https://bugzilla.kernel.org/show_bug.cgi?id=204371
--- Comment #38 from Christophe Leroy (christophe.le...@c-s.fr) --- Le 30/07/2019 à 20:52, bugzilla-dae...@bugzilla.kernel.org a écrit : > https://bugzilla.kernel.org/show_bug.cgi?id=204371 > > --- Comment #2 from Andrew Morton (a...@linux-foundation.org) --- > (switched to email. Please respond via emailed reply-to-all, not via the > bugzilla web interface). Reply all replies to bugzilla-dae...@bugzilla.kernel.org only. [...] > > cc'ing various people here. Hum ... only got that email through the bugzilla interface, and CC'ed people don't show up. > > I suspect proc_cgroup_show() is innocent and that perhaps > bpf_prepare_filter() had a memory scribble. iirc there has been at > least one recent pretty serious bpf fix applied recently. Can others > please take a look? > > (Seriously - please don't modify this report via the bugzilla web interface!) > Haven't got the original CC'ed list, so please reply with missing Cc's if any. We have well progressed on this case. Erhard made a relation being this "Object padding overwritten" issue arising on any driver, and the presence of the BTRFS driver. Then he was able to bisect the issue to: commit 69d2480456d1baf027a86e530989d7bedd698d5f Author: David Sterba <dste...@suse.com> Date: Fri Jun 29 10:56:44 2018 +0200 btrfs: use copy_page for copying pages instead of memcpy Use the helper that's possibly optimized for full page copies. Signed-off-by: David Sterba <dste...@suse.com> After looking in the code, it has appeared that some of the said "pages" were allocated with "kzalloc()". Using the patch https://patchwork.ozlabs.org/patch/1148033/ Erhard confirmed that some btrfs functions were calling copy_page() with misaligned destinations. copy_page(), at least on powerpc, expects cache aligned destination. The patch https://patchwork.ozlabs.org/patch/1148606/ fixes the issue. Christophe --- L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast. https://www.avast.com/antivirus -- You are receiving this mail because: You are on the CC list for the bug.
