Messages in this thread | | | From | Linus Torvalds <> | Date | Fri, 6 Oct 2017 18:37:11 -0700 | Subject | Re: [PATCH] ext2/super: Fix a possible sleep-in-atomic bug in parse_options |
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On Fri, Oct 6, 2017 at 6:20 PM, Jia-Ju Bai <baijiaju1990@163.com> 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
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