From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-170.mta0.migadu.com (out-170.mta0.migadu.com [91.218.175.170]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3D4356A00B for ; Tue, 9 Apr 2024 05:35:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.170 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712640926; cv=none; b=mqOyfrgF1VnBEaSXxXf0LvboQmay6nEGdEShEUVZhBDlx1+LnNKme2pkqztBGI1OZ3Z3j9OxmkO+Kd/twxoNqDQDDgAbjanUqH1tplmu2wCFWuHbVdt3/WjFDspDmbWpVZVgQczn4afqZ1i/labYhxEB7fwV7oMCrlqkOdrDB1k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712640926; c=relaxed/simple; bh=XhHRctfVaCz2w502f+LjDY2L6sQ4gi2VmzK4Ei0Fet4=; h=Message-ID:Date:MIME-Version:Subject:To:References:From:Cc: In-Reply-To:Content-Type; b=t43IluVM3zBw4Gn9TpIYaMhaQeuihbSPAJgDSuqNGkmWMbuh7378de9nti+VfEg1FjmMKTFLDg3m4dTtAq6jJEBdiOydY5Qg4p/Hc7LovToAST9DgX3jU+DK16uwqiGnmixArMYpTJTU+zyG1TBSlb46UOswfyOyWfGupZr9s/0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=JYA5zrFI; arc=none smtp.client-ip=91.218.175.170 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="JYA5zrFI" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1712640922; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vf1j7wSZq2M24p6/dNYg1VPX+BthblGI9d+1+yhGlLs=; b=JYA5zrFIXZLzwBtix3jjPqkEJWf87TXyh6PC2Of0d4GEnhH0Yyblvm3Q+Yre7UacBl0R4k lh55o/ib/QDTNxCIbpK4Irhw18qt+1rlM2rJqG79ZjST5NIs6DKL30/B//uxnRxQKhUOQr GHwx5yKlLdXeKcRByeEIYxJpELpbHQA= Date: Mon, 8 Apr 2024 22:35:12 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [syzbot] [bpf?] KMSAN: uninit-value in bpf_bprintf_prepare To: syzbot References: <000000000000a1a6990611ea8b4d@google.com> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Martin KaFai Lau Cc: 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, sdf@google.com, song@kernel.org, syzkaller-bugs@googlegroups.com, yonghong.song@linux.dev In-Reply-To: <000000000000a1a6990611ea8b4d@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 2/21/24 12:55 PM, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: c1ca10ceffbb Merge tag 'scsi-fixes' of git://git.kernel.or.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=1364db0c180000 > kernel config: https://syzkaller.appspot.com/x/.config?x=e3dd779fba027968 > dashboard link: https://syzkaller.appspot.com/bug?extid=c2dc95f7d0825a145992 > 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/83d019f0ac47/disk-c1ca10ce.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/49e05dd7a23d/vmlinux-c1ca10ce.xz > kernel image: https://storage.googleapis.com/syzbot-assets/68ec9fa2d33d/bzImage-c1ca10ce.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+0x20d7/0x23b0 kernel/bpf/helpers.c:904 > bpf_bprintf_prepare+0x20d7/0x23b0 kernel/bpf/helpers.c:904 > ____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 #syz dup: [syzbot] [bpf?] [net?] KMSAN: uninit-value in dev_map_lookup_elem > 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: 6318 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-00331-gc1ca10ceffbb #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 > =====================================================