From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-io1-f70.google.com (mail-io1-f70.google.com [209.85.166.70]) (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 7B6B91854 for ; Sun, 3 Mar 2024 06:48:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709448506; cv=none; b=l2QGZpF6Kzl9DY18bSPb77xsMVbwBzCHtirQayQ0W1PduYM3neANYNltPaz1c1KOOdq+GMOE6k9GTJQCBVGf9qJD17HwOyftbAnhNX8REuF5J/NCnJrDTDJRIfE9cBWeCSXZQyRhWN0tgSNoooHA8yUos6bcQOvX8V6vU3CvvAE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709448506; c=relaxed/simple; bh=/RkFaEv69N54+n+alVnD9ZvnuO4IILRdNsLvW0GRjzc=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=nea16HcHMMmFsfhcKjDCJXBo+bUkTQWrhLRfJccs4y0gxu6FHw2wHMCDMHb5FU/wK1C1B3u3gyL36fTG26pJCkxshu12QqcG4IMbbL1ETzhYe1GD2/dN1VTKcbpJgMy4oyXOsvqKa8QJuAudXmkcQphSlaxzAgDibkU3g+i/v+Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.166.70 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-io1-f70.google.com with SMTP id ca18e2360f4ac-7c7f57fa5eeso323203239f.1 for ; Sat, 02 Mar 2024 22:48:24 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709448503; x=1710053303; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=oRY+Um+nXIGBLfrwGmjSxp5HdHzDmIRFT9dg5t6FNxM=; b=a28Y49VebXB3KR00vMZg4iH7bG1rcjeASDHwef4YDS7WCsBvyWZw6vvGPR3hP9hZ7K N8erwTASLya2aYbp8SXCadNv4Eo8xICZH3FWZrsGQjgpOLFDp0bgK+iVesXGUreGYQ87 F05gyMaVV1ToTMZfW0TyblGs10QcLhhlPUWWFTmECri9zD9X5THFHG11zCQKOnZ/UaNj 2RLLvK3IKHeyCiJiuCV3f9GCjk0Dd8Kjrhq1WjNvXM64IkOEoJQzXmsmhi1iW+DVGCSa Pu1cFg61eYjbne0Ekf/8Oz8ksYn0Pf8LlEwptbd3pG236n2kg1jdUNTYqsERrecGM905 1nzA== X-Forwarded-Encrypted: i=1; AJvYcCUbR7YR8QkEQpqa39ddwXG+fJqFzYvxFN5DFgiRsTyyTQqou0L3u3fXw7r5wNNn/xixgAgrf9+36ty+IREQEy4i5u5Z+rvB4WgUKyG9 X-Gm-Message-State: AOJu0YyVK8E1FK36ntmP86QxHsnetpOkfImdUCFpSLNlg+7l8JvJUpdF jwwniT29RAsDGArX5BuhJ6cZBclpqgbL/e7CEQu+JAsZbdAo3VWKLcvtKZ5duDg6ZCfx8ZPM5+h 6Q+nnI9igij+6B9X8w9pGF5vG4aQGzdWdbPgDMWmAaJuxAR1ytvUI/jw= X-Google-Smtp-Source: AGHT+IE1heZQPqpGkYgIJVnl4gI9nkm/6x7o0digqOKV0BpZ6VtEwn+t6V3vbw7pMW9K1zA98fikUSotPAiW2peux02dXSCvZjJ/ Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6638:408b:b0:474:eb37:5718 with SMTP id m11-20020a056638408b00b00474eb375718mr4757jam.0.1709448503711; Sat, 02 Mar 2024 22:48:23 -0800 (PST) Date: Sat, 02 Mar 2024 22:48:23 -0800 In-Reply-To: <000000000000a1a6990611ea8b4d@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000d3640a0612bbfe22@google.com> Subject: Re: [syzbot] [bpf?] KMSAN: uninit-value in bpf_bprintf_prepare From: syzbot To: andrii@kernel.org, ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, haoluo@google.com, john.fastabend@gmail.com, jolsa@kernel.org, kpsingh@kernel.org, linux-kernel@vger.kernel.org, martin.lau@linux.dev, sdf@google.com, song@kernel.org, syzkaller-bugs@googlegroups.com, xrivendell7@gmail.com, yonghong.song@linux.dev Content-Type: text/plain; charset="UTF-8" syzbot has found a reproducer for the following issue on: HEAD commit: 04b8076df253 Merge tag 'firewire-fixes-6.8-rc7' of git://g.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=117de082180000 kernel config: https://syzkaller.appspot.com/x/.config?x=80c7a82a572c0de3 dashboard link: https://syzkaller.appspot.com/bug?extid=c2dc95f7d0825a145992 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15289dca180000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16bc0bba180000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/a4610b1ff2a7/disk-04b8076d.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/991e9d902d39/vmlinux-04b8076d.xz kernel image: https://storage.googleapis.com/syzbot-assets/a5b8e8e98121/bzImage-04b8076d.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+c2dc95f7d0825a145992@syzkaller.appspotmail.com ===================================================== BUG: KMSAN: uninit-value in bpf_bprintf_prepare+0x1ec4/0x23b0 kernel/bpf/helpers.c:934 bpf_bprintf_prepare+0x1ec4/0x23b0 kernel/bpf/helpers.c:934 ____bpf_snprintf kernel/bpf/helpers.c:1060 [inline] bpf_snprintf+0x141/0x360 kernel/bpf/helpers.c:1044 ___bpf_prog_run+0x2180/0xdb80 kernel/bpf/core.c:1986 __bpf_prog_run288+0xb5/0xe0 kernel/bpf/core.c:2226 bpf_dispatcher_nop_func include/linux/bpf.h:1231 [inline] __bpf_prog_run include/linux/filter.h:651 [inline] bpf_prog_run include/linux/filter.h:658 [inline] bpf_prog_run_pin_on_cpu include/linux/filter.h:675 [inline] bpf_flow_dissect+0x127/0x470 net/core/flow_dissector.c:991 bpf_prog_test_run_flow_dissector+0x6f4/0xa20 net/bpf/test_run.c:1359 bpf_prog_test_run+0x6af/0xac0 kernel/bpf/syscall.c:4107 __sys_bpf+0x649/0xd60 kernel/bpf/syscall.c:5475 __do_sys_bpf kernel/bpf/syscall.c:5561 [inline] __se_sys_bpf kernel/bpf/syscall.c:5559 [inline] __x64_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5559 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 stack created at: __bpf_prog_run288+0x45/0xe0 kernel/bpf/core.c:2226 bpf_dispatcher_nop_func include/linux/bpf.h:1231 [inline] __bpf_prog_run include/linux/filter.h:651 [inline] bpf_prog_run include/linux/filter.h:658 [inline] bpf_prog_run_pin_on_cpu include/linux/filter.h:675 [inline] bpf_flow_dissect+0x127/0x470 net/core/flow_dissector.c:991 CPU: 0 PID: 5018 Comm: syz-executor377 Not tainted 6.8.0-rc6-syzkaller-00250-g04b8076df253 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 ===================================================== --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.