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From:   Yunlong Song <yunlong.song@huawei.com>
To:     <jaegeuk@kernel.org>, <chao@kernel.org>, <yuchao0@huawei.com>,
        <yunlong.song@icloud.com>, <yunlong.song@huawei.com>
CC:     <miaoxie@huawei.com>, <bintian.wang@huawei.com>,
        <shengyong1@huawei.com>, <heyunlei@huawei.com>,
        <linux-f2fs-devel@lists.sourceforge.net>,
        <linux-kernel@vger.kernel.org>
Subject: [PATCH] f2fs-tools: fix overflow bug of start_sector when computing zone_align_start_offset
Date:   Sat, 26 May 2018 16:09:49 +0800
Message-ID: <1527322189-114752-1-git-send-email-yunlong.song@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

zone_align_start_offset should be u64, but config.start_sector is u32,
so it may be overflow when computing zone_align_start_offset.

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
---
 fsck/resize.c      | 7 ++++---
 mkfs/f2fs_format.c | 4 ++--
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/fsck/resize.c b/fsck/resize.c
index d285dd7..8ac7d45 100644
--- a/fsck/resize.c
+++ b/fsck/resize.c
@@ -11,7 +11,8 @@
 
 static int get_new_sb(struct f2fs_super_block *sb)
 {
-	u_int32_t zone_size_bytes, zone_align_start_offset;
+	u_int32_t zone_size_bytes;
+	u_int64_t zone_align_start_offset;
 	u_int32_t blocks_for_sit, blocks_for_nat, blocks_for_ssa;
 	u_int32_t sit_segments, nat_segments, diff, total_meta_segments;
 	u_int32_t total_valid_blks_available;
@@ -27,10 +28,10 @@ static int get_new_sb(struct f2fs_super_block *sb)
 
 	zone_size_bytes = segment_size_bytes * segs_per_zone;
 	zone_align_start_offset =
-		(c.start_sector * c.sector_size +
+		((u_int64_t) c.start_sector * c.sector_size +
 		2 * F2FS_BLKSIZE + zone_size_bytes - 1) /
 		zone_size_bytes * zone_size_bytes -
-		c.start_sector * c.sector_size;
+		(u_int64_t) c.start_sector * c.sector_size;
 
 	set_sb(segment_count, (c.target_sectors * c.sector_size -
 				zone_align_start_offset) / segment_size_bytes /
diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
index 0a99a77..f045e23 100644
--- a/mkfs/f2fs_format.c
+++ b/mkfs/f2fs_format.c
@@ -212,10 +212,10 @@ static int f2fs_prepare_super_block(void)
 	set_sb(block_count, c.total_sectors >> log_sectors_per_block);
 
 	zone_align_start_offset =
-		(c.start_sector * c.sector_size +
+		((u_int64_t) c.start_sector * c.sector_size +
 		2 * F2FS_BLKSIZE + zone_size_bytes - 1) /
 		zone_size_bytes * zone_size_bytes -
-		c.start_sector * c.sector_size;
+		(u_int64_t) c.start_sector * c.sector_size;
 
 	if (c.start_sector % c.sectors_per_blk) {
 		MSG(1, "\t%s: Align start sector number to the page unit\n",
-- 
1.8.5.2