On Wed, Nov 20, 2024 at 08:25:57AM +0000, Ulrich Teichert wrote: > Hi Dominique & all, > > >Salvatore Bonaccorso wrote on Wed, Nov 20, 2024 at 08:01:23AM +0100: > >> Interestigly there is another report in Debian which identifies the > >> backport of upstream commit 44c76825d6eefee9eb7ce06c38e1a6632ac7eb7d > >> to cause issues in the 6.1.y series: > >> > >> https://bugs.debian.org/1085762 > >> https://lore.kernel.org/regressions/18f34d636390454180240e6a61af9217@xxxxxxxxx/T/#u > > >Thanks for the heads up! > > >This would appear to be the same bug (running qemu-aarch64 in user mode > >on an x86 machine) ? > >I've added Ulrich in recipients to confirm he's using qemu-user-static > >like I was. > > pbuilder uses qemu inside the ARM64 chroot, yes. I don't know which variety of qemu, though. > > >Shame I didn't notice all his work, that would have saved me some > >time :) > > Well, at least we now have confirmation from two different git bisects done by > two different developers, pointing to the same commit ;-) It seems like the correct first step is to revert the brk change. It's still not clear to me why the change is causing a problem -- I assume it is colliding with some other program area. Is the problem strictly with qemu-user-static? (i.e. it was GCC running in qemu-user-static so the crash is qemu, not GCC) That should help me narrow down the issue. There must be some built-in assumption. And it's aarch64 within x86_64 where it happens (is the program within qemu also aarch64 or is it arm32)? Is there an simple reproducer? -Kees -- Kees Cook
