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Fri, 16 Jan 2026 07:24:29 -0800 (PST) Date: Fri, 16 Jan 2026 07:24:27 -0800 In-Reply-To: <696a546a.050a0220.58bed.0056.GAE@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <696a546a.050a0220.58bed.0056.GAE@google.com> Message-ID: Subject: Re: [syzbot] [kvm?] BUG: unable to handle kernel paging request in kvm_gmem_get_folio From: Sean Christopherson To: syzbot Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="us-ascii" On Fri, Jan 16, 2026, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 9b7977f9e39b Add linux-next specific files for 20260115 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=10585522580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=9c0b39f55c418575 > dashboard link: https://syzkaller.appspot.com/bug?extid=6f16df7b5a49f0e01b18 > compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/32edced7b806/disk-9b7977f9.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/dec5450e284a/vmlinux-9b7977f9.xz > kernel image: https://storage.googleapis.com/syzbot-assets/65783c99fb65/bzImage-9b7977f9.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+6f16df7b5a49f0e01b18@syzkaller.appspotmail.com > > BUG: unable to handle page fault for address: fffffffffffffffc > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD e143067 P4D e143067 PUD e145067 PMD 0 > Oops: Oops: 0000 [#1] SMP KASAN PTI > CPU: 0 UID: 0 PID: 10212 Comm: syz.7.1148 Tainted: G L syzkaller #0 PREEMPT(full) > Tainted: [L]=SOFTLOCKUP > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 > RIP: 0010:const_folio_flags include/linux/page-flags.h:351 [inline] > RIP: 0010:folio_test_head include/linux/page-flags.h:844 [inline] > RIP: 0010:folio_test_large include/linux/page-flags.h:865 [inline] > RIP: 0010:folio_order include/linux/mm.h:1248 [inline] > RIP: 0010:kvm_gmem_get_folio+0x12e/0x240 virt/kvm/guest_memfd.c:147 Too slow, syzbot! https://lore.kernel.org/all/aWk9PusYNW0iADuD@google.com #syz invalid