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 E89901F7064; Tue, 21 Jan 2025 18:07:17 +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=1737482838; cv=none; b=TjQZj9t7CxQsFaWGOLsTznVL5F3sBb527UoFFtih8JqaGQeBforBLMJyu4Zxgy5batK1SZt9zx3O6x65zG5opTSYt4Mxl6yVu3s6NIfPBZ+eA3S0x6p7iWWJMTBSAfWpdvOmKy10HY7XpkeOwDT1VeCe16FFa3+ZBc80GC6U2nw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737482838; c=relaxed/simple; bh=68PTr0uGuNFS/zI+xkBWcdH7EdiXDHElxKebOq+h6oI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OxWgixxwiELiTdHHgrqXEtns3Bof5W1yN16p7JtIUEgexbS6T40Q5c+MVXG0C/k0w17cAhAjnV7+gJgHx/ZAbeH4IAUPBDixAJljQyzEG2itYLf1ggmqIeopCeJMruS7JKyzmcbWS/KjyYGl6h4J3T1+VwPF+GUf5GZXyl/SHrs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nII64vCR; 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="nII64vCR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66B46C4CEE3; Tue, 21 Jan 2025 18:07:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1737482837; bh=68PTr0uGuNFS/zI+xkBWcdH7EdiXDHElxKebOq+h6oI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nII64vCRfKmdTHdfCMB+r08Ai4Ppfcg7FahEX+hLQnDUmpKmjsraAmOqjWYRwrXB8 cU14ZnJ10vfMFpyM3AfoIgmnbyXp94DGzb6+KL7NDTGw+fQcz3Hn25YHO7MNBIJCFL 5AcgHQtReX08jtzJyRe+G8DBO6pQKLVJINyI3h/g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Al Viro , "Matthieu Baerts (NGI0)" , Jakub Kicinski Subject: [PATCH 5.15 025/127] sctp: sysctl: rto_min/max: avoid using current->nsproxy Date: Tue, 21 Jan 2025 18:51:37 +0100 Message-ID: <20250121174530.642442349@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250121174529.674452028@linuxfoundation.org> References: <20250121174529.674452028@linuxfoundation.org> User-Agent: quilt/0.68 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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Matthieu Baerts (NGI0) commit 9fc17b76fc70763780aa78b38fcf4742384044a5 upstream. As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using container_of(). Note that table->data could also be used directly, as this is the only member needed from the 'net' structure, but that would increase the size of this fix, to use '*data' everywhere 'net->sctp.rto_min/max' is used. Fixes: 4f3fdf3bc59c ("sctp: add check rto_min and rto_max in sysctl") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/67769ecb.050a0220.3a8527.003f.GAE@google.com [1] Suggested-by: Al Viro Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250108-net-sysctl-current-nsproxy-v1-5-5df34b2083e8@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/sctp/sysctl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -426,7 +426,7 @@ static int proc_sctp_do_hmac_alg(struct static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write, void *buffer, size_t *lenp, loff_t *ppos) { - struct net *net = current->nsproxy->net_ns; + struct net *net = container_of(ctl->data, struct net, sctp.rto_min); unsigned int min = *(unsigned int *) ctl->extra1; unsigned int max = *(unsigned int *) ctl->extra2; struct ctl_table tbl; @@ -454,7 +454,7 @@ static int proc_sctp_do_rto_min(struct c static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write, void *buffer, size_t *lenp, loff_t *ppos) { - struct net *net = current->nsproxy->net_ns; + struct net *net = container_of(ctl->data, struct net, sctp.rto_max); unsigned int min = *(unsigned int *) ctl->extra1; unsigned int max = *(unsigned int *) ctl->extra2; struct ctl_table tbl;