Commit e5126de1 authored by Yue Hu's avatar Yue Hu Committed by Gao Xiang
Browse files

erofs: fix general protection fault when reading fragment 

As syzbot reported [1], the fragment feature sb flag is not set, so
packed_inode != NULL needs to be checked in z_erofs_read_fragment().

[1] https://lore.kernel.org/all/0000000000002e7a8905eb841ddd@google.com/



Reported-by: default avatar <syzbot+3faecbfd845a895c04cb@syzkaller.appspotmail.com>
Fixes: b15b2e30 ("erofs: support on-disk compressed fragments data")
Signed-off-by: default avatarYue Hu <huyue2@coolpad.com>
Reviewed-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20221021085325.25788-1-zbestahu@gmail.com


Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent f0c4d9fc

fs/erofs/zdata.c

+3 −0
Original line number Diff line number Diff line
@@ -660,6 +660,9 @@ static int z_erofs_read_fragment(struct inode *inode, erofs_off_t pos, 
	u8 *src, *dst;

	unsigned int i, cnt;



	if (!packed_inode)

		return -EFSCORRUPTED;



	pos += EROFS_I(inode)->z_fragmentoff;

	for (i = 0; i < len; i += cnt) {

		cnt = min_t(unsigned int, len - i,