From f4020438fab05364018c91f7e02ebdd192085933 Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Wed, 26 Aug 2020 14:11:58 -0700 Subject: xfs: fix boundary test in xfs_attr_shortform_verify The boundary test for the fixed-offset parts of xfs_attr_sf_entry in xfs_attr_shortform_verify is off by one, because the variable array at the end is defined as nameval[1] not nameval[]. Hence we need to subtract 1 from the calculation. This can be shown by: # touch file # setfattr -n root.a file and verifications will fail when it's written to disk. This only matters for a last attribute which has a single-byte name and no value, otherwise the combination of namelen & valuelen will push endp further out and this test won't fail. Fixes: 1e1bbd8e7ee06 ("xfs: create structure verifier function for shortform xattrs") Signed-off-by: Eric Sandeen Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- fs/xfs/libxfs/xfs_attr_leaf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'fs/xfs/libxfs/xfs_attr_leaf.c') diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c index 8623c815164a..383b08f2ac61 100644 --- a/fs/xfs/libxfs/xfs_attr_leaf.c +++ b/fs/xfs/libxfs/xfs_attr_leaf.c @@ -1036,8 +1036,10 @@ xfs_attr_shortform_verify( * struct xfs_attr_sf_entry has a variable length. * Check the fixed-offset parts of the structure are * within the data buffer. + * xfs_attr_sf_entry is defined with a 1-byte variable + * array at the end, so we must subtract that off. */ - if (((char *)sfep + sizeof(*sfep)) >= endp) + if (((char *)sfep + sizeof(*sfep) - 1) >= endp) return __this_address; /* Don't allow names with known bad length. */ -- cgit v1.2.3 From 125eac243806e021f33a1fdea3687eccbb9f7636 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Wed, 26 Aug 2020 14:12:18 -0700 Subject: xfs: initialize the shortform attr header padding entry Don't leak kernel memory contents into the shortform attr fork. Signed-off-by: Darrick J. Wong Reviewed-by: Eric Sandeen Reviewed-by: Dave Chinner Reviewed-by: Christoph Hellwig --- fs/xfs/libxfs/xfs_attr_leaf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/xfs/libxfs/xfs_attr_leaf.c') diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c index 383b08f2ac61..305d4bc07337 100644 --- a/fs/xfs/libxfs/xfs_attr_leaf.c +++ b/fs/xfs/libxfs/xfs_attr_leaf.c @@ -653,8 +653,8 @@ xfs_attr_shortform_create( ASSERT(ifp->if_flags & XFS_IFINLINE); } xfs_idata_realloc(dp, sizeof(*hdr), XFS_ATTR_FORK); - hdr = (xfs_attr_sf_hdr_t *)ifp->if_u1.if_data; - hdr->count = 0; + hdr = (struct xfs_attr_sf_hdr *)ifp->if_u1.if_data; + memset(hdr, 0, sizeof(*hdr)); hdr->totsize = cpu_to_be16(sizeof(*hdr)); xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_ADATA); } -- cgit v1.2.3