Commit bde54529 authored by Gao Xiang's avatar Gao Xiang
Browse files

erofs: fix shift-out-of-bounds of blkszbits 

syzbot generated a crafted bitszbits which can be shifted
out-of-bounds[1]. So directly print unsupported blkszbits
instead of blksize.

[1] https://lore.kernel.org/r/000000000000c72ddd05b9444d2f@google.com

Link: https://lore.kernel.org/r/20210120013016.14071-1-hsiangkao@aol.com


Reported-by: default avatar <syzbot+c68f467cd7c45860e8d4@syzkaller.appspotmail.com>
Reviewed-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarGao Xiang <hsiangkao@redhat.com>
parent 19c329f6

fs/erofs/super.c

+2 −2
Original line number Diff line number Diff line
@@ -158,8 +158,8 @@ static int erofs_read_superblock(struct super_block *sb) 
	blkszbits = dsb->blkszbits;

	/* 9(512 bytes) + LOG_SECTORS_PER_BLOCK == LOG_BLOCK_SIZE */

	if (blkszbits != LOG_BLOCK_SIZE) {

		erofs_err(sb, "blksize %u isn't supported on this platform",

			  1 << blkszbits);

		erofs_err(sb, "blkszbits %u isn't supported on this platform",

			  blkszbits);

		goto out;

	}