From: Jin Qian <jinqian@xxxxxxxxxxx>
commit 15d3042a937c13f5d9244241c7a9c8416ff6e82a upstream.
Make sure segno and blkoff read from raw image are valid.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jin Qian <jinqian@xxxxxxxxxx>
[Jaegeuk Kim: adjust minor coding style]
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
[AmitP: Found in Android Security bulletin for Aug'17, fixes CVE-2017-10663]
Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
---
fs/f2fs/super.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 86e1cb899957..4f666368aa85 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1078,6 +1078,8 @@ static int sanity_check_ckpt(struct f2fs_sb_info *sbi)
unsigned int total, fsmeta;
struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+ 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);
@@ -1089,6 +1091,20 @@ static int sanity_check_ckpt(struct f2fs_sb_info *sbi)
if (unlikely(fsmeta >= total))
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;
--
2.7.4