Re: [Qemu-devel] [qemu-s390x] [PATCH v3] loader: Check access size when calling rom_ptr() to avoid crashes

[Thomas Huth <thuth@redhat.com>]

On 26.06.2018 10:40, Cornelia Huck wrote:
> On Fri, 15 Jun 2018 11:49:05 +0200
> Thomas Huth <thuth@redhat.com> wrote:
> 
>> The rom_ptr() function allows direct access to the ROM blobs that we
>> load during startup. However, there are currently no checks for the
>> size of the accesses, so it's currently possible to crash QEMU for
>> example with:
>>
>> $ echo "Insane in the mainframe" > /tmp/test.txt
>> $ s390x-softmmu/qemu-system-s390x -kernel /tmp/test.txt -append xyz
>> Segmentation fault (core dumped)
>> $ s390x-softmmu/qemu-system-s390x -kernel /tmp/test.txt -initrd /tmp/test.txt
>> Segmentation fault (core dumped)
>> $ echo -n HdrS > /tmp/hdr.txt
>> $ sparc64-softmmu/qemu-system-sparc64 -kernel /tmp/hdr.txt -initrd /tmp/hdr.txt
>> Segmentation fault (core dumped)
>>
>> We need a possibility to check the size of the ROM area that we want
>> to access, thus let's add a size parameter to the rom_ptr() function
>> to avoid these problems.
>>
>> Signed-off-by: Thomas Huth <thuth@redhat.com>
> 
> Grmpf, this conflicts with "s390/ipl: fix ipl with -no-reboot" in
> s390-next... do you want to rebase it?

Really? Where is the conflict? I can rebase my patch to your s390-next
branch, but the patch looks identical after that rebase. As far as I can
see, the patches only change different parts of the ipl.c file.

 Thomas