From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail115-95.sinamail.sina.com.cn (mail115-95.sinamail.sina.com.cn [218.30.115.95]) (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 6588D1429E for ; Sun, 17 Mar 2024 10:07:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=218.30.115.95 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710670060; cv=none; b=d5tGuwhsC5ejxF2skEeGBIOw+reUcoJJo+jxeH5xb1loN+DAT1x2KQeE5TPcuOkxPtpUgnXUxlrWCozj59NhuTNYMmW8WzX6Tj33YZCaXfIRkX/o/uK6ckTQt9RuaMS8JfmGuNAJZuE3hmOQf4M2OoVhKf/Y27cSCwokL3LZEqo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710670060; c=relaxed/simple; bh=Dd+txECsWPxDo8/UX9xOHTYg/YqF/JMxmfWhmQhjSdk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=N6Jwt+OmRo+dFouI1wK4/MBNt9O2UNO/SpYT1TIGMn43lUsM+3DWfEYrM2FlabHozacIEzu7yPw/v7e6wPmk+3/75+lcKl6bGuQiIXerpnywNrktp1n2OOSoJ06v+OwqU+wFs4pYeEQQ1K/jnQ6oB1V0zEvLpvh92PplNyg24mM= 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=218.30.115.95 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)([116.24.9.14]) by sina.com (172.16.235.24) with ESMTP id 65F6C04B00001617; Sun, 17 Mar 2024 18:05:02 +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: 20741545089403 X-SMAIL-UIID: B3FC33FDA7A341D68DA4CFD9E69C11CF-20240317-180502-1 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: Sun, 17 Mar 2024 18:04:51 +0800 Message-Id: <20240317100451.2053-1-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://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git fe46a7dd189e --- 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 --- x/kernel/rcu/tree.c +++ y/kernel/rcu/tree.c @@ -4025,6 +4025,7 @@ static void rcu_barrier_entrain(struct r wake_nocb = was_alldone && rcu_segcblist_pend_cbs(&rdp->cblist); if (rcu_segcblist_entrain(&rdp->cblist, &rdp->barrier_head)) { atomic_inc(&rcu_state.barrier_cpu_count); + wake_nocb = true; } else { debug_rcu_head_unqueue(&rdp->barrier_head); rcu_barrier_trace(TPS("IRQNQ"), -1, rcu_state.barrier_sequence); --