Re: [PATCH] vmcore: prevent PT_NOTE p_memsz overflow during header update

[Eric W. Biederman]

Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> writes:

> On Sat, 1 Feb 2014 01:07:29 +0000 "Pearson, Greg" <greg.pearson@xxxxxx> wrote:
>
>> As far as I know the only consequence of dropping a PT_NOTE entry is 
>> that it would not be available in the crash dump for use in debugging. 
>> I'm not sure how important this data might be for triage. I'm guessing 
>> that in cases where one of these strange PT_NOTE entries shows up with a 
>> size that causes an overflow it probably isn't even a real PT_NOTE entry 
>> so dropping it won't matter, but that's a guess at this point since I'm 
>> still trying to figure out how the bogus entries were created.
>
> Can we detect the crazy-huge notes, skip them and then proceed with
> the following sanely-sized ones?

The only way we can have following sanely-sized notes is if they are in
a separate note segment (one of our extensions for kdump and
/proc/vmcore merges them together).

Eric
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