[PATCH] f2fs-tools: fix overflow bug of start_sector when computing zone_align_start_offset

From: Yunlong Song
Date: Sat May 26 2018 - 04:10:07 EST


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@xxxxxxxxxx>
---
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