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| author | Andy Whitcroft <apw@canonical.com> | 2011-11-02 09:44:39 +0100 |
|---|---|---|
| committer | Christoph Hellwig <hch@serles.lst.de> | 2011-11-02 12:53:42 +0100 |
| commit | 1fa1e7f615f4d3ae436fa319af6e4eebdd4026a8 (patch) | |
| tree | aa3521aaa762424cc7fb38dbf924a34dac1b03c2 /fs/stat.c | |
| parent | 32096ea1aac14e6f29d4744924092eca52b937b0 (diff) | |
| download | lwn-1fa1e7f615f4d3ae436fa319af6e4eebdd4026a8.tar.gz lwn-1fa1e7f615f4d3ae436fa319af6e4eebdd4026a8.zip | |
readlinkat: ensure we return ENOENT for the empty pathname for normal lookups
Since the commit below which added O_PATH support to the *at() calls, the
error return for readlink/readlinkat for the empty pathname has switched
from ENOENT to EINVAL:
commit 65cfc6722361570bfe255698d9cd4dccaf47570d
Author: Al Viro <viro@zeniv.linux.org.uk>
Date: Sun Mar 13 15:56:26 2011 -0400
readlinkat(), fchownat() and fstatat() with empty relative pathnames
This is both unexpected for userspace and makes readlink/readlinkat
inconsistant with all other interfaces; and inconsistant with our stated
return for these pathnames.
As the readlinkat call does not have a flags parameter we cannot use the
AT_EMPTY_PATH approach used in the other calls. Therefore expose whether
the original path is infact entry via a new user_path_at_empty() path
lookup function. Use this to determine whether to default to EINVAL or
ENOENT for failures.
Addresses http://bugs.launchpad.net/bugs/817187
[akpm@linux-foundation.org: remove unused getname_flags()]
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'fs/stat.c')
| -rw-r--r-- | fs/stat.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/stat.c b/fs/stat.c index 78a3aa83c7ea..8806b8997d2e 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -294,15 +294,16 @@ SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname, { struct path path; int error; + int empty = 0; if (bufsiz <= 0) return -EINVAL; - error = user_path_at(dfd, pathname, LOOKUP_EMPTY, &path); + error = user_path_at_empty(dfd, pathname, LOOKUP_EMPTY, &path, &empty); if (!error) { struct inode *inode = path.dentry->d_inode; - error = -EINVAL; + error = empty ? -ENOENT : -EINVAL; if (inode->i_op->readlink) { error = security_inode_readlink(path.dentry); if (!error) { |