[PATCH 4.12 104/196] f2fs: sanity check checkpoint segno and blkoff

From: Greg Kroah-Hartman
Date: Tue Jul 25 2017 - 15:39:26 EST


4.12-stable review patch. If anyone has any objections, please let me know.

------------------

From: Jin Qian <jinqian@xxxxxxxxxx>

commit 15d3042a937c13f5d9244241c7a9c8416ff6e82a upstream.

Make sure segno and blkoff read from raw image are valid.

Signed-off-by: Jin Qian <jinqian@xxxxxxxxxx>
[Jaegeuk Kim: adjust minor coding style]
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/f2fs/super.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1521,6 +1521,8 @@ int sanity_check_ckpt(struct f2fs_sb_inf
struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
unsigned int ovp_segments, reserved_segments;
+ unsigned int main_segs, blocks_per_seg;
+ int i;

total = le32_to_cpu(raw_super->segment_count);
fsmeta = le32_to_cpu(raw_super->segment_count_ckpt);
@@ -1542,6 +1544,20 @@ int sanity_check_ckpt(struct f2fs_sb_inf
return 1;
}

+ main_segs = le32_to_cpu(raw_super->segment_count_main);
+ blocks_per_seg = sbi->blocks_per_seg;
+
+ for (i = 0; i < NR_CURSEG_NODE_TYPE; i++) {
+ if (le32_to_cpu(ckpt->cur_node_segno[i]) >= main_segs ||
+ le16_to_cpu(ckpt->cur_node_blkoff[i]) >= blocks_per_seg)
+ return 1;
+ }
+ for (i = 0; i < NR_CURSEG_DATA_TYPE; i++) {
+ if (le32_to_cpu(ckpt->cur_data_segno[i]) >= main_segs ||
+ le16_to_cpu(ckpt->cur_data_blkoff[i]) >= blocks_per_seg)
+ return 1;
+ }
+
if (unlikely(f2fs_cp_error(sbi))) {
f2fs_msg(sbi->sb, KERN_ERR, "A bug case: need to run fsck");
return 1;