diff options
| author | Miklos Szeredi <mszeredi@redhat.com> | 2016-09-01 11:12:00 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-09-15 08:27:52 +0200 |
| commit | 708cb42fcaef0874a81100b461833096564db6cf (patch) | |
| tree | e0d57994e247a08747ee5d8c73854acbd5b76e5f /fs/overlayfs | |
| parent | d57a6c748059eb1f90cde4b40091f57617b72609 (diff) | |
ovl: listxattr: use strnlen()
commit 7cb35119d067191ce9ebc380a599db0b03cbd9d9 upstream.
Be defensive about what underlying fs provides us in the returned xattr
list buffer. If it's not properly null terminated, bail out with a warning
insead of BUG.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/overlayfs')
| -rw-r--r-- | fs/overlayfs/inode.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 8f8bce4d62e1..220b04f04523 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -277,7 +277,8 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size) struct path realpath; enum ovl_path_type type = ovl_path_real(dentry, &realpath); ssize_t res; - int off; + size_t len; + char *s; res = vfs_listxattr(realpath.dentry, list, size); if (res <= 0 || size == 0) @@ -287,17 +288,19 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size) return res; /* filter out private xattrs */ - for (off = 0; off < res;) { - char *s = list + off; - size_t slen = strlen(s) + 1; + for (s = list, len = res; len;) { + size_t slen = strnlen(s, len) + 1; - BUG_ON(off + slen > res); + /* underlying fs providing us with an broken xattr list? */ + if (WARN_ON(slen > len)) + return -EIO; + len -= slen; if (ovl_is_private_xattr(s)) { res -= slen; - memmove(s, s + slen, res - off); + memmove(s, s + slen, len); } else { - off += slen; + s += slen; } } |