Xorg crashing in pci_device_vgaarb_set_target

[Peter Kasza]

On Tue, Oct 10, 2017 at 05:19:05PM +0000, Adam Jackson wrote:
> On Mon, 2017-10-09 at 13:07 +0200, Peter Kasza wrote:
> > Hi all,
> > 
> > I'm getting itermittent crashes on a vfio enabled machine. I'm not
> > able to recreate it on purpose, but it seems to be occurring when
> > virtualbox VMs and Firefox are running.
> > 
> > From the backtrace I suspect that some bogus parameter is passed to
> > the snprintf call, but other than that I'm not sure.
> > 
> > The crash occurs in libpciaccess - pci_device_vgaarb_set_target. I
> > have the latest release installed (0.13.5).
> > 
> > Program terminated with signal SIGSEGV, Segmentation fault.
> > #0  0x00007f17082667a3 in __GI__IO_default_xsputn () from /usr/lib/libc.so.6
> > [Current thread is 1 (Thread 0x7f170aa11940 (LWP 491))]
> > (gdb) bt
> > #0  0x00007f17082667a3 in __GI__IO_default_xsputn () at /usr/lib/libc.so.6
> > #1  0x00007f1708259b2d in __GI__IO_padn () at /usr/lib/libc.so.6
> > #2  0x00007f1708239938 in vfprintf () at /usr/lib/libc.so.6
> > #3  0x00007f17082efcbb in __vsnprintf_chk () at /usr/lib/libc.so.6
> > #4  0x00007f17082efbe5 in __snprintf_chk () at /usr/lib/libc.so.6
> > #5  0x00007f1709a966b8 in pci_device_vgaarb_set_target () at /usr/lib/libpciaccess.so.0
> > #6  0x00005616427d1fc8 in  ()
> 
> Any chance you can (install debuginfo and) see the rest of this call
> trace? I suspect the value of 'dev' being passed into
> pci_device_vgaarb_set_target is just bogus, but without the call trace
> up through Xorg it's hard to see how that could happen.
> 
> - ajax

Hey,

Thanks for the suggestion. I've compiled a debug version of X. I'll
reply back once I've reproduced the issue with more info.

-- 
Best Regards,
Peter Kasza

http://www.itinsight.hu
peter.kasza at itinsight.hu

()  ascii ribbon campaign - against html e-mail
/\  www.asciiribbon.org   - against proprietary attachments