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=1793209393; b=XE58c3NfGGvyURrowHYJWrGauZ0vyYZ7u2+yeDJkaPLoIl8ivYo0vRZwH2+Xr5jBdBo2 4nHGGFqqkna1EwWD4tQ1EKI3pUzIUswFOcT4cgSXzxHxKZCHD2aoqfYomHlNCzzuQfVGK a+7ylIYsMMG8S3gR28Hani4g2bTg0xbLWo3Ed58Tgsvebm74vFarGkQ6qIBogWH66sISj jlc5r50/zM0JEl5WV3wtYgVkveqqpjeRJNoZqBOMRLAIkJEFEvaiMD0ESN1qaunQoPmHr 0d9il6z8st0ps4BCQ4EdHNWoAsSZBbHCsZzN3SI8cbXNQFWyeor9ToVq+SnmrxmyvYQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793209393; 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=4LS5CnNU+KOqr+mwSdYwtjgxw+zBs/ZME3IERctpdwM=; b=FEWe+e/FaMABBGtCMSqK1z5ADXfZnFWI3BFVn+ycUUG3eT/zdksk5uefJ89ql37F59E6 rBnmCZGzwc9VmAgREPLRFGRYJl2tThOAgqe5eDsWNqs/Ok0rErQurthGm+Y5749AyZ4Ri KHw97XARzuZEJnaafjDPZjtSPPdhB5e6uBb8H1pcGHgZT3Rxn6NAxFyyBdZw209PqjKkE ZoQgb5Mlq0KyQ/RVgHeIpqMC6VIbM23lYopux/2K8T5Gv8iS1nncoHakSbZbfHtqVRF1b 0B3BBoFnNVr8392lPGGSEiF6/ZAIHwPYHqk1FlI94H8rjO8wN5BM37/96niPvnu5EDg== 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=YxB+JTM3; 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 BBFEE606A31C; Wed, 28 Oct 2026 17:43:12 +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=YxB+JTM3 Received: by smtp.kernel.org (Postfix) with ESMTPSA id CEC501F01825; Wed, 28 Oct 2026 17:43:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793209392; bh=4LS5CnNU+KOqr+mwSdYwtjgxw+zBs/ZME3IERctpdwM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=YxB+JTM3USSEFSgc1mw9pu8LJYk2AMQe02NkFaDGW3k+bKKG5rQQeONrhAwnqAf6M vYFdeyX3qQTP4pUVzGDbMXTqjzFlh5vM02hkk5EPxrFaWz4rHIigdjJ9ejmxoWETvL 3dEqtpGeSIlrm6m+eOo21zkJLILvkG/tVz8h5Ul4= 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 5.10 454/516] sctp: revalidate output stream after association connect wait Date: Wed, 28 Oct 2026 18:00:06 +0100 Message-ID: <20261028170014.235443145@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170003.522232767@linuxfoundation.org> References: <20261028170003.522232767@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 5.10-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 @@ -1785,6 +1785,18 @@ 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, @@ -1799,16 +1811,9 @@ 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; @@ -1832,10 +1837,9 @@ 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)) { @@ -1850,6 +1854,11 @@ 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; }