From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-io1-f72.google.com (mail-io1-f72.google.com [209.85.166.72]) (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 3EA5F38397 for ; Mon, 1 Jul 2024 10:08:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.72 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719828537; cv=none; b=M7x9pNcTyC3cm86i7ppVsN9o6Yc/pjQBgqZXs3s0n9M6HNkRTKOwJvyqbYMXIDsr3cZUQfPcQX5n2xrn7vTPfbhnMeoulh/PdDDCW3i+UwQbtwU5sDeglGBHoUc8uC8Mi5X4ZrssqF4a82C+WxNj8ObsmNKlaEhvsgT+qpJRlMc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719828537; c=relaxed/simple; bh=DBE7iAf6douD2ekCMunjZ6GvuaMCKlqv3UvoSJdfo64=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=sEnya9qlk3Xq/CMmiAgbt/snV49qSvMl7IZ4QYtXXhB3P2yLBrfRHmZxB0mke3QGZNRgBiurbFUqUkpDe5YrnkmWEsJWyON6Gu/n0E0Sbg6C3Cppzze7bGlC1z5bEseYPb+k+f/9EmUk5rn8zhHXLaEYFI4GMZ09KKSmwmrs+G4= 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=209.85.166.72 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-f72.google.com with SMTP id ca18e2360f4ac-7f3c9b72aebso307290439f.3 for ; Mon, 01 Jul 2024 03:08:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1719828535; x=1720433335; 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=2P3DiKTRhPXgRbdLfmRBRDpp1MsjZKjZ8JgmQvxrVMU=; b=Q8KKFF4M1zdCaVR/L/g6iiuLp52ydNoTMoV+57txJl1DeQ2v9ZU3atoTG+DvlLmJid 0AMCV1uiuUQ2nJ4thO3fJPEt5FTKrGZIKacDqLt+Z1eOZoeizarvkfQKf9xONACIggK+ x7tZYwOYvOxeMk3ytHV5wYnEqre5ZuT70g5qqho7Z3DqZADGqPGmdQYhVP+zBAE2ech6 EmZnBEN2ypmPsO65vPUBe6CJVZ1BOW93q3B6Nz3fQKurbvXzrV4InQRIyaawKBWCciDa haDLGHp1ligC9F+9gz6fTFMR6thRvWcyCJIL/lA57qEevpzImgS5etWx30WoTxbN3A9z HQUQ== X-Gm-Message-State: AOJu0Yw83o2fKZ86veMAl54ewxt/aUgGtxTbz+xybEgou1CYwKGlTaFM DI2DkipvGeU9dGZNxSoa1IrEueLyMIbZIAZYexU/IP1DW1X3jkMlYyb8QiidA1cJBAw2R+M7dLG yY1bsi/nnRwc/LETGHWW4FsohsrDEIZ02Zfgx3Nq80uYtQ7ggce9xAIM= X-Google-Smtp-Source: AGHT+IEdfNicUut4M3jlEVimVVVhwNk8nA4O0ohYD8vGaqHdcXsx10hHJ5UtgfyNHyQUBxQBIS2EXZ4vimAv4rpf20W8IEfnGivj Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6602:6d8b:b0:7f6:28ed:efe5 with SMTP id ca18e2360f4ac-7f62ee8869bmr45896939f.2.1719828534415; Mon, 01 Jul 2024 03:08:54 -0700 (PDT) Date: Mon, 01 Jul 2024 03:08:54 -0700 In-Reply-To: <0000000000004cf0fe06160c8d71@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000de633e061c2cc882@google.com> Subject: Re: [syzbot] [syzbot] [bpf?] KMSAN: uninit-value in htab_percpu_map_lookup_elem From: syzbot To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" For archival purposes, forwarding an incoming command email to linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com. *** Subject: [syzbot] [bpf?] KMSAN: uninit-value in htab_percpu_map_lookup_elem Author: wojciech.gladysz@infogain.com #syz test: https://linux.googlesource.com/linux/kernel/git/torvalds/linux e478cf26c556e4ab572ab0ab2306c986901dcd61 --- kernel/bpf/verifier.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 36ef8e96787e..13a9c2e2908a 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7146,8 +7146,8 @@ static int check_stack_range_initialized( * reads. However, if raw_mode is not set, we'll do extra * checks below. */ - bounds_check_type = BPF_WRITE; - clobber = true; + clobber = !meta || meta->raw_mode; + bounds_check_type = clobber ? BPF_WRITE : BPF_READ; } else { bounds_check_type = BPF_READ; } @@ -7230,8 +7230,7 @@ static int check_stack_range_initialized( stype = &state->stack[spi].slot_type[slot % BPF_REG_SIZE]; if (*stype == STACK_MISC) goto mark; - if ((*stype == STACK_ZERO) || - (*stype == STACK_INVALID && env->allow_uninit_stack)) { + if (*stype == STACK_ZERO) { if (clobber) { /* helper can write anything into the stack */ *stype = STACK_MISC; @@ -8748,6 +8747,8 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, meta->map_uid = reg->map_uid; break; case ARG_PTR_TO_MAP_KEY: + /* always mark read access */ + meta->raw_mode = false; /* bpf_map_xxx(..., map_ptr, ..., key) call: * check that [key, key + map->key_size) are within * stack limits and initialized @@ -8763,7 +8764,7 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, } err = check_helper_mem_access(env, regno, meta->map_ptr->key_size, false, - NULL); + meta); break; case ARG_PTR_TO_MAP_VALUE: if (type_may_be_null(arg_type) && register_is_null(reg)) -- 2.35.3