From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail115-24.sinamail.sina.com.cn (mail115-24.sinamail.sina.com.cn [218.30.115.24]) (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 5DF8A1DA58 for ; Sat, 9 Mar 2024 08:45:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=218.30.115.24 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709973954; cv=none; b=uRG8Tzn+3c1HlSN5Anr3E5m0D26GwGrZcehZ1v6QGPguf5OnndAoHmXtmlik0tps1z4n1jCtDWNjZ9QtEITPPQtm2ZmnpUcNXtOwYH61uyp0N+DO1H37QEBv+GO1D3nxjsSubua0V0Kfda2CLsqKZQngxn6yRrq2uBH2pjHhD9A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709973954; c=relaxed/simple; bh=z0vziq730r0rbGxpWWfEs2MxuHCDeJDqpQf7hapyd3M=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=rGZfIxU1bAodXoQM+PPg0jOoAWpU3Dw6q8hBVq8iybiX45PFMTfT9bXf9BSbIkHAAHSfUQYnuCKkybgDd6KJ+xAQhLdZM9wtcd3kaJJrd+DMFvNPF1m31oUBR5f/K6lrP/HGzkDBOGzfXJnPr7O7xJzBKjkY/8E/dhZlgcBoLJo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; arc=none smtp.client-ip=218.30.115.24 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([113.88.49.120]) by sina.com (10.75.12.45) with ESMTP id 65EC21B100000E77; Sat, 9 Mar 2024 16:45:42 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 78475331457290 X-SMAIL-UIID: 1E7A401DEEEE444C935E6B9CC412C67D-20240309-164542-1 From: Hillf Danton To: syzbot Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [netfilter?] KASAN: slab-use-after-free Read in ip_skb_dst_mtu Date: Sat, 9 Mar 2024 16:45:27 +0800 Message-Id: <20240309084527.1943-1-hdanton@sina.com> In-Reply-To: <0000000000008b9c410612fbd266@google.com> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Wed, 06 Mar 2024 02:57:18 -0800 > syzbot found the following issue on: > > HEAD commit: 805d849d7c3c Merge tag 'acpi-6.8-rc7' of git://git.kernel... > git tree: upstream > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1025fa6a180000 #syz test https://github.com/fbq/linux.git rcu-exp.2024.01.29b --- x/drivers/net/ipvlan/ipvlan_core.c +++ y/drivers/net/ipvlan/ipvlan_core.c @@ -426,6 +426,7 @@ static noinline_for_stack int ipvlan_pro .daddr = ip4h->daddr, .saddr = ip4h->saddr, }; + struct sock *sk; rt = ip_route_output_flow(net, &fl4, NULL); if (IS_ERR(rt)) @@ -439,7 +440,12 @@ static noinline_for_stack int ipvlan_pro memset(IPCB(skb), 0, sizeof(*IPCB(skb))); + sk = skb->sk; + if (!sk) + goto err; + refcount_inc(&sk->sk_wmem_alloc); err = ip_local_out(net, skb->sk, skb); + sk_free(sk); if (unlikely(net_xmit_eval(err))) DEV_STATS_INC(dev, tx_errors); else --