git: 6de3cf14c47d - main - vn_open_cred(): disallow O_CREAT | O_EMPTY_PATH

[Konstantin Belousov]

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=6de3cf14c47d97b423ae25d5bd1d80b896ecd9e6

commit 6de3cf14c47d97b423ae25d5bd1d80b896ecd9e6
Author:     Konstantin Belousov <kib at FreeBSD.org>
AuthorDate: 2021-05-12 19:04:44 +0000
Commit:     Konstantin Belousov <kib at FreeBSD.org>
CommitDate: 2021-05-12 23:32:04 +0000

    vn_open_cred(): disallow O_CREAT | O_EMPTY_PATH
    
    This combination does not make sense, and cannot be satisfied by lookup.
    In particular, lookup cannot supply dvp, it only can directly return vp.
    
    Reported and reviewed by:       markj using syzkaller
    Sponsored by:   The FreeBSD Foundation
    MFC after:      3 days
---
 sys/kern/vfs_vnops.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index 670bc4bf8fcc..8f583329f067 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -233,7 +233,8 @@ restart:
 	first_open = false;
 	fmode = *flagp;
 	if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT |
-	    O_EXCL | O_DIRECTORY))
+	    O_EXCL | O_DIRECTORY) ||
+	    (fmode & (O_CREAT | O_EMPTY_PATH)) == (O_CREAT | O_EMPTY_PATH))
 		return (EINVAL);
 	else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) {
 		ndp->ni_cnd.cn_nameiop = CREATE;