From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id A16E929E05 for ; Thu, 4 Feb 2016 17:03:10 -0600 (CST) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay3.corp.sgi.com (Postfix) with ESMTP id 336E6AC001 for ; Thu, 4 Feb 2016 15:03:10 -0800 (PST) Received: from ipmail06.adl2.internode.on.net (ipmail06.adl2.internode.on.net [150.101.137.129]) by cuda.sgi.com with ESMTP id VpgJtA2GPOcMSDqT for ; Thu, 04 Feb 2016 15:02:56 -0800 (PST) Received: from disappointment.disaster.area ([192.168.1.110] helo=disappointment) by dastard with esmtp (Exim 4.80) (envelope-from ) id 1aRStY-0000D9-ST for xfs@oss.sgi.com; Fri, 05 Feb 2016 10:01:00 +1100 Received: from dave by disappointment with local (Exim 4.86) (envelope-from ) id 1aRStY-0004vc-R6 for xfs@oss.sgi.com; Fri, 05 Feb 2016 10:01:00 +1100 From: Dave Chinner Subject: [PATCH 2/3] metadump: bounds check btree block regions being zeroed Date: Fri, 5 Feb 2016 10:00:57 +1100 Message-Id: <1454626858-17823-3-git-send-email-david@fromorbit.com> In-Reply-To: <1454626858-17823-1-git-send-email-david@fromorbit.com> References: <1454626858-17823-1-git-send-email-david@fromorbit.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com From: Dave Chinner Arkadiusz Miskiewicz reported that metadump was crashing on one of his corrupted filesystems, and the trace indicated that it was zeroing unused regions in inode btree blocks when it failed. The btree block had a corrupt nrecs field, which was resulting in an out of bounds memset() occurring. Ensure that the region being generated for zeroing is within bounds before executing the zeroing. Reported-by: Arkadiusz Miskiewicz Signed-off-by: Dave Chinner --- db/metadump.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/db/metadump.c b/db/metadump.c index a185da5..26a3bd5 100644 --- a/db/metadump.c +++ b/db/metadump.c @@ -246,6 +246,11 @@ write_buf( return seenint() ? -EINTR : 0; } +/* + * We could be processing a corrupt block, so we can't trust any of + * the offsets or lengths to be within the buffer range. Hence check + * carefully! + */ static void zero_btree_node( struct xfs_btree_block *block, @@ -262,10 +267,15 @@ zero_btree_node( char *key_end; nrecs = be16_to_cpu(block->bb_numrecs); + if (nrecs < 0) + return; switch (btype) { case TYP_BMAPBTA: case TYP_BMAPBTD: + if (nrecs > mp->m_bmap_dmxr[1]) + return; + bkp = XFS_BMBT_KEY_ADDR(mp, block, 1); bpp = XFS_BMBT_PTR_ADDR(mp, block, 1, mp->m_bmap_dmxr[1]); zp1 = (char *)&bkp[nrecs]; @@ -274,6 +284,9 @@ zero_btree_node( break; case TYP_INOBT: case TYP_FINOBT: + if (nrecs > mp->m_inobt_mxr[1]) + return; + ikp = XFS_INOBT_KEY_ADDR(mp, block, 1); ipp = XFS_INOBT_PTR_ADDR(mp, block, 1, mp->m_inobt_mxr[1]); zp1 = (char *)&ikp[nrecs]; @@ -282,6 +295,9 @@ zero_btree_node( break; case TYP_BNOBT: case TYP_CNTBT: + if (nrecs > mp->m_alloc_mxr[1]) + return; + akp = XFS_ALLOC_KEY_ADDR(mp, block, 1); app = XFS_ALLOC_PTR_ADDR(mp, block, 1, mp->m_alloc_mxr[1]); zp1 = (char *)&akp[nrecs]; @@ -300,6 +316,11 @@ zero_btree_node( memset(zp2, 0, (char *)block + mp->m_sb.sb_blocksize - zp2); } +/* + * We could be processing a corrupt block, so we can't trust any of + * the offsets or lengths to be within the buffer range. Hence check + * carefully! + */ static void zero_btree_leaf( struct xfs_btree_block *block, @@ -312,20 +333,31 @@ zero_btree_leaf( char *zp; nrecs = be16_to_cpu(block->bb_numrecs); + if (nrecs < 0) + return; switch (btype) { case TYP_BMAPBTA: case TYP_BMAPBTD: + if (nrecs > mp->m_bmap_dmxr[0]) + return; + brp = XFS_BMBT_REC_ADDR(mp, block, 1); zp = (char *)&brp[nrecs]; break; case TYP_INOBT: case TYP_FINOBT: + if (nrecs > mp->m_inobt_mxr[0]) + return; + irp = XFS_INOBT_REC_ADDR(mp, block, 1); zp = (char *)&irp[nrecs]; break; case TYP_BNOBT: case TYP_CNTBT: + if (nrecs > mp->m_alloc_mxr[0]) + return; + arp = XFS_ALLOC_REC_ADDR(mp, block, 1); zp = (char *)&arp[nrecs]; break; -- 2.5.0 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs