From: Gao Xiang <hsiangkao@xxxxxxxxxx> commit bde545295b710bdd13a0fcd4b9fddd2383eeeb3a upstream. 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@xxxxxxxxxx Link: https://lore.kernel.org/r/20210120013016.14071-1-hsiangkao@xxxxxxx Reported-by: syzbot+c68f467cd7c45860e8d4@xxxxxxxxxxxxxxxxxxxxxxxxx Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx> Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/erofs/super.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -158,8 +158,8 @@ static int erofs_read_superblock(struct 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; }