[RESEND v4 2/6] remoteproc: debugfs: Add ability to boot remote processor using debugfs

Bjorn Andersson bjorn at kryo.se
Thu Dec 3 13:22:50 PST 2015


On Thu, Dec 3, 2015 at 1:12 PM, Arnd Bergmann <arnd at arndb.de> wrote:
> On Thursday 03 December 2015 17:28:30 Lee Jones wrote:
>> >
>> > Ah, interesting. I haven't tried myself, and just tried to read the
>> > code. Maybe glibc already catches zero-length writes before it gets
>> > into the kernel, or I just missed the part of the syscall that checks
>> > for this.
>>
>> Glibc is responsible indeed:
>>
>>   http://osxr.org/glibc/source/io/write.c
>
> Ok, so an attacker can force the stack overflow by calling
> syscall(__NR_write, fd, p, 0) if that has any potential value,
> but normal users won't hit this case.
>

It seems glibc might be the only libc implementation with this protection.

Regards,
Bjorn



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