From: Jan Kara Subject: [PATCH 2/4] ext4: Fix overflows in SEEK_HOLE, SEEK_DATA implementations Date: Wed, 29 May 2013 14:05:31 +0200 Message-ID: <1369829133-4307-3-git-send-email-jack@suse.cz> References: <1369829133-4307-1-git-send-email-jack@suse.cz> Cc: linux-ext4@vger.kernel.org, Jan Kara To: Ted Tso Return-path: Received: from cantor2.suse.de ([195.135.220.15]:52117 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965645Ab3E2MFl (ORCPT ); Wed, 29 May 2013 08:05:41 -0400 In-Reply-To: <1369829133-4307-1-git-send-email-jack@suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: ext4_lblk_t is just u32 so multiplying it by blocksize can easily overflow for files larger than 4 GB. Fix that by properly typing the block offsets before shifting. Signed-off-by: Jan Kara --- fs/ext4/file.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/fs/ext4/file.c b/fs/ext4/file.c index b1b4d51..b19f0a4 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -312,7 +312,7 @@ static int ext4_find_unwritten_pgoff(struct inode *inode, blkbits = inode->i_sb->s_blocksize_bits; startoff = *offset; lastoff = startoff; - endoff = (map->m_lblk + map->m_len) << blkbits; + endoff = (loff_t)(map->m_lblk + map->m_len) << blkbits; index = startoff >> PAGE_CACHE_SHIFT; end = endoff >> PAGE_CACHE_SHIFT; @@ -457,7 +457,7 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize) ret = ext4_map_blocks(NULL, inode, &map, 0); if (ret > 0 && !(map.m_flags & EXT4_MAP_UNWRITTEN)) { if (last != start) - dataoff = last << blkbits; + dataoff = (loff_t)last << blkbits; break; } @@ -468,7 +468,7 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize) ext4_es_find_delayed_extent_range(inode, last, last, &es); if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) { if (last != start) - dataoff = last << blkbits; + dataoff = (loff_t)last << blkbits; break; } @@ -486,7 +486,7 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize) } last++; - dataoff = last << blkbits; + dataoff = (loff_t)last << blkbits; } while (last <= end); mutex_unlock(&inode->i_mutex); @@ -540,7 +540,7 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize) ret = ext4_map_blocks(NULL, inode, &map, 0); if (ret > 0 && !(map.m_flags & EXT4_MAP_UNWRITTEN)) { last += ret; - holeoff = last << blkbits; + holeoff = (loff_t)last << blkbits; continue; } @@ -551,7 +551,7 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize) ext4_es_find_delayed_extent_range(inode, last, last, &es); if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) { last = es.es_lblk + es.es_len; - holeoff = last << blkbits; + holeoff = (loff_t)last << blkbits; continue; } @@ -566,7 +566,7 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize) &map, &holeoff); if (!unwritten) { last += ret; - holeoff = last << blkbits; + holeoff = (loff_t)last << blkbits; continue; } } -- 1.8.1.4