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 A473F423A7C; Tue, 31 Mar 2026 16:59:45 +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=1774976385; cv=none; b=idRTGE+Uh2lyRFO6mm3ygFfF9hUl7V9Qr4kqFS/I8bdXnjgOXyaLQ3NJrVthtfu5iAUbdRV/o9aZRcJWkrypya1ujAqgNDqUfE2PsIbi/CEt1CKu7RlvIWdvU/6C9sBroXA1ZstZLRl+2A27JX+olCXnjp4VzsAF9Mdf/l6HfRk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774976385; c=relaxed/simple; bh=06mkK/eFmBm/rxmkUbOBB1uEFUuU3zmI+iPRMNmoUEc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=C3k/ovQbibs2pUseBU621pdr+dHWCwwH+4RXtEgooZXAvj34MnwX8ULIHqZ3c6bIHheSFoE6nvtfjuAzjENS+loRoZX6faq9riQeGjoS+MGYWqJbL9Dv7Ro/p9/KM0t4yxDS6H4/9dD6ndH0EZc5LfjcQJoz/lC5DUjrh7qETQI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sBmBK8sM; 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="sBmBK8sM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3110BC19423; Tue, 31 Mar 2026 16:59:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1774976385; bh=06mkK/eFmBm/rxmkUbOBB1uEFUuU3zmI+iPRMNmoUEc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sBmBK8sM8DdpxZ96lmBkrndd0tKQ6PWhTHz2omrdR8WExj+xkSqx2/UuZdofSkWSr TZBLqdUahaW0MzKgoviWgQVaSp0qOyi+dt7EZq5nsIQ2ut7H1/98lZhY+PZd83D7UJ fFnRQNhf8a0uhEJOBiDYo63vBEMgSdkMG7KjI1JE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hao Long , Fernando Fernandez Mancera , Steffen Klassert , Sasha Levin Subject: [PATCH 6.18 073/309] xfrm: iptfs: fix skb_put() panic on non-linear skb during reassembly Date: Tue, 31 Mar 2026 18:19:36 +0200 Message-ID: <20260331161756.175655302@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260331161753.468533260@linuxfoundation.org> References: <20260331161753.468533260@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: Fernando Fernandez Mancera [ Upstream commit 0b352f83cabfefdaafa806d6471f0eca117dc7d5 ] In iptfs_reassem_cont(), IP-TFS attempts to append data to the new inner packet 'newskb' that is being reassembled. First a zero-copy approach is tried if it succeeds then newskb becomes non-linear. When a subsequent fragment in the same datagram does not meet the fast-path conditions, a memory copy is performed. It calls skb_put() to append the data and as newskb is non-linear it triggers SKB_LINEAR_ASSERT check. Oops: invalid opcode: 0000 [#1] SMP NOPTI [...] RIP: 0010:skb_put+0x3c/0x40 [...] Call Trace: iptfs_reassem_cont+0x1ab/0x5e0 [xfrm_iptfs] iptfs_input_ordered+0x2af/0x380 [xfrm_iptfs] iptfs_input+0x122/0x3e0 [xfrm_iptfs] xfrm_input+0x91e/0x1a50 xfrm4_esp_rcv+0x3a/0x110 ip_protocol_deliver_rcu+0x1d7/0x1f0 ip_local_deliver_finish+0xbe/0x1e0 __netif_receive_skb_core.constprop.0+0xb56/0x1120 __netif_receive_skb_list_core+0x133/0x2b0 netif_receive_skb_list_internal+0x1ff/0x3f0 napi_complete_done+0x81/0x220 virtnet_poll+0x9d6/0x116e [virtio_net] __napi_poll.constprop.0+0x2b/0x270 net_rx_action+0x162/0x360 handle_softirqs+0xdc/0x510 __irq_exit_rcu+0xe7/0x110 irq_exit_rcu+0xe/0x20 common_interrupt+0x85/0xa0 Fix this by checking if the skb is non-linear. If it is, linearize it by calling skb_linearize(). As the initial allocation of newskb originally reserved enough tailroom for the entire reassembled packet we do not need to check if we have enough tailroom or extend it. Fixes: 5f2b6a909574 ("xfrm: iptfs: add skb-fragment sharing code") Reported-by: Hao Long Closes: https://lore.kernel.org/netdev/DGRCO9SL0T5U.JTINSHJQ9KPK@imlonghao.com/ Signed-off-by: Fernando Fernandez Mancera Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin --- net/xfrm/xfrm_iptfs.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c index 3b6d7284fc70a..4e270628fc347 100644 --- a/net/xfrm/xfrm_iptfs.c +++ b/net/xfrm/xfrm_iptfs.c @@ -901,6 +901,12 @@ static u32 iptfs_reassem_cont(struct xfrm_iptfs_data *xtfs, u64 seq, iptfs_skb_can_add_frags(newskb, fragwalk, data, copylen)) { iptfs_skb_add_frags(newskb, fragwalk, data, copylen); } else { + if (skb_linearize(newskb)) { + XFRM_INC_STATS(xs_net(xtfs->x), + LINUX_MIB_XFRMINBUFFERERROR); + goto abandon; + } + /* copy fragment data into newskb */ if (skb_copy_seq_read(st, data, skb_put(newskb, copylen), copylen)) { -- 2.51.0