6.10"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:46:08.671Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80984","references":[{"url":"https://git.kernel.org/stable/c/ab26e12dd5d2f43d939fcf456933a816e81d2e51"},{"url":"https://git.kernel.org/stable/c/e3fcff8d22a6c9540748846cd800443a643553a6"},{"url":"https://git.kernel.org/stable/c/f950e1b1f0aad334f9a9ee552c4dd5b794ebdd45"},{"url":"https://git.kernel.org/stable/c/f517cf02033801a28f98d86ca613a3533cf066b3"},{"url":"https://git.kernel.org/stable/c/b395dd319cea422239cb45b998fb38d7e373af87"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80984.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-80984"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532437"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80984"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80984"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80984.mbox"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.00206,"epssPercentile":0.10486,"ingestedAt":"2026-09-14T15:23:07.454Z","slug":"CVE-2026-80984","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: do not dereference an unset send buffer on the SMC-D teardown path\n\nsmc_close_stream_wait() calls smc_tx_prepared_sends() from inside its\nsk_wait_event() condition, and sk_wait_event() evaluates that condition\nonce with the socket lock released. smcd_buf_detach() clears\nconn->sndbuf_desc from smc_conn_kill() under lock_sock(), so a link group\nterminating while a socket waits there leaves the helper dereferencing\nNULL, faulting out of close(). SIOCOUTQ reads the field by hand, and\nsmc_close_cancel_work() drops the lock across two cancel_*_sync() calls.\n\nSample the pointer once in the helper, report nothing prepared while it is\nunset, and bound the ioctl the same way. The receive tasklet dereferences\nthe field directly in smc_cdc_msg_recv_action(), not through this helper;\n1/2 is what keeps it from running that late.\n\n## Affected\n\n- `Linux >= 21f6f41e82e59740e26e06e77bdf58dc7f6f08dd < ab26e12dd5d2f43d939fcf456933a816e81d2e51`\n- `Linux >= ae2be35cbed2c8385e890147ea321a3fcc3ca5fa < e3fcff8d22a6c9540748846cd800443a643553a6`\n- `Linux >= ae2be35cbed2c8385e890147ea321a3fcc3ca5fa < f950e1b1f0aad334f9a9ee552c4dd5b794ebdd45`\n- `Linux >= ae2be35cbed2c8385e890147ea321a3fcc3ca5fa < f517cf02033801a28f98d86ca613a3533cf066b3`\n- `Linux >= ae2be35cbed2c8385e890147ea321a3fcc3ca5fa < b395dd319cea422239cb45b998fb38d7e373af87`\n- `Linux >= 6.6.66 < 6.6.157`\n- `Linux 6.10`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80984.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":204165,"id":"CVE-2026-80984","ts":1789490235225,"field":"cvss","old":null,"new":"5.5"},{"seq":204164,"id":"CVE-2026-80984","ts":1789490235225,"field":"severity","old":"none","new":"medium"},{"seq":147243,"id":"CVE-2026-80984","ts":1789270203890,"field":"cvss","old":null,"new":"4.7"},{"seq":147242,"id":"CVE-2026-80984","ts":1789270203890,"field":"severity","old":"none","new":"medium"},{"seq":108994,"id":"CVE-2026-80984","ts":1789183729878,"field":"cvss","old":null,"new":"4.7"},{"seq":108993,"id":"CVE-2026-80984","ts":1789183729878,"field":"severity","old":"none","new":"medium"}]}