From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f177.google.com (mail-pl1-f177.google.com [209.85.214.177]) (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 5B93A369D57 for ; Thu, 30 Jul 2026 09:05:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785402346; cv=none; b=TLopMqwViMkSIEM5x84UJu/VuoV9PBV/o+j7p3U4SZtPm1uzyXvfnv/QKMie+29iZD0rvs7n70/LlHl9vb4OL+2827y8n/eM/bZicjc4nkuVL1cAj6dvJQ0tQjTaZWL0kFWtcrxZwtizxFNbcwNvHFMv7i5QAstVpEBC4CGr1q8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785402346; c=relaxed/simple; bh=kL3IVIOe1ALgbrOXk8HHOMTEE77ThONwsjZG93CgMo4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=mArb89kI1svMXx0GvbHKCJic8I/Itbi0pHYS+B4qyPZo4wI81OzJ1CpBtsNkZYdr5SKS0Kvv2Rqo7LMaqj+N/MMVBaRkmWzbyB+sUcPvxNiJxSOzAMokpKlp0z6+Xs3gN6vDwXMnss8ad2Zsq7qWMLiJRloGFo4bndnauU+MoIo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=nBvVYFHF; arc=none smtp.client-ip=209.85.214.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="nBvVYFHF" Received: by mail-pl1-f177.google.com with SMTP id d9443c01a7336-2ceb096e675so23872585ad.0 for ; Thu, 30 Jul 2026 02:05:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1785402345; x=1786007145; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=CpKlGxNrk83Ii+YIm4YNlRDoPzJNOT0xfV5KNDUW93I=; b=nBvVYFHFbjYQTnCofCA9ks75kdDzRumkvCh9rWUEPgwpuconZFERRu1m1cA320yIvs 4LMgNPTkaY4QT4d6kYcEGyRV0eNXeElR21szhtVlBZK8pwk0izYer/+LDf+lAShJK30+ ReR8Oc0rIE/9mdSKJTGg0c8WX6SpugumR3679LhELayb4FIph6sRciGQCPLLpvrpd97/ bUAe0S2nG1MYsMM910VUZ/YUB3p7nm0ZfljtCVm/KGlu6B7u5wpa8rSdDr+G79pnpAPh OXKyuUj51Q5DxVbdKqrZA24NWVzgTnCjb56hqM3B6PflIl3X/KzBiTEs0rGSP9bJmuoQ x7mQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785402345; x=1786007145; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=CpKlGxNrk83Ii+YIm4YNlRDoPzJNOT0xfV5KNDUW93I=; b=bg83Qtd+5S7CW/LPGi1RyYqKRacnVQpCWqrbFsBlsHMPU5X1lDlecAH7nPY1demHgj jqIKuZrZNsYx9iVY0rPcrugOJbju6c/UAH8rXq6Pxx+JsGEedjMSK86WB0E+7Ji/dTA+ WzDnGIqiNv3KB49RsZjQ4DbKg8t2U8KveJ3FeCcU2S/zsxL8T1nzPSPSHxyJYB5Qckcs qTHbi2+O8f677fpVZOcmgW+uC6Eo/X4ybjw8aQDb9nYUz0IAEgR8BBgEQu5gL+KCV0jb qvhKh92BDNd6duZJRXEDxMwqqGLoW3NpPDTPrhWeKSDR5WmYJNOqwhPAo2mx1fpVl8tS oZbg== X-Forwarded-Encrypted: i=1; AHgh+RrIJPC7M2pDtjmAW++m8vmbwlGQWr3xfDZIKt6Pk3AB9JS+QA8zmUypkdWiswCoDmIPz/lCR9FD/auv@vger.kernel.org X-Gm-Message-State: AOJu0YyFCSzR2h5L+uKhivTxh5jyUH2nUZI/LXZtgWkGYQJnVhZdUcvK beuSxTItlcZOotQlD6J/crJ+uopQUth37H9cVYbYQCtxTO6+lexOGuak X-Gm-Gg: AR+sD12wZv1MIUKcoe97tTcvBDU6i9vTGxHKSbJuLLIzzF4OIpmVtlX9PM+fMbcte64 FtUo6eN7Hh0P2vle1FtymIk9YHCypBlR3TpkXHuVs077zmedS9kNVIwesG5eOIJYCLc5qCYxY8s acflBcgRYW0lp8HXi5ytWci8Kk4a6csZnl+3JFHPhpfxRmtTibXE54F86fdY/I+uApYdKWqRGmJ MMukja9T4V3e0yapjy4pS9wu9zK199UE+TrY4RKonxXEosu3+TnToPz0fZIhMNNEYUsNcpn9R9q pxxSOzFEVHtYb1Ca+TiTObCPxNAf5LouslD4WbRmVQRHePkyKX4iI5kj6Bz+GLyl62xw97XhpS5 RgzE1rIUMP+tySdOZFd/r66UsYCUDEqAyDjij807b4tQBW9lTOmOX3Eni9zHbMYbuHMoBAdQSiG uPKA/H2vq47MkK11pwHvoY1G8zgk05VttTpMR2tafU4NXhCShgeEMsVvQjdVxAye2fHfV7VgpGS rLcqnCDav2tzN46VVATSXeRxzt4P8pD3uAY X-Received: by 2002:a17:902:d983:b0:2cc:a977:4260 with SMTP id d9443c01a7336-2d035bdf26amr19397505ad.21.1785402344493; Thu, 30 Jul 2026 02:05:44 -0700 (PDT) Received: from JUNVYYANG-MC1.tencent.com ([43.132.141.24]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2d0228417adsm23387555ad.0.2026.07.30.02.05.41 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Thu, 30 Jul 2026 02:05:44 -0700 (PDT) From: Jun Yang To: netdev@vger.kernel.org Cc: Jun Yang , stable@kernel.org, TencentOS Corvus AI , Marcelo Ricardo Leitner , Xin Long , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , linux-sctp@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net] sctp: re-point retained control chunks on association migration Date: Thu, 30 Jul 2026 17:05:25 +0800 Message-ID: <20260730090537.27629-1-juny24602@gmail.com> X-Mailer: git-send-email 2.50.1 Precedence: bulk X-Mailing-List: linux-sctp@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Jun Yang sctp_control_set_owner_w() records the owning socket in a control chunk's skb->sk as a bare pointer. sctp_sock_migrate() re-owns the association's DATA chunks via sctp_for_each_tx_datachunk(), but that walk keys off chunk->msg and so skips control chunks: any control chunk the association still holds (for example the saved stream-reset request asoc->strreset_chunk, the ASCONF request/ack lists, or asoc->addip_last_asconf) keeps pointing at the old socket after the association is moved to the new one. Once the old socket is freed, a later retransmit reaches sctp_packet_transmit() -> skb_set_owner_w(head, chunk->skb->sk) and operates on the freed socket -- refcount_add() on its sk_wmem_alloc, then sk->sk_write_space() from sock_wfree() -- a use-after-free of struct sock. Re-point every control chunk the association still holds at the new socket right after sctp_assoc_migrate(), as is already done for DATA chunks. Control chunks carry no socket wmem charge and their skb destructor does not use skb->sk, so a bare owner update is sufficient. Fixes: d04adf1b3551 ("sctp: reset owner sk for data chunks on out queues when migrating a sock") Cc: stable@kernel.org Reported-by: TencentOS Corvus AI Signed-off-by: Jun Yang --- net/sctp/socket.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index c7b9e325ec1c..9a6da4e0d741 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -9522,6 +9522,30 @@ static void sctp_skb_set_owner_r_frag(struct sk_buff *skb, struct sock *sk) sctp_skb_set_owner_r(skb, sk); } +/* Control chunks record their owning socket in skb->sk as a bare pointer and + * are not reached by sctp_for_each_tx_datachunk(); re-point the ones the + * association still holds so migration does not leave them on the old socket. + */ +static void sctp_ctrl_set_owner_w(struct sctp_chunk *chunk, struct sock *sk) +{ + if (chunk && chunk->skb) + chunk->skb->sk = sk; +} + +static void sctp_for_each_tx_ctrlchunk(struct sctp_association *assoc, struct sock *sk) +{ + struct sctp_chunk *chunk; + + list_for_each_entry(chunk, &assoc->outqueue.control_chunk_list, list) + sctp_ctrl_set_owner_w(chunk, sk); + list_for_each_entry(chunk, &assoc->asconf_ack_list, transmitted_list) + sctp_ctrl_set_owner_w(chunk, sk); + list_for_each_entry(chunk, &assoc->addip_chunk_list, list) + sctp_ctrl_set_owner_w(chunk, sk); + sctp_ctrl_set_owner_w(assoc->strreset_chunk, sk); + sctp_ctrl_set_owner_w(assoc->addip_last_asconf, sk); +} + /* Populate the fields of the newsk from the oldsk and migrate the assoc * and its messages to the newsk. */ @@ -9633,6 +9657,7 @@ static int sctp_sock_migrate(struct sock *oldsk, struct sock *newsk, sctp_for_each_tx_datachunk(assoc, true, sctp_clear_owner_w); sctp_assoc_migrate(assoc, newsk); sctp_for_each_tx_datachunk(assoc, false, sctp_set_owner_w); + sctp_for_each_tx_ctrlchunk(assoc, newsk); /* If the association on the newsk is already closed before accept() * is called, set RCV_SHUTDOWN flag. -- 2.55.0