> I don't have a device large enough to test for signedness errors, since
> passing
> huge values for start and len never make it past the i_size_read check.
> However, I do see that I forgot to check the padding values, so I'll update
> that.
Then do you want to at least consider converting end to be of type loff_t to
match the type of value returned by i_get_size() and the type of the value
passed to truncate_inode_pages_range()? Then you only need one additional
check, something like:
/* Check for an overflow when adding start+len into end */
if (start > (uint64_t)LLONG_MAX - len)
return -EINVAL;
Looking at the maximum values if we have start=0 and
len=(uint64_t)LLONG_MAX we would still continue but
len=(uint64_t)LLONG_MAX+1 would return -EINVAL. Similarly for
start=(uint64_t)LLONG_MAX and len=0 it would continue
but start=(uint64_t)LLONG_MAX+1 would return -EINVAL and that
should allow start + len to be safely added and stored into an loff_t without
overflow. With this check start+len can never be more than (uint64_t)LLONG_MAX
which would make the other checks I suggested to ensure that neither start or
end
were more than (uint64_t)LLONG_MAX unnecessary.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
