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AJvYcCXwn8Wv4ifEx45qufwLBGCN5AlmQa3R6iDIxFVXqfDwpMqIKHshFShgLmf+iVK/1vxiL71tKCDuCwV+Wh2rn3DLNHuCCb2uSBCbF4Dp X-Gm-Message-State: AOJu0Yx/ky01PXxGh2y91/uDK/TS2yGbTC+XbAsnNKnEG5WVcIfl4HFM 7P2m1q2MvVlQ5ECtw4/frIvy6gYBdY8L4eaqDWYLvY2u38TPj6m2TR4IkBlG2+G/frXAx+8xkx5 7yQ== X-Google-Smtp-Source: AGHT+IEYND1PzwG+trb6qEOFjAgFLtPajKkdXKu35+GF/BKB06GW3IjOMKfRXPmI0fLXY+f/pgrw1aNTVDg= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:90a:9483:b0:299:1e3:b566 with SMTP id s3-20020a17090a948300b0029901e3b566mr172803pjo.1.1708523782460; Wed, 21 Feb 2024 05:56:22 -0800 (PST) Date: Wed, 21 Feb 2024 05:56:20 -0800 In-Reply-To: <000000000000647d640611db8789@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <000000000000647d640611db8789@google.com> Message-ID: Subject: Re: [syzbot] [kvm?] KMSAN: uninit-value in em_ret_near_imm From: Sean Christopherson To: syzbot Cc: bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, pbonzini@redhat.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, x86@kernel.org Content-Type: text/plain; charset="us-ascii" On Tue, Feb 20, 2024, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 0f1dd5e91e2b Merge tag 'sound-6.8-rc5' of git://git.kernel.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=17bec778180000 > kernel config: https://syzkaller.appspot.com/x/.config?x=e3dd779fba027968 > dashboard link: https://syzkaller.appspot.com/bug?extid=c9aca2253922f806a75a > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/b6e52e101a62/disk-0f1dd5e9.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/64025c9168bf/vmlinux-0f1dd5e9.xz > kernel image: https://storage.googleapis.com/syzbot-assets/491e1a922dc9/bzImage-0f1dd5e9.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+c9aca2253922f806a75a@syzkaller.appspotmail.com > > ===================================================== > BUG: KMSAN: uninit-value in assign_eip_near arch/x86/kvm/emulate.c:829 [inline] > BUG: KMSAN: uninit-value in em_ret_near_imm+0x13c/0x580 arch/x86/kvm/emulate.c:3192 > assign_eip_near arch/x86/kvm/emulate.c:829 [inline] > em_ret_near_imm+0x13c/0x580 arch/x86/kvm/emulate.c:3192 > x86_emulate_insn+0x1d87/0x5880 arch/x86/kvm/emulate.c:5292 > x86_emulate_instruction+0x13c9/0x30a0 arch/x86/kvm/x86.c:9175 > kvm_emulate_instruction arch/x86/kvm/x86.c:9255 [inline] > complete_emulated_io arch/x86/kvm/x86.c:11212 [inline] > complete_emulated_mmio+0x70b/0x8b0 arch/x86/kvm/x86.c:11272 > kvm_arch_vcpu_ioctl_run+0x1837/0xb890 arch/x86/kvm/x86.c:11384 > kvm_vcpu_ioctl+0xbfc/0x1770 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4441 > vfs_ioctl fs/ioctl.c:51 [inline] > __do_sys_ioctl fs/ioctl.c:871 [inline] > __se_sys_ioctl+0x225/0x410 fs/ioctl.c:857 > __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:857 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x63/0x6b > > Local variable eip created at: > em_ret_near_imm+0x3a/0x580 arch/x86/kvm/emulate.c:3189 > x86_emulate_insn+0x1d87/0x5880 arch/x86/kvm/emulate.c:5292 > > CPU: 0 PID: 6232 Comm: syz-executor.3 Not tainted 6.8.0-rc4-syzkaller-00267-g0f1dd5e91e2b #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 > ===================================================== #syz fix: KVM: x86: Clean up partially uninitialized integer in emulate_pop()