untrusted comment: verify with openbsd-70-base.pub RWR3KL+gSr4QZ69kIA/hbF1Wt7RWm5lEPC7L2kpcxqZ7lZYBfJm+LS5/6iluFgMecOXBFnTmQ8FGs3je1OItpFJLEfMtuupyDws= OpenBSD 7.0 errata 005, November 26, 2021: An unprivileged user could crash the kernel by using UNIX-domain sockets in multiple threads. Apply by doing: signify -Vep /etc/signify/openbsd-70-base.pub -x 005_unpcon.patch.sig \ -m - | (cd /usr/src && patch -p0) And then rebuild and install a new kernel: KK=`sysctl -n kern.osversion | cut -d# -f1` cd /usr/src/sys/arch/`machine`/compile/$KK make obj make config make make install Index: sys/kern/uipc_usrreq.c =================================================================== RCS file: /cvs/src/sys/kern/uipc_usrreq.c,v diff -u -p -r1.148.2.1 uipc_usrreq.c --- sys/kern/uipc_usrreq.c 30 Oct 2021 18:11:56 -0000 1.148.2.1 +++ sys/kern/uipc_usrreq.c 17 Nov 2021 21:34:28 -0000 @@ -690,6 +690,13 @@ unlock: solock(so); unp->unp_flags &= ~UNP_CONNECTING; + /* + * The peer socket could be closed by concurrent thread + * when `so' and `vp' are unlocked. + */ + if (error == 0 && unp->unp_conn == NULL) + error = ECONNREFUSED; + return (error); }