On Tue, Jan 08, 2019 at 12:36:29PM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> Check directory entry names for invalid characters.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
> fs/xfs/libxfs/xfs_dir2.c | 17 +++++++++++++++++
> fs/xfs/libxfs/xfs_dir2.h | 1 +
> fs/xfs/scrub/dir.c | 6 ++++++
> 3 files changed, 24 insertions(+)
>
>
> diff --git a/fs/xfs/libxfs/xfs_dir2.c b/fs/xfs/libxfs/xfs_dir2.c
> index 229152cd1a24..156ce95c9c45 100644
> --- a/fs/xfs/libxfs/xfs_dir2.c
> +++ b/fs/xfs/libxfs/xfs_dir2.c
> @@ -703,3 +703,20 @@ xfs_dir2_shrink_inode(
> xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
> return 0;
> }
> +
> +/* Returns true if the directory entry name is valid. */
> +bool
> +xfs_dir2_namecheck(
> + const void *name,
> + size_t length)
> +{
> + /*
> + * MAXNAMELEN includes the trailing null, but (name/length) leave it
> + * out, so use >= for the length check.
> + */
> + if (length >= MAXNAMELEN)
> + return false;
> +
> + /* There shouldn't be any slashes or nulls here */
> + return !memchr(name, '/', length) && !memchr(name, 0, length);
> +}
> diff --git a/fs/xfs/libxfs/xfs_dir2.h b/fs/xfs/libxfs/xfs_dir2.h
> index c3e3f6b813d8..f54244779492 100644
> --- a/fs/xfs/libxfs/xfs_dir2.h
> +++ b/fs/xfs/libxfs/xfs_dir2.h
> @@ -326,5 +326,6 @@ xfs_dir2_leaf_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_leaf *lp)
> unsigned char xfs_dir3_get_dtype(struct xfs_mount *mp, uint8_t filetype);
> void *xfs_dir3_data_endp(struct xfs_da_geometry *geo,
> struct xfs_dir2_data_hdr *hdr);
> +bool xfs_dir2_namecheck(const void *name, size_t length);
>
> #endif /* __XFS_DIR2_H__ */
> diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
> index cd3e4d768a18..a38a22785a1a 100644
> --- a/fs/xfs/scrub/dir.c
> +++ b/fs/xfs/scrub/dir.c
> @@ -129,6 +129,12 @@ xchk_dir_actor(
> goto out;
> }
>
> + /* Does this name make sense? */
> + if (!xfs_dir2_namecheck(name, namelen)) {
> + xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
> + goto out;
> + }
> +
> if (!strncmp(".", name, namelen)) {
> /* If this is "." then check that the inum matches the dir. */
> if (xfs_sb_version_hasftype(&mp->m_sb) && type != DT_DIR)
>
