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 81F24248BA1; Wed, 15 Jan 2025 10:50:47 +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=1736938247; cv=none; b=vFhKhV8XiYgDuunPd+Qbr5IuCoDm7c5/qAwTxAMOTWGByR6AG+aHOdV6Xb9ZN18GrD9LBQh4puGKFDDiYsQxDlJJATaQg1kS1LV7Q11olzrv1kVL4v9zNYpVEjajbms+dkDyFWadd2ndVuB386/6wL9YXLw0q5xA9K0p5spbW6g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736938247; c=relaxed/simple; bh=6nuX7+VQVs3hl8HxA2WkoHtWIYpdsb3v9yj8L5qg1pE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rfWFsuSl/CCOz/Mf/QxpJOGnr6nAwbl0c1h8ANBKVmShdvWDM7OEaA2G7QAXBn8WUYPZUATWNd+YYbuZSxX6ZqaBAnXCiPE7TUvT1YZehvcfn0mBGCYoZjsE9SCeGkfK8DE4N2JFj2O+xuXrYC6ljNrx3Eo8cC5P1MLevYLKpTA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=O00lvOm2; 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="O00lvOm2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4C4AC4CEDF; Wed, 15 Jan 2025 10:50:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1736938247; bh=6nuX7+VQVs3hl8HxA2WkoHtWIYpdsb3v9yj8L5qg1pE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=O00lvOm2/wqbQM9v6hhiuSuZe3lzWMnXJ23tQloXiwTjs2JlmAJNF5QtwJp4laxr8 QWBtdeATJERcp6uuXiZcjJo0CIsr5POQi3lgZ4usn502ex0xz05ZMOs5BF9S+JI2Qt EH824sfCXaXvwqVLlzwA+MPDVECgjveOxIn09bU8= 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 6.12 096/189] sctp: sysctl: rto_min/max: avoid using current->nsproxy Date: Wed, 15 Jan 2025 11:36:32 +0100 Message-ID: <20250115103610.153124630@linuxfoundation.org> X-Mailer: git-send-email 2.48.0 In-Reply-To: <20250115103606.357764746@linuxfoundation.org> References: <20250115103606.357764746@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 6.12-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 @@ -433,7 +433,7 @@ static int proc_sctp_do_hmac_alg(const s static int proc_sctp_do_rto_min(const 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; @@ -461,7 +461,7 @@ static int proc_sctp_do_rto_min(const st static int proc_sctp_do_rto_max(const 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;