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 603A713AA35 for ; Mon, 1 Jul 2024 10:19:45 +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=1719829186; cv=none; b=Gjrm/xoP5cX/sdfmR3MbOCHLzgQSa39HxB71QQUJxLTq2JVtm4VTXwtwvYzKtGnPuox2H7+Rb0O4xFjgX+nUzxxA94fTyC000AxExuN3IPkUvbyIgX3JWXHSMOfflNR+8HdxANaePIQ8m9bvziroj44TYVD5sHa5JjxPCG/Fk0g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719829186; c=relaxed/simple; bh=R8TFp0xEYuV7raeik2lyJR4VyRiUrnocL84SZk1BbBY=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=dpdRSbLrpgp/QjV5h5kSocE4I8A2ye1oIW66mDJW2cFXz+jKUqCn8TzR8kNLjTSgfYxomlrDnIGQawH235eORdwmQylp2gJQTWJwS3vbtdfKtwohfCXuH3aEWAmZcXr6y7JyAVSMlkQRks/lW3IvD9t7mgzilpmcqLvaCKRgJjg= 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-7f61da4d7beso328881739f.2 for ; Mon, 01 Jul 2024 03:19:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1719829184; x=1720433984; 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=WB3NrFq68/M3/4CXR5WTqwWcpKGtWEP1edv5y/Wzsx4=; b=Elpdpa11GP/66NVzanrMqqTcl4MBMhlrzWNcLH97AJCOwgA0f16zITv/3FKB/l52Kb 0wDXwvwdQG2K8+31/EuMOZF9yr7e2fogVup6+eBnpGt3iCKelY22sd/olS7scMqr6jjR Vux89JkvCALOgqRbw3vOZfA65W02YL2Tots4AE6dNDW69xHzqlPV3ltgmQC0aC8Glew/ o1XpG8zyOStT57JhaZZsVrRHldv16E2RQP+iQE7u8lBmFBOsyurEzgGNh1GK4YKDhdhe saTn4jueEeLtFgL7boSXIid/TYX0gtK2cfaSKuZaMiJ7m5glOGl3+0DBPv+cWZBl9X2h Oy1A== X-Gm-Message-State: AOJu0YztdFvtS0Pci6TXl9gHBo6W1Vl3vF9/j6VT/0/zxwRL7a9mHz4s vAQTbsfsVZv4gJ0FfA6mBno57Ddt0/WxMCsa+WdVgFDATOJgp1ktogynhN12v6z3hqcIA6q/oiN VZVC28NKLjxmSR8NpTyc8Xo1G5juKMKvtTg6eV379PdVDhlQL3TpXwyo= X-Google-Smtp-Source: AGHT+IHZAhcOQG9not90fVBt5p0X91NEAQZq54SNGfOu8HdL7jHRz2emuDVsHitDYdQJ5DLf9VVfXuvXP+1zUimKxufUJqPPnt9m Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6638:871d:b0:488:e34a:5f76 with SMTP id 8926c6da1cb9f-4bbb6bce7e5mr441528173.1.1719829184558; Mon, 01 Jul 2024 03:19:44 -0700 (PDT) Date: Mon, 01 Jul 2024 03:19:44 -0700 In-Reply-To: <00000000000067f65105edbd295d@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000009ecd1c061c2cef15@google.com> Subject: Re: [syzbot] [syzbot] KMSAN: uninit-value in bpf_prog_run_generic_xdp 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] KMSAN: uninit-value in bpf_prog_run_generic_xdp 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