Thanks for your reply.
I agree that extra allocation in match_number() and match_u64int() may
be unnecessary.
Thanks,
Jia-Ju Bai
On 2017/10/7 9:37, Linus Torvalds wrote:
On Fri, Oct 6, 2017 at 6:20 PM, Jia-Ju Bai <baijiaju1990@xxxxxxx> wrote:
To fix it, GFP_KERNEL is replaced with GFP_ATOMIC.
This bug is found by my static analysis tool and my code review.
I'm not saying your patch is wrong, but it's a shame that we do that
extra allocation in match_number() and match_u64int(), and that we
don't have anything that is just size-limited.
And there really isn't anything saying that we shouldn't do the same
silly thing to match_u64int(). Maybe we don't have any actual users
that need it for now, but still..
Oh well.
I do wonder if we shouldn't just use something like
"skip leading zeroes, copy to size-limited stack location instead"
because the input length really *is* limited once you skip leading
zeroes (and whatever base marker we have). We might have at most a
64-bit value in octal, so 22 bytes max.
But I guess just changing the two GFP_KERNEL's to GFP_ATOMIC is much simpler.
Linus
