Vulnerability in Linux

[ Description ]Official description

In the Linux kernel, the following vulnerability has been resolved: sctp: check RCV_SHUTDOWN after the sendmsg connect wait sctp_wait_for_connect() drops the socket lock while it sleeps. An out-of-the-blue ABORT can then be processed from the socket backlog and unlink the association. If a concurrent shutdown(fd, SHUT_RD) sets RCV_SHUTDOWN, the waiter breaks with err == 0 before checking asoc->base.dead. Its final sctp_association_put() can then free the association, leaving sctp_sendmsg_to_asoc() to continue with a dangling pointer. Check RCV_SHUTDOWN along with the wait error in sctp_sendmsg_to_asoc() before using the association again. The check only accesses the socket, so it needs no additional association reference. Return the existing -ESRCH so that sctp_sendmsg() skips freeing a new association that may already have been destroyed. Keep sctp_wait_for_connect() unchanged to preserve its behavior for the connect() caller.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund18 Oct 2026WID-SEC-2026-4019

  Linux Kernel: Multiple vulnerabilities Translated from German

  CVE-2026-98866CVE-2026-98624CVE-2026-98745+326 more CVEs

[ References ]References

• git.kernel.org/stable/c/1bef1944ef15a40797305bf916827b04df6307ca
• git.kernel.org/stable/c/222c41e0f50f1d5028be9baf0e1dcfc0bfa7f669
• git.kernel.org/stable/c/4f1da630d13de0370e2f6361f961f1c8b384af1c
• git.kernel.org/stable/c/e701345d886e831fb593a0870d69c8c5de6fc938
• git.kernel.org/stable/c/e8f972b1759d26bbefe4c524caae1ed7c8a593bd