4.9-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. 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> 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 @@ -1424,6 +1424,8 @@ int sanity_check_ckpt(struct f2fs_sb_inf 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); @@ -1435,6 +1437,20 @@ int sanity_check_ckpt(struct f2fs_sb_inf 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;