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([2001:b07:6468:f312:541f:a977:4b60:6802]) by smtp.gmail.com with ESMTPSA id c1sm11635129wrs.24.2019.12.05.02.22.21 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 05 Dec 2019 02:22:23 -0800 (PST) Subject: Re: KASAN: slab-out-of-bounds Read in fbcon_get_font To: Dmitry Vyukov Cc: syzbot , Andrey Ryabinin , Bartlomiej Zolnierkiewicz , Daniel Thompson , Daniel Vetter , DRI , ghalat@redhat.com, Gleb Natapov , gwshan@linux.vnet.ibm.com, "H. Peter Anvin" , James Morris , kasan-dev , KVM list , Linux Fbdev development list , LKML , linux-security-module , Maarten Lankhorst , Ingo Molnar , Michael Ellerman , Tetsuo Handa , Russell Currey , Sam Ravnborg , "Serge E. Hallyn" , stewart@linux.vnet.ibm.com, syzkaller-bugs , Kentaro Takeda , Thomas Gleixner , the arch/x86 maintainers References: <0000000000003e640e0598e7abc3@google.com> <41c082f5-5d22-d398-3bdd-3f4bf69d7ea3@redhat.com> From: Paolo Bonzini Message-ID: Date: Thu, 5 Dec 2019 11:22:20 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-MC-Unique: veNGirruOWClZ7j3vKdIbw-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On 05/12/19 11:16, Dmitry Vyukov wrote: > On Thu, Dec 5, 2019 at 11:13 AM Paolo Bonzini wrote: >> >> On 04/12/19 22:41, syzbot wrote: >>> syzbot has bisected this bug to: >>> >>> commit 2de50e9674fc4ca3c6174b04477f69eb26b4ee31 >>> Author: Russell Currey >>> Date: Mon Feb 8 04:08:20 2016 +0000 >>> >>> powerpc/powernv: Remove support for p5ioc2 >>> >>> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=127a042ae00000 >>> start commit: 76bb8b05 Merge tag 'kbuild-v5.5' of >>> git://git.kernel.org/p.. >>> git tree: upstream >>> final crash: https://syzkaller.appspot.com/x/report.txt?x=117a042ae00000 >>> console output: https://syzkaller.appspot.com/x/log.txt?x=167a042ae00000 >>> kernel config: https://syzkaller.appspot.com/x/.config?x=dd226651cb0f364b >>> dashboard link: >>> https://syzkaller.appspot.com/bug?extid=4455ca3b3291de891abc >>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11181edae00000 >>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=105cbb7ae00000 >>> >>> Reported-by: syzbot+4455ca3b3291de891abc@syzkaller.appspotmail.com >>> Fixes: 2de50e9674fc ("powerpc/powernv: Remove support for p5ioc2") >>> >>> For information about bisection process see: >>> https://goo.gl/tpsmEJ#bisection >>> >> >> Why is everybody being CC'd, even if the bug has nothing to do with the >> person's subsystem? > > The To list should be intersection of 2 groups of emails: result of > get_maintainers.pl on the file identified as culprit in the crash > message + emails extracted from the bisected to commit. Ah, and because the machine is a KVM guest, kvm_wait appears in a lot of backtrace and I get to share syzkaller's joy every time. :) This bisect result is bogus, though Tetsuo found the bug anyway. Perhaps you can exclude commits that only touch architectures other than x86? Paolo