From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 CC3A13A1CED; Tue, 16 Dec 2025 12:31:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765888278; cv=none; b=bqCNlkZ1/rm17KS6kJQINx42nkVVHgYCQYdOtVCJ8aKi0OxDO8z2C+r/BjNXggts930zHA4bXDOdB9axPISB3Bxy7oWIp7e7NPvDXxFndyujBpluJxprcRZo4W2jEVQLxoOiGhqAkhi3TYDbPalNT8jwzt0uwb8lVZ+TMjwt8/U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765888278; c=relaxed/simple; bh=ydFGeRDlZCBLb5ngHgVCxz1BXN0TtT4c2J04xswMW9E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jYdDKCh4qYukTSeUNCiAXt2Kq16qu7WGj8L0GenoOpOi/U3ANx+DdAHC9jP4vMaIFenLXzuHMLlWG/g6MjR0OSzpW9EIdjBHZ+4GztT+g4cr7DZOBi+zBubo6r8rU4B3SU2o1wJe07TVtpO9cZvkXsr3nDu1x+sTxB3B7Z8GBEg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=WBqQ5y1w; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="WBqQ5y1w" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 17054C4CEF5; Tue, 16 Dec 2025 12:31:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1765888278; bh=ydFGeRDlZCBLb5ngHgVCxz1BXN0TtT4c2J04xswMW9E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WBqQ5y1wtR81+t1yEgyZeScglkfknhbJpv4h8wi8rYoh/VZH5CiU1RmYtf02/r09N jQ1x6xi7JeZ4VfZLJamzaquIJuD7a/Bhq5H469sgMSv6FpHN4D81odzqJCHI/4lz+z D0M4gk0ZuryDius0E1eVZP6rOmotOqiYZqrJs/6I= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Liang Li , Beniamino Galvani , Antoine Tenart , Ido Schimmel , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.18 485/614] net: vxlan: prevent NULL deref in vxlan_xmit_one Date: Tue, 16 Dec 2025 12:14:12 +0100 Message-ID: <20251216111418.943713812@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251216111401.280873349@linuxfoundation.org> References: <20251216111401.280873349@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Antoine Tenart [ Upstream commit 1f73a56f986005f0bc64ed23873930e2ee4f5911 ] Neither sock4 nor sock6 pointers are guaranteed to be non-NULL in vxlan_xmit_one, e.g. if the iface is brought down. This can lead to the following NULL dereference: BUG: kernel NULL pointer dereference, address: 0000000000000010 Oops: Oops: 0000 [#1] SMP NOPTI RIP: 0010:vxlan_xmit_one+0xbb3/0x1580 Call Trace: vxlan_xmit+0x429/0x610 dev_hard_start_xmit+0x55/0xa0 __dev_queue_xmit+0x6d0/0x7f0 ip_finish_output2+0x24b/0x590 ip_output+0x63/0x110 Mentioned commits changed the code path in vxlan_xmit_one and as a side effect the sock4/6 pointer validity checks in vxlan(6)_get_route were lost. Fix this by adding back checks. Since both commits being fixed were released in the same version (v6.7) and are strongly related, bundle the fixes in a single commit. Reported-by: Liang Li Fixes: 6f19b2c136d9 ("vxlan: use generic function for tunnel IPv4 route lookup") Fixes: 2aceb896ee18 ("vxlan: use generic function for tunnel IPv6 route lookup") Cc: Beniamino Galvani Signed-off-by: Antoine Tenart Reviewed-by: Ido Schimmel Tested-by: Ido Schimmel Link: https://patch.msgid.link/20251126102627.74223-1-atenart@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/vxlan/vxlan_core.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c index a5c55e7e4d795..e957aa12a8a44 100644 --- a/drivers/net/vxlan/vxlan_core.c +++ b/drivers/net/vxlan/vxlan_core.c @@ -2349,7 +2349,7 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, int addr_family; __u8 tos, ttl; int ifindex; - int err; + int err = 0; u32 flags = vxlan->cfg.flags; bool use_cache; bool udp_sum = false; @@ -2454,12 +2454,18 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, rcu_read_lock(); if (addr_family == AF_INET) { - struct vxlan_sock *sock4 = rcu_dereference(vxlan->vn4_sock); + struct vxlan_sock *sock4; u16 ipcb_flags = 0; struct rtable *rt; __be16 df = 0; __be32 saddr; + sock4 = rcu_dereference(vxlan->vn4_sock); + if (unlikely(!sock4)) { + reason = SKB_DROP_REASON_DEV_READY; + goto tx_error; + } + if (!ifindex) ifindex = sock4->sock->sk->sk_bound_dev_if; @@ -2534,10 +2540,16 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, ipcb_flags); #if IS_ENABLED(CONFIG_IPV6) } else { - struct vxlan_sock *sock6 = rcu_dereference(vxlan->vn6_sock); + struct vxlan_sock *sock6; struct in6_addr saddr; u16 ip6cb_flags = 0; + sock6 = rcu_dereference(vxlan->vn6_sock); + if (unlikely(!sock6)) { + reason = SKB_DROP_REASON_DEV_READY; + goto tx_error; + } + if (!ifindex) ifindex = sock6->sock->sk->sk_bound_dev_if; -- 2.51.0