From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f202.google.com (mail-pf1-f202.google.com [209.85.210.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E89A67D3F4 for ; Wed, 21 Feb 2024 14:02:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708524143; cv=none; b=f1sTIiFMy/l82kLIx3r4gaIZrofcuwQ0vhHk39lEwnaOI8ApU4Vgx6FfTD73ykTV3KUw2/GCVsS5bJoj6SXVhvkRP8eAT6RQTkyeC3IFZKqhmULzbFjH2K486vBeonfIoFjwaPUkqD7oqfuxHeSHAQukKxnKvugBbX8OGh08UCM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708524143; c=relaxed/simple; bh=dTek2E7jXJK0EGI3Wlek8LmLnzUne7yFDDD7rfKMk9Y=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=gY+5iDjESbenB4batdbCJJexyMm/pTrzatuAX6xBBSBWU/NU9RTelzh312ktWteFAtXVlUqgzN8RHPvNJn6YJV4MwB+Jzag9yYkT/0qd7cvNK4PBNn5Vebe7Sv8570ZX1k9pm30SBPpzq0D3xpf/LISN7zQso48IaZnRD8zmmW8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Ij2N9qP2; arc=none smtp.client-ip=209.85.210.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Ij2N9qP2" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-6e3a5d1ca1eso2848407b3a.2 for ; Wed, 21 Feb 2024 06:02:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1708524141; x=1709128941; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=jFcAXLxuJ2hj6tXb8HK3JEiOXAeHYKmjz7J6WSMN/44=; b=Ij2N9qP2A2iGkxWp3/tW9QeiHVH0rqGDlPaw3ZUam21NEZHPm9K3kKq8S7YtGf289f 8kyIu/SwztpjUq+83T2P81qvJI/31dKbsFk38xpkgV61b/K6HrplKFmK0VHRJsQ21eJA FA/1TIhXPGFYvcQ0s2bS9yOoU3i/1VqpkTh4bKzJVsAsExsE7Cc9uFIbMi7yCTgvp1de 6bteDqQYgNkeV1GX+Sa6joFeOnnL237iGPsu9zdf4N7bV4SmGed8lKpNzDmCfxqNg1dr JPZBwKBHNuWyzbT2KZyoEvXfF1ejbDF9xi6JNyJjBCiVSuv+7niABez2rRqTtVW16QNb WT7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1708524141; x=1709128941; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=jFcAXLxuJ2hj6tXb8HK3JEiOXAeHYKmjz7J6WSMN/44=; b=DkLtn5lMj3G+jVhFoa8H71moXzaFRBJH3/r4VdWL7tnbzX3Hrb188EjQq3YFaWSyM9 y3tvG4AOEmaUe3xvPSLUenTAiJI9ot9Tsj+N9y4ZeZ1KjjYySJJzgh5PTkRR2NjNv2UU gv6z3RWg/q9OdZw3naYd9f8KD09596beb5dlejuxK/bKUJv0W4foIXs8+Zxvvocrydfu P4t5BrBmFKfhN4/eVaI/THy8tub8dZap7+8XjSiG6PAgueN93DCk5h6vmeXh6se78Hhf qcpm6fAHP2Cf1HzyVqOT90BD/yvVQm+wNZqhlIS/fdX03cJRMCgXFqd0DFAVecR+NS8z jxlw== X-Forwarded-Encrypted: i=1; AJvYcCX7DhUzkJ8NIQxTCi/ZsL8Qq0NOw6q2eyWDu9MLCRHFZFlNk22BvvoWlnBDrae6rwFwcFqWfDLVxwx5lfI1kEUeKvP0 X-Gm-Message-State: AOJu0YxEfFRKrEKXqJZjfPzg9gxyYchvBV5Oq00dcL9txrAMQdmfObOW ofmGTpSMAo/EOPbd7CUeYq0lEgSRV/BcTVYo9qbTnx2mcJD11h/C/NQuG2QwcijnHjPB2KVPRHl KyA== X-Google-Smtp-Source: AGHT+IGRBUSegRKWvY9k/MUiR2zPJpvxmSAVwmL409Aq1G+pJ/bRUUEiomtWWOZYvhWEyQpKPyyiJsTtiU0= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a05:6a00:2d2a:b0:6e4:8fd5:e415 with SMTP id fa42-20020a056a002d2a00b006e48fd5e415mr41118pfb.6.1708524141325; Wed, 21 Feb 2024 06:02:21 -0800 (PST) Date: Wed, 21 Feb 2024 06:02:19 -0800 In-Reply-To: <000000000000bc78610611e4bba1@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <000000000000bc78610611e4bba1@google.com> Message-ID: Subject: Re: [syzbot] [kvm?] KMSAN: uninit-value in em_ret 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 Wed, Feb 21, 2024, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: b401b621758e Linux 6.8-rc5 > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=15cd41c2180000 > kernel config: https://syzkaller.appspot.com/x/.config?x=1b015d567058472 > dashboard link: https://syzkaller.appspot.com/bug?extid=ee5eb98a07d2c1fb30df > 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/c32ff3cbe7ed/disk-b401b621.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/17621a870a21/vmlinux-b401b621.xz > kernel image: https://storage.googleapis.com/syzbot-assets/b06ad3ca55ee/bzImage-b401b621.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+ee5eb98a07d2c1fb30df@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+0x124/0x130 arch/x86/kvm/emulate.c:2238 > assign_eip_near arch/x86/kvm/emulate.c:829 [inline] > em_ret+0x124/0x130 arch/x86/kvm/emulate.c:2238 > x86_emulate_insn+0x1d87/0x5880 arch/x86/kvm/emulate.c:5292 > x86_emulate_instruction+0x13c9/0x30a0 arch/x86/kvm/x86.c:9171 > kvm_emulate_instruction arch/x86/kvm/x86.c:9251 [inline] > complete_emulated_io arch/x86/kvm/x86.c:11208 [inline] > complete_emulated_mmio+0x70b/0x8b0 arch/x86/kvm/x86.c:11268 > kvm_arch_vcpu_ioctl_run+0x1837/0xb890 arch/x86/kvm/x86.c:11380 > 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+0x37/0x130 arch/x86/kvm/emulate.c:2234 > x86_emulate_insn+0x1d87/0x5880 arch/x86/kvm/emulate.c:5292 > > CPU: 0 PID: 5793 Comm: syz-executor.0 Not tainted 6.8.0-rc5-syzkaller #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()