UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

xfs: check magic numbers in dir3 leaf verifier first 

Calling xfs_dir3_leaf_hdr_from_disk() in a verifier before
validating the magic numbers in the buffer results in ASSERT
failures due to mismatching magic numbers when a corruption occurs.
Seeing as the verifier is supposed to catch the corruption and pass
it back to the caller, having the verifier assert fail on error
defeats the purpose of detecting the errors in the first place.

Check the magic numbers direct from the buffer before decoding the
header.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
This commit is contained in:
Dave Chinner 2013-09-03 10:06:58 +10:00 committed by Ben Myers
parent a30b036797
commit 0f295a214b
1 changed files with 13 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
fs/xfs/xfs_dir2_leaf.c
View File

@ -180,6 +180,11 @@ xfs_dir3_leaf_check_int(
return true;
}
/*
* We verify the magic numbers before decoding the leaf header so that on debug
* kernels we don't get assertion failures in xfs_dir3_leaf_hdr_from_disk() due
* to incorrect magic numbers.
*/
static bool
xfs_dir3_leaf_verify(
struct xfs_buf *bp,
@ -191,24 +196,25 @@ xfs_dir3_leaf_verify(
ASSERT(magic == XFS_DIR2_LEAF1_MAGIC || magic == XFS_DIR2_LEAFN_MAGIC);
xfs_dir3_leaf_hdr_from_disk(&leafhdr, leaf);
if (xfs_sb_version_hascrc(&mp->m_sb)) {
struct xfs_dir3_leaf_hdr *leaf3 = bp->b_addr;
__uint16_t magic3;
if ((magic == XFS_DIR2_LEAF1_MAGIC &&
leafhdr.magic != XFS_DIR3_LEAF1_MAGIC) ||
(magic == XFS_DIR2_LEAFN_MAGIC &&
leafhdr.magic != XFS_DIR3_LEAFN_MAGIC))
magic3 = (magic == XFS_DIR2_LEAF1_MAGIC) ? XFS_DIR3_LEAF1_MAGIC
: XFS_DIR3_LEAFN_MAGIC;
if (leaf3->info.hdr.magic != cpu_to_be16(magic3))
return false;
if (!uuid_equal(&leaf3->info.uuid, &mp->m_sb.sb_uuid))
return false;
if (be64_to_cpu(leaf3->info.blkno) != bp->b_bn)
return false;
} else {
if (leafhdr.magic != magic)
if (leaf->hdr.info.magic != cpu_to_be16(magic))
return false;
}
xfs_dir3_leaf_hdr_from_disk(&leafhdr, leaf);
return xfs_dir3_leaf_check_int(mp, &leafhdr, leaf);
}