[PATCH] honour MNT_NOEXEC for access()

Make access(X_OK) take the "noexec" mount option into account.

Signed-off-by: Stas Sergeev <stsp@aknet.ru>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/namei.c

@@ -249,9 +249,11 @@ int permission(struct inode *inode, int mask, struct nameidata *nd)
 
 	/*
 	 * MAY_EXEC on regular files requires special handling: We override
-	 * filesystem execute permissions if the mode bits aren't set.
+	 * filesystem execute permissions if the mode bits aren't set or
+	 * the fs is mounted with the "noexec" flag.
 	 */
-	if ((mask & MAY_EXEC) && S_ISREG(mode) && !(mode & S_IXUGO))
+	if ((mask & MAY_EXEC) && S_ISREG(mode) && (!(mode & S_IXUGO) ||
+			(nd && nd->mnt && (nd->mnt->mnt_flags & MNT_NOEXEC))))
 		return -EACCES;
 
 	/* Ordinary permission routines do not understand MAY_APPEND. */