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author | Dave Chinner <dchinner@redhat.com> | 2022-05-04 12:13:53 +1000 |
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committer | Dave Chinner <david@fromorbit.com> | 2022-05-04 12:13:53 +1000 |
commit | 1eb70f54c445fcbb25817841e774adb3d912f3e8 (patch) | |
tree | e60999e3a3dfcfd97e5dbf6edbecfb620c96043f | |
parent | dc04db2aa7c9307e740d6d0e173085301c173b1a (diff) | |
download | linux-1eb70f54c445fcbb25817841e774adb3d912f3e8.tar.bz2 |
xfs: validate inode fork size against fork format
xfs_repair catches fork size/format mismatches, but the in-kernel
verifier doesn't, leading to null pointer failures when attempting
to perform operations on the fork. This can occur in the
xfs_dir_is_empty() where the in-memory fork format does not match
the size and so the fork data pointer is accessed incorrectly.
Note: this causes new failures in xfs/348 which is testing mode vs
ftype mismatches. We now detect a regular file that has been changed
to a directory or symlink mode as being corrupt because the data
fork is for a symlink or directory should be in local form when
there are only 3 bytes of data in the data fork. Hence the inode
verify for the regular file now fires w/ -EFSCORRUPTED because
the inode fork format does not match the format the corrupted mode
says it should be in.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
-rw-r--r-- | fs/xfs/libxfs/xfs_inode_buf.c | 35 |
1 files changed, 26 insertions, 9 deletions
diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c index 74b82ec80f8e..3b1b63f9d886 100644 --- a/fs/xfs/libxfs/xfs_inode_buf.c +++ b/fs/xfs/libxfs/xfs_inode_buf.c @@ -357,21 +357,38 @@ xfs_dinode_verify_fork( { xfs_extnum_t di_nextents; xfs_extnum_t max_extents; + mode_t mode = be16_to_cpu(dip->di_mode); + uint32_t fork_size = XFS_DFORK_SIZE(dip, mp, whichfork); + uint32_t fork_format = XFS_DFORK_FORMAT(dip, whichfork); di_nextents = xfs_dfork_nextents(dip, whichfork); - switch (XFS_DFORK_FORMAT(dip, whichfork)) { + /* + * For fork types that can contain local data, check that the fork + * format matches the size of local data contained within the fork. + * + * For all types, check that when the size says the should be in extent + * or btree format, the inode isn't claiming it is in local format. + */ + if (whichfork == XFS_DATA_FORK) { + if (S_ISDIR(mode) || S_ISLNK(mode)) { + if (be64_to_cpu(dip->di_size) <= fork_size && + fork_format != XFS_DINODE_FMT_LOCAL) + return __this_address; + } + + if (be64_to_cpu(dip->di_size) > fork_size && + fork_format == XFS_DINODE_FMT_LOCAL) + return __this_address; + } + + switch (fork_format) { case XFS_DINODE_FMT_LOCAL: /* - * no local regular files yet + * No local regular files yet. */ - if (whichfork == XFS_DATA_FORK) { - if (S_ISREG(be16_to_cpu(dip->di_mode))) - return __this_address; - if (be64_to_cpu(dip->di_size) > - XFS_DFORK_SIZE(dip, mp, whichfork)) - return __this_address; - } + if (S_ISREG(mode) && whichfork == XFS_DATA_FORK) + return __this_address; if (di_nextents) return __this_address; break; |