From: Zheng Liu Subject: Re: [PATCH 2/4] ext4: Fix overflows in SEEK_HOLE, SEEK_DATA implementations Date: Wed, 29 May 2013 21:51:17 +0800 Message-ID: <20130529135117.GA4476@gmail.com> References: <1369829133-4307-1-git-send-email-jack@suse.cz> <1369829133-4307-3-git-send-email-jack@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ted Tso , linux-ext4@vger.kernel.org To: Jan Kara Return-path: Received: from mail-pb0-f43.google.com ([209.85.160.43]:53053 "EHLO mail-pb0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965945Ab3E2NdS (ORCPT ); Wed, 29 May 2013 09:33:18 -0400 Received: by mail-pb0-f43.google.com with SMTP id ma3so9270755pbc.16 for ; Wed, 29 May 2013 06:33:18 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1369829133-4307-3-git-send-email-jack@suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, May 29, 2013 at 02:05:31PM +0200, Jan Kara wrote: > 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 Ah, it's my fault. Thanks for fixing this. Reviewed-by: Zheng Liu - Zheng > --- > 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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html