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| author | Darrick J. Wong <darrick.wong@oracle.com> | 2018-01-16 18:54:13 -0800 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2018-01-17 21:00:47 -0800 |
| commit | a5f460b168820335706c0d8cd8c8bc3657f1dd5e (patch) | |
| tree | dda319e41a9af8cacf8599bcb45d4a3cd3ea6ea6 | |
| parent | 55e45429ce3e4ac9dd2bf4937b1a499a69ccc4ca (diff) | |
| download | linux-a5f460b168820335706c0d8cd8c8bc3657f1dd5e.tar.gz linux-a5f460b168820335706c0d8cd8c8bc3657f1dd5e.tar.bz2 linux-a5f460b168820335706c0d8cd8c8bc3657f1dd5e.zip | |
xfs: check that br_blockcount doesn't overflow
xfs_bmbt_irec.br_blockcount is declared as xfs_filblks_t, which is an
unsigned 64-bit integer. Though the bmbt helpers will never set a value
larger than 2^21 (since the underlying on-disk extent record has a
length field that is only 21 bits wide), we should be a little defensive
about checking that a bmbt record doesn't exceed what we're expecting or
overflow into the next AG.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
| -rw-r--r-- | fs/xfs/scrub/bmap.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/fs/xfs/scrub/bmap.c b/fs/xfs/scrub/bmap.c index 2bb3e0c4b4ef..d00282130492 100644 --- a/fs/xfs/scrub/bmap.c +++ b/fs/xfs/scrub/bmap.c @@ -305,6 +305,7 @@ xfs_scrub_bmap_extent( { struct xfs_mount *mp = info->sc->mp; struct xfs_buf *bp = NULL; + xfs_filblks_t end; int error = 0; if (cur) @@ -332,19 +333,23 @@ xfs_scrub_bmap_extent( irec->br_startoff); /* Make sure the extent points to a valid place. */ + if (irec->br_blockcount > MAXEXTLEN) + xfs_scrub_fblock_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); if (irec->br_startblock + irec->br_blockcount <= irec->br_startblock) xfs_scrub_fblock_set_corrupt(info->sc, info->whichfork, irec->br_startoff); + end = irec->br_startblock + irec->br_blockcount - 1; if (info->is_rt && (!xfs_verify_rtbno(mp, irec->br_startblock) || - !xfs_verify_rtbno(mp, irec->br_startblock + - irec->br_blockcount - 1))) + !xfs_verify_rtbno(mp, end))) xfs_scrub_fblock_set_corrupt(info->sc, info->whichfork, irec->br_startoff); if (!info->is_rt && (!xfs_verify_fsbno(mp, irec->br_startblock) || - !xfs_verify_fsbno(mp, irec->br_startblock + - irec->br_blockcount - 1))) + !xfs_verify_fsbno(mp, end) || + XFS_FSB_TO_AGNO(mp, irec->br_startblock) != + XFS_FSB_TO_AGNO(mp, end))) xfs_scrub_fblock_set_corrupt(info->sc, info->whichfork, irec->br_startoff); |