From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out162-62-63-194.mail.qq.com (out162-62-63-194.mail.qq.com [162.62.63.194]) (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 10E6C12F585 for ; Tue, 9 Apr 2024 13:21:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=162.62.63.194 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712668908; cv=none; b=uiC7yXh56AuuVXhov8pKYyhYfNgO9I6Sz+0klrAotiXBqq/Oa1PjYVoAc8ToS8L43nvR3W9MM/N6LugWf7U7mb24nZVtrKOgtN/jq2DOs7O4J0HiTUJy0n6AxMSA7KLjgZ+JwjPKKTpyV96kEb/Cxelk8/LPPEnfI4gqSMGBNs0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712668908; c=relaxed/simple; bh=BIXtQbP9MP9nqx4vsOYb5xY/BLcCRo0aS7pkb/Oy9M4=; h=Message-ID:From:To:Cc:Subject:Date:In-Reply-To:References: MIME-Version; b=nUt0QxcBvvyyOhdC+/uxKcBaRoCR4QalFmyB4EC5NnQj3C5AZB4VFqeyDH5afgM3OtsCzjuii4hNSiH49oJA9sQTkmiSExadZLYXiooopgdLFUfiXp40IwbHw9hO0zAtfZuLsd7IUIoPA5ekYmZ1Kb96RNCkjW5RbdJ8RlRaBWM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com; spf=pass smtp.mailfrom=qq.com; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b=bRNsxKJO; arc=none smtp.client-ip=162.62.63.194 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=qq.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b="bRNsxKJO" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qq.com; s=s201512; t=1712668895; bh=YUtGez/XnDNg5xUU7tPR+7JYoTfIuuLZrutUQBX7E4w=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bRNsxKJOljO5gDXhx6JeJ7EgfIrKkNy1wlrEml8OwkdMFWtKpUXIyHPf5Xt56FLdu Yh4CdBaXsOEmotMF9CW5zrSWv8agAviPGaa7gi8R8/Qza3a6u3R2HSizC51hGOEwpv hVVa71o44xjd1eH5nofJx0bOjWh8EuWIZ/xJgr4k= Received: from pek-lxu-l1.wrs.com ([111.198.228.153]) by newxmesmtplogicsvrszb9-1.qq.com (NewEsmtp) with SMTP id 356A180B; Tue, 09 Apr 2024 21:13:22 +0800 X-QQ-mid: xmsmtpt1712668402t5chgs1d7 Message-ID: X-QQ-XMAILINFO: OXHA96V41vMDBwhYwn7+OjcGgzli3xXJ2XDxO3wfyTlv9jhUGCma8gVWdIuDuN q8gbpT2OeHrZgo4KnPTxPoOXTrr+jLmUXj0dn/aqJHpzPeqeMTjHBAuN0Ppaas2adCVyxYG8CzzP aShYl/WjyuH6yN1aND/6KraaC/HtUP6aeTos6AFQLq8581MSBKOMLifVxFwoo0dY5wb9+3wNgRZR mWMTEqAHfhLji65ddxmzut9n3WMYXg6xtwqo2EhKBTJirEEM7gWwnufhWF+rqn1El5waws8qzkD3 v2iK2Uqx+7gDtlujVJsnZxgHj9CR2QIGXagyWTqYrQOab6SikTD0YFAqmRqGZIbggb8tdEA3XVYt sEM38BH5O0DeCrmU2e/XAZi3TXVDp1DSopwHTFDH6453LvFAPr1yxp1+Hb8iVNflHkldj1TIGKWk JBE/tFj+itxDdiMcNZdGAJyfW24sif6QqDgu9hhhUcULarS641sNTtVkNHaLrhS4P0QqG7JM+Dl0 1A7110ENLuwaAXUlw3v5kKQlOqyWSrLHVMxgNQBv37PiItIccuQOi3WlnpJgJG4sHge6V53Dv14Q oRMWgwZzeBHOs4T90fZkUumAEvwqvXDhJGmtQ3vylWnYIc5q3q6/TS7DIQ+U1ouG0UjLLk2Yda+D Ep1HJMpcBzjIrC11nLztBM1QPf3Ulj0x9Nymjk3UxP9iAkaDKQVYe1fpCSafoCQE62+oUJ1LkAyw gqCMrpHc3xP3aPnFaYcOept/8i+vSNNpkbhG4z2eLam1B74/1EVRkRG/B29iKOfo2sTw/K/7iGTV 4+iHzcS8Cw7OTRiUIbJQ83l54qY+i+UsnOW4zCetBiHCXeP+tq3wY4zkFHrScqMpgM1jNG6HkcSd rNT7gzJQcJDXWp0Zg4Ozbfls9tpNK2l2UVodLKdc2dDNZzLZXUQRU3edWQE2YB91oofgXma5d7oJ fGCC6//qsNs39ZvJXBNUPWLsza0clge7u8p3J1b85BJQ5wD5bN5astSCfIYgB5RJR39hNQaEgYF2 i2EQItu4zNgv6BoCSO X-QQ-XMRINFO: M/715EihBoGSf6IYSX1iLFg= From: Edward Adam Davis To: syzbot+9b8be5e35747291236c8@syzkaller.appspotmail.com Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [bpf?] KMSAN: uninit-value in strnchr Date: Tue, 9 Apr 2024 21:13:23 +0800 X-OQ-MSGID: <20240409131322.4166944-2-eadavis@qq.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <0000000000009e2ff406130de279@google.com> References: <0000000000009e2ff406130de279@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit please test uini in strnchr #syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 04b8076df253 diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 449b9a5d3fe3..54abc67c48c7 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -826,7 +826,8 @@ int bpf_bprintf_prepare(char *fmt, u32 fmt_size, const u64 *raw_args, u64 cur_arg; char fmt_ptype, cur_ip[16], ip_spec[] = "%pXX"; - fmt_end = strnchr(fmt, fmt_size, 0); + kmsan_unpoison_memory(fmt, fmt_size); + fmt_end = strnchrnul(fmt, fmt_size, 0); if (!fmt_end) return -EINVAL; fmt_size = fmt_end - fmt; -- 2.43.0