From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 6C0A7473C9F; Fri, 7 Aug 2026 15:27:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786116476; cv=none; b=lPLgpdDyll84lUmUVkQ+Pfv6RHBQ84Bv/EB9hF4gJWZnT78x8pI2N9JIE48CSWL0xgetJ+4PROvV3a5xWTzoYGnFQXoUIvKXgseNUjvGxuCwmIu4aod9yIFUTFIVIH7TFIeXwhm8GEfdvXEGwsbguT093bS7MkYWD8arvUhVYPI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786116476; c=relaxed/simple; bh=nx5MUrf2atMmDFgoTFNBD+ZBUGF3Uu5CY+unAWyW8mY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ekBorDHaPIsR/9mkfOF7vjSWwlujchqdUJQ9hZHJ0Tp83cMA1++IeWLMsDvdybe6gHUM8awq8rLLp97dbK6Ha28+3QN1T9Alx2BfG6HnoO4QeWmuV5M6h3xy2reJzOWkDkY/9FTNEGeNh7vJDL4jSz3zm3ZPVb/HxCljCO5OtRs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dYq4t6wM; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="dYq4t6wM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CED911F000E9; Fri, 7 Aug 2026 15:27:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786116475; bh=IT0J7vRfQvgVjw4tbI0g+a76nX18ipC1CMF7YzX3Pgw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=dYq4t6wM4nrDhO0n65Q010vxfLWKEm58/JEjx82F8RJWx/y1ZXdGjchaKFNciRwyW wzK0df372OmErMLeFih9isM+vsllnpQxd27Tjc5pxHOHbyVsvjGKkDmcajwvTTqoP5 eQSk80qoTvtBmooWOwx/SdPMBENKkd+J9wypf+wI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yuan Tan , Yifan Wu , Juefei Pu , Xin Liu , Qi Tang , Zhiling Zou , Ren Wei , Xin Long , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6 243/261] sctp: avoid auth_enable sysctl UAF during netns teardown Date: Fri, 7 Aug 2026 16:40:00 +0200 Message-ID: <20260807143420.652634793@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260807143415.358597922@linuxfoundation.org> References: <20260807143415.358597922@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zhiling Zou [ Upstream commit f8d5e7846025f4ab15a461235f8ebae9094a361a ] proc_sctp_do_auth() updates the SCTP control socket after changing net.sctp.auth_enable. The handler gets the per-net SCTP state from ctl->data, so an already opened sysctl file can still target a network namespace while that namespace is being torn down. SCTP previously registered its per-net sysctls from sctp_defaults_init(), while the control socket is created later from sctp_ctrlsock_init(). This exposed a window during initialization where auth_enable was writable before net->sctp.ctl_sock existed, and a teardown window where auth_enable stayed writable after inet_ctl_sock_destroy() had released the control socket. Move the per-net SCTP sysctl registration into sctp_ctrlsock_init() after sctp_ctl_sock_init() succeeds, and unregister the sysctl table before destroying the control socket in sctp_ctrlsock_exit(). If sysctl registration fails after the control socket was created, destroy the control socket in the same init path. Make sctp_sysctl_net_unregister() tolerate a missing header and clear the saved pointer so init-error and exit paths can safely share the unregister helper. Fixes: 15649fd5415e ("sctp: sysctl: auth_enable: avoid using current->nsproxy") Cc: stable@vger.kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Co-developed-by: Qi Tang Signed-off-by: Qi Tang Signed-off-by: Zhiling Zou Signed-off-by: Ren Wei Acked-by: Xin Long Link: https://patch.msgid.link/390cd5e91ed60eea27b0b64d0468301a9e73b808.1784033357.git.roxy520tt@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/sctp/protocol.c | 20 ++++++++++++-------- net/sctp/sysctl.c | 9 +++++++-- 2 files changed, 19 insertions(+), 10 deletions(-) --- a/net/sctp/protocol.c +++ b/net/sctp/protocol.c @@ -1394,10 +1394,6 @@ static int __net_init sctp_defaults_init net->sctp.l3mdev_accept = 1; #endif - status = sctp_sysctl_net_register(net); - if (status) - goto err_sysctl_register; - /* Allocate and initialise sctp mibs. */ status = init_sctp_mibs(net); if (status) @@ -1431,8 +1427,6 @@ err_init_proc: cleanup_sctp_mibs(net); #endif err_init_mibs: - sctp_sysctl_net_unregister(net); -err_sysctl_register: return status; } @@ -1447,7 +1441,6 @@ static void __net_exit sctp_defaults_exi net->sctp.proc_net_sctp = NULL; #endif cleanup_sctp_mibs(net); - sctp_sysctl_net_unregister(net); } static struct pernet_operations sctp_defaults_ops = { @@ -1461,16 +1454,27 @@ static int __net_init sctp_ctrlsock_init /* Initialize the control inode/socket for handling OOTB packets. */ status = sctp_ctl_sock_init(net); - if (status) + if (status) { pr_err("Failed to initialize the SCTP control sock\n"); + return status; + } + + status = sctp_sysctl_net_register(net); + if (status) { + inet_ctl_sock_destroy(net->sctp.ctl_sock); + net->sctp.ctl_sock = NULL; + } return status; } static void __net_exit sctp_ctrlsock_exit(struct net *net) { + sctp_sysctl_net_unregister(net); + /* Free the control endpoint. */ inet_ctl_sock_destroy(net->sctp.ctl_sock); + net->sctp.ctl_sock = NULL; } static struct pernet_operations sctp_ctrlsock_ops = { --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -630,11 +630,16 @@ int sctp_sysctl_net_register(struct net void sctp_sysctl_net_unregister(struct net *net) { + struct ctl_table_header *header = net->sctp.sysctl_header; const struct ctl_table *table; - table = net->sctp.sysctl_header->ctl_table_arg; - unregister_net_sysctl_table(net->sctp.sysctl_header); + if (!header) + return; + + table = header->ctl_table_arg; + unregister_net_sysctl_table(header); kfree(table); + net->sctp.sysctl_header = NULL; } static struct ctl_table_header *sctp_sysctl_header;