On Tue, Jul 25, 2023 at 08:03:16PM +0300, Dan Carpenter wrote:
> The bug is the error handling:
>
> if (tmp < nr_bytes) {
>
> "tmp" can hold negative error codes but because "nr_bytes" is type
> size_t the negative error codes are treated as very high positive
> values (success). Fix this by changing "nr_bytes" to type ssize_t. The
> "nr_bytes" variable is used to store values between 1 and PAGE_SIZE and
> they can fit in ssize_t without any issue.
>
> Fixes: 5d8de293c224 ("vmcore: convert copy_oldmem_page() to take an iov_iter")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
