From 0f600883990ea96d2026389cfe84ca6130f6d3aa Mon Sep 17 00:00:00 2001 From: Mateusz Guzik Date: Fri, 25 Mar 2022 18:19:36 +0000 Subject: [PATCH] vfs: set cn_namelen when handling degenerate lookups Turns out execve looks at it to store binary name, but in order to trigger the problem one has to be trying to exec '/'. As is the value would be left uninitialized (or rather set to -1 on debug kernels). Fixes: 56244d35741a62e7 ("vfs: hoist degenerate path lookups out of the loop") --- sys/kern/vfs_lookup.c | 1 + 1 file changed, 1 insertion(+) diff --git a/sys/kern/vfs_lookup.c b/sys/kern/vfs_lookup.c index 71173d189ef2..faef7b6cb254 100644 --- a/sys/kern/vfs_lookup.c +++ b/sys/kern/vfs_lookup.c @@ -853,6 +853,7 @@ vfs_lookup_degenerate(struct nameidata *ndp, struct vnode *dp, int wantparent) VREF(dp); } ndp->ni_vp = dp; + cnp->cn_namelen = 0; if (cnp->cn_flags & AUDITVNODE1) AUDIT_ARG_VNODE1(dp);