diff mbox series

[-next,RFC] ext2: Add check if block is step over super block

Message ID 20211101093351.1164368-1-yebin10@huawei.com
State Not Applicable
Headers show
Series [-next,RFC] ext2: Add check if block is step over super block | expand

Commit Message

yebin (H) Nov. 1, 2021, 9:33 a.m. UTC
We got an issue that super block is allocated by file system when run syzkaller
test. We add debug information find that origin image super block's block bitmap
is zero. There isn't check whether block is step over super block in ext2_new_blocks.

In order not to make things worse, we'd better to add check if block step over
super block when new blocks.

Signed-off-by: Ye Bin <yebin10@huawei.com>
---
 fs/ext2/balloc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
index c17ccc19b938..b93d52e6a17a 100644
--- a/fs/ext2/balloc.c
+++ b/fs/ext2/balloc.c
@@ -1376,7 +1376,8 @@  ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal,
 	    in_range(ret_block, le32_to_cpu(gdp->bg_inode_table),
 		      EXT2_SB(sb)->s_itb_per_group) ||
 	    in_range(ret_block + num - 1, le32_to_cpu(gdp->bg_inode_table),
-		      EXT2_SB(sb)->s_itb_per_group)) {
+		      EXT2_SB(sb)->s_itb_per_group) ||
+	    in_range(EXT2_SB(sb)->s_sb_block, ret_block, num)) {
 		ext2_error(sb, "ext2_new_blocks",
 			    "Allocating block in system zone - "
 			    "blocks from "E2FSBLK", length %lu",