From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793207608; b=TDbxV64hJeD3SeRLDyt5ZkAraQ0hAJiO92+QDOmhVlR+9OeDGRwRf6LyncBk77SWjCLE 2BuOZts8ruI2dwtHNZJbNmHdSerbwwpeIcoP38p8HRX2CY9OX5XoBybQDgDtkXxtMPFoz hGFim1bBE/d+3iqOLLhLF3i5c2k4QjccuD+kffnpUcIIlolWPjKRR8O5eoSetqJl5UtJ5 TOQKg0tOMZN12anODumpxNVmW9o/CMP9M4d+rsvRYC9ARgKLOrfFN7sWeipxqYvBPu/OF iiTT3gs3hd+jyobohTDp9nVqOFgv5jARZI/m+N53EuvIcDv3+V0ZMvRyyYwjOmtipSg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793207608; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=YoICpxg4LeCY/dP8uE/awvKo2BcYpFXSPRbK8N/26RI=; b=eqhZxcCHYSeqzqPr2pHJKeo2kA1CXAFsBve0aCEsDXrt5i4kXuowLKEF3VJ4Roai83P0 DIIq+4wkHRpS7Dk5xTenD0VEVoFw8mcToM5k4Q9mSzoj2E3E5cTpooqAHC1uUyJUceTyf RCVp0pzc+NPULVOzW3sAwk/XbmoqAA1KDBFAyOjy4t7rAcdeYyxV7/507bkZnQ+dUsBTK bNHrBBqeEm1qepYDq9/KJc2GAounTeFxgZRHOhhPf8whdFtVfv+u/VvZzrrv3xwb4h8O6 QDXIAP/jJVYys8hQ0t2/IL8bQG5GDXuUl5XCo8i7TaNSSq1+AjqDqloNycYEp5acsIA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=XmQxagbE; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 658C6606A329; Wed, 28 Oct 2026 17:13:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=XmQxagbE Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6B4AF1F01828; Wed, 28 Oct 2026 17:13:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793207608; bh=YoICpxg4LeCY/dP8uE/awvKo2BcYpFXSPRbK8N/26RI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=XmQxagbECTwqdAGr8nMfDMitysxIRQAC+ttB2jP9isL9eN3lhVuHtxPfS/f+E4hVv yf9fu2TcBI3GXxsKXEtsRH6RzzrTwFfTaafDXPIYb8H2fCdAvBOprmm3w8AcO6xnbr Lydo5It3MEk2gMiEjhf4YBzgJeDocp8dSQUuKXB0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Daehyeon Ko <4ncienth@gmail.com>, Xin Long , Paolo Abeni Subject: [PATCH 6.12 074/247] sctp: revalidate output stream after association connect wait Date: Wed, 28 Oct 2026 17:57:57 +0100 Message-ID: <20261028165949.146189326@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028165947.349197979@linuxfoundation.org> References: <20261028165947.349197979@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daehyeon Ko <4ncienth@gmail.com> commit b7ad72414c673ce1fa1f463e807cd4f34f8be9bf upstream. When message interleaving is enabled, the first send waits for association establishment before building its data chunks. The wait drops the socket lock, and handshake processing can reduce the output stream count to the peer-advertised inbound stream count. sctp_stream_init() then frees the extension of every removed stream. The sender resumes with the stream that it checked before the wait. If the peer removed that stream, sctp_outq_tail() later dereferences its NULL extension. Fatal-oops policies then panic the host. KASAN: null-ptr-deref in range [0x38-0x3f] RIP: sctp_outq_tail+0x49e/0xaa0 Call Trace: sctp_primitive_SEND sctp_sendmsg_to_asoc sctp_sendmsg A range check alone is insufficient. Stream reconfiguration can grow the output count again while the lock is released without recreating extensions freed by the earlier shrink. The stream can then be in range while its extension remains NULL. The send-buffer wait has the same issue. Factor the range and extension checks into a helper and repeat both after each send-path wait that drops the socket lock. Once the lock is reacquired, the validation remains stable through data creation and queueing. If validation fails after the connect wait, the auto-created association is already established. Return ESRCH so the existing caller path keeps it under state-machine ownership instead of freeing it directly, which would leave protocol, counter and socket state inconsistent. Fixes: 668c9beb9020 ("sctp: implement assign_number for sctp_stream_interleave") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Daehyeon Ko <4ncienth@gmail.com> Acked-by: Xin Long Link: https://patch.msgid.link/20261007035739.3472432-1-4ncienth@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman --- net/sctp/socket.c | 33 +++++++++++++++++++++------------ 1 file changed, 21 insertions(+), 12 deletions(-) --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -1786,6 +1786,18 @@ static int sctp_sendmsg_check_sflags(str return 1; } +static int sctp_sendmsg_check_stream(struct sctp_association *asoc, + struct sctp_sndrcvinfo *sinfo) +{ + if (unlikely(sinfo->sinfo_stream >= asoc->stream.outcnt)) + return -EINVAL; + + if (unlikely(!SCTP_SO(&asoc->stream, sinfo->sinfo_stream)->ext)) + return sctp_stream_init_ext(&asoc->stream, sinfo->sinfo_stream); + + return 0; +} + static int sctp_sendmsg_to_asoc(struct sctp_association *asoc, struct msghdr *msg, size_t msg_len, struct sctp_transport *transport, @@ -1800,16 +1812,9 @@ static int sctp_sendmsg_to_asoc(struct s long timeo; int err; - if (sinfo->sinfo_stream >= asoc->stream.outcnt) { - err = -EINVAL; + err = sctp_sendmsg_check_stream(asoc, sinfo); + if (err) goto err; - } - - if (unlikely(!SCTP_SO(&asoc->stream, sinfo->sinfo_stream)->ext)) { - err = sctp_stream_init_ext(&asoc->stream, sinfo->sinfo_stream); - if (err) - goto err; - } if (sp->disable_fragments && msg_len > asoc->frag_point) { err = -EMSGSIZE; @@ -1830,10 +1835,9 @@ static int sctp_sendmsg_to_asoc(struct s err = sctp_wait_for_sndbuf(asoc, transport, &timeo, msg_len); if (err) goto err; - if (unlikely(sinfo->sinfo_stream >= asoc->stream.outcnt)) { - err = -EINVAL; + err = sctp_sendmsg_check_stream(asoc, sinfo); + if (err) goto err; - } } if (sctp_state(asoc, CLOSED)) { @@ -1848,6 +1852,11 @@ static int sctp_sendmsg_to_asoc(struct s err = -ESRCH; goto err; } + err = sctp_sendmsg_check_stream(asoc, sinfo); + if (err) { + err = -ESRCH; + goto err; + } } else { wait_connect = true; }