From a5f460b168820335706c0d8cd8c8bc3657f1dd5e Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Tue, 16 Jan 2018 18:54:13 -0800 Subject: [PATCH] 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 Reviewed-by: Dave Chinner --- fs/xfs/scrub/bmap.c | 13 +++++++++---- 1 file 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);