From: "Darrick J. Wong" darrick.wong@oracle.com
commit acf104c2331c1ba2a667e65dd36139d1555b1432 upstream.
Detect file block mappings with a blockcount that's either so large that integer overflows occur or are zero, because neither are valid in the filesystem. Worse yet, attempting directory modifications causes the iext code to trip over the bmbt key handling and takes the filesystem down. We can fix most of this by preventing the bad metadata from entering the incore structures in the first place.
Found by setting blockcount=0 in a directory data fork mapping and watching the fireworks.
Signed-off-by: Darrick J. Wong darrick.wong@oracle.com Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Amir Goldstein amir73il@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/xfs/libxfs/xfs_bmap.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -6229,6 +6229,11 @@ xfs_bmap_validate_extent( xfs_fsblock_t endfsb; bool isrt;
+ if (irec->br_startblock + irec->br_blockcount <= irec->br_startblock) + return __this_address; + if (irec->br_startoff + irec->br_blockcount <= irec->br_startoff) + return __this_address; + isrt = XFS_IS_REALTIME_INODE(ip); endfsb = irec->br_startblock + irec->br_blockcount - 1; if (isrt && whichfork == XFS_DATA_FORK) {