From e5d7d51b340aac0f4cc56677eb8d29d4e164c58c Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Fri, 1 Feb 2019 09:08:54 -0800 Subject: [PATCH] xfs: check directory name validity Check directory entry names for invalid characters. Signed-off-by: Darrick J. Wong Reviewed-by: Brian Foster --- 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) -- 2.45.2