cache: only assert on flags when dealing with EMPTYPATH

Reported by:	syzbot+bd48ee0843206a09e6b8@syzkaller.appspotmail.com
Fixes:		7dd419cabc6bb9e0 ("cache: add empty path support")

(cherry picked from commit 1045352f150346ba422b3a3ce6344fc694bc3aa4)

diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c
index 313879cf6d1f21edecab29125f29cd1402e1465c..14e148b2f839b29288fbde7a7ac94e97306534bd 100644 (file)
--- a/sys/kern/vfs_cache.c
+++ b/sys/kern/vfs_cache.c
@@ -4784,13 +4784,14 @@ cache_fplookup_emptypath(struct cache_fpl *fpl)
        tvp_seqc = fpl->tvp_seqc;
 
        MPASS(*cnp->cn_pnbuf == '\0');
-       MPASS((cnp->cn_flags & (LOCKPARENT | WANTPARENT)) == 0);
 
        if (__predict_false((cnp->cn_flags & EMPTYPATH) == 0)) {
                cache_fpl_smr_exit(fpl);
                return (cache_fpl_handled_error(fpl, ENOENT));
        }
 
+       MPASS((cnp->cn_flags & (LOCKPARENT | WANTPARENT)) == 0);
+
        tvs = vget_prep_smr(tvp);
        cache_fpl_smr_exit(fpl);
        if (__predict_false(tvs == VGET_NONE)) {