From 20afcc23b3212784c84fb06062f66d9d2ce6865d Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Fri, 12 Mar 2021 15:10:01 +0100 Subject: [PATCH] virtiofsd: Don't allow empty paths in lookup_name() When passed an empty filename, lookup_name() returns the inode of the parent directory, unless the parent is the root in which case the st_dev doesn't match and lo_find() returns NULL. This is because lookup_name() passes AT_EMPTY_PATH down to fstatat() or statx(). This behavior doesn't quite make sense because users of lookup_name() then pass the name to unlinkat(), renameat() or renameat2(), all of which will always fail on empty names. Drop AT_EMPTY_PATH from the flags in lookup_name() so that it has the consistent behavior of "returning an existing child inode or NULL" for all directories. Signed-off-by: Greg Kurz Message-Id: <20210312141003.819108-2-groug@kaod.org> Reviewed-by: Connor Kuehl Reviewed-by: Vivek Goyal Signed-off-by: Dr. David Alan Gilbert --- tools/virtiofsd/passthrough_ll.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index b07101d8eb..cf453eea9b 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -1330,8 +1330,7 @@ static struct lo_inode *lookup_name(fuse_req_t req, fuse_ino_t parent, return NULL; } - res = do_statx(lo, dir->fd, name, &attr, - AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW, &mnt_id); + res = do_statx(lo, dir->fd, name, &attr, AT_SYMLINK_NOFOLLOW, &mnt_id); lo_inode_put(lo, &dir); if (res == -1) { return NULL;