diff options
| author | Miklos Szeredi <mszeredi@redhat.com> | 2016-10-01 07:32:32 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-10-22 12:26:55 +0200 |
| commit | 80b742b84f85e3688e02eefd8b820642c4635329 (patch) | |
| tree | ee694fadb4c68fec160cbf59e071afa22b132301 /fs | |
| parent | 1ccdc775631e5d636d796cc92b07852d319e9a09 (diff) | |
fuse: listxattr: verify xattr list
commit cb3ae6d25a5471be62bfe6ac1fccc0e91edeaba0 upstream.
Make sure userspace filesystem is returning a well formed list of xattr
names (zero or more nonzero length, null terminated strings).
[Michael Theall: only verify in the nonzero size case]
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/fuse/dir.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 5e2e08712d3b..67c0d1046c61 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -1797,6 +1797,23 @@ static ssize_t fuse_getxattr(struct dentry *entry, const char *name, return ret; } +static int fuse_verify_xattr_list(char *list, size_t size) +{ + size_t origsize = size; + + while (size) { + size_t thislen = strnlen(list, size); + + if (!thislen || thislen == size) + return -EIO; + + size -= thislen + 1; + list += thislen + 1; + } + + return origsize; +} + static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size) { struct inode *inode = d_inode(entry); @@ -1832,6 +1849,8 @@ static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size) ret = fuse_simple_request(fc, &args); if (!ret && !size) ret = outarg.size; + if (ret > 0 && size) + ret = fuse_verify_xattr_list(list, ret); if (ret == -ENOSYS) { fc->no_listxattr = 1; ret = -EOPNOTSUPP; |