From 65cfc6722361570bfe255698d9cd4dccaf47570d Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 13 Mar 2011 15:56:26 -0400 Subject: readlinkat(), fchownat() and fstatat() with empty relative pathnames For readlinkat() we simply allow empty pathname; it will fail unless we have dfd equal to O_PATH-opened symlink, so we are outside of POSIX scope here. For fchownat() and fstatat() we allow AT_EMPTY_PATH; let the caller explicitly ask for such behaviour. Signed-off-by: Al Viro --- fs/stat.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'fs/stat.c') diff --git a/fs/stat.c b/fs/stat.c index d5c61cf2b703..961039121cb8 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -75,13 +75,16 @@ int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat, int error = -EINVAL; int lookup_flags = 0; - if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT)) != 0) + if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | + AT_EMPTY_PATH)) != 0) goto out; if (!(flag & AT_SYMLINK_NOFOLLOW)) lookup_flags |= LOOKUP_FOLLOW; if (flag & AT_NO_AUTOMOUNT) lookup_flags |= LOOKUP_NO_AUTOMOUNT; + if (flag & AT_EMPTY_PATH) + lookup_flags |= LOOKUP_EMPTY; error = user_path_at(dfd, filename, lookup_flags, &path); if (error) @@ -297,7 +300,7 @@ SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname, if (bufsiz <= 0) return -EINVAL; - error = user_path_at(dfd, pathname, 0, &path); + error = user_path_at(dfd, pathname, LOOKUP_EMPTY, &path); if (!error) { struct inode *inode = path.dentry->d_inode; -- cgit v1.2.3-59-g8ed1b