From: Eric Sandeen <sandeen@redhat.com> stable inclusion from stable-v6.6.103 commit d3cc7476b89fb45b7e00874f4f56f6b928467c60 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/8667 CVE: CVE-2025-39835 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=t... -------------------------------- commit ae668cd567a6a7622bc813ee0bb61c42bed61ba7 upstream. ENODATA (aka ENOATTR) has a very specific meaning in the xfs xattr code; namely, that the requested attribute name could not be found. However, a medium error from disk may also return ENODATA. At best, this medium error may escape to userspace as "attribute not found" when in fact it's an IO (disk) error. At worst, we may oops in xfs_attr_leaf_get() when we do: error = xfs_attr_leaf_hasname(args, &bp); if (error == -ENOATTR) { xfs_trans_brelse(args->trans, bp); return error; } because an ENODATA/ENOATTR error from disk leaves us with a null bp, and the xfs_trans_brelse will then null-deref it. As discussed on the list, we really need to modify the lower level IO functions to trap all disk errors and ensure that we don't let unique errors like this leak up into higher xfs functions - many like this should be remapped to EIO. However, this patch directly addresses a reported bug in the xattr code, and should be safe to backport to stable kernels. A larger-scope patch to handle more unique errors at lower levels can follow later. (Note, prior to 07120f1abdff we did not oops, but we did return the wrong error code to userspace.) Signed-off-by: Eric Sandeen <sandeen@redhat.com> Fixes: 07120f1abdff ("xfs: Add xfs_has_attr and subroutines") Cc: stable@vger.kernel.org # v5.9+ Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org> [ Adjust context: removed metadata health tracking calls ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Long Li <leo.lilong@huawei.com> --- fs/xfs/libxfs/xfs_attr_remote.c | 7 +++++++ fs/xfs/libxfs/xfs_da_btree.c | 6 ++++++ 2 files changed, 13 insertions(+) diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c index 54de405cbab5..4d369876487b 100644 --- a/fs/xfs/libxfs/xfs_attr_remote.c +++ b/fs/xfs/libxfs/xfs_attr_remote.c @@ -418,6 +418,13 @@ xfs_attr_rmtval_get( dblkcnt = XFS_FSB_TO_BB(mp, map[i].br_blockcount); error = xfs_buf_read(mp->m_ddev_targp, dblkno, dblkcnt, 0, &bp, &xfs_attr3_rmt_buf_ops); + /* + * ENODATA from disk implies a disk medium failure; + * ENODATA for xattrs means attribute not found, so + * disambiguate that here. + */ + if (error == -ENODATA) + error = -EIO; if (error) return error; diff --git a/fs/xfs/libxfs/xfs_da_btree.c b/fs/xfs/libxfs/xfs_da_btree.c index 6b5abbcb61c6..6daf13898f33 100644 --- a/fs/xfs/libxfs/xfs_da_btree.c +++ b/fs/xfs/libxfs/xfs_da_btree.c @@ -2676,6 +2676,12 @@ xfs_da_read_buf( error = xfs_trans_read_buf_map(mp, tp, mp->m_ddev_targp, mapp, nmap, 0, &bp, ops); + /* + * ENODATA from disk implies a disk medium failure; ENODATA for + * xattrs means attribute not found, so disambiguate that here. + */ + if (error == -ENODATA && whichfork == XFS_ATTR_FORK) + error = -EIO; if (error) goto out_free; -- 2.39.2