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 8A09A1F540C; Tue, 21 Jan 2025 18:07:15 +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=1737482837; cv=none; b=CsBTrukxCKwo6Vk96tz8a4Jyd/IfSt8jW2/383zs1JIZI+9gB9XH5R4mNpAyoCi3dz8QZczuR4hLRPEmX2TBf+nNnD7S18cU9nTjTe+etsCEbTxu80AamlvzDie9PmWUWv+JeWY8gwJjBqeKJgLv5ZDZhzCmvNMHDHAl+Sb8fl4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737482837; c=relaxed/simple; bh=2nQUHW9ATwQxlY4gl9GqosFLqec8ISuPVFNmBk4da+0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OETjXeElTUAoxfhE9FlT8DoycrLCOneKwE5dzXcvhf9BOquYubUnj0EYoO9ADYXa9sDnrF+3/3i2/mMAKQVoYAnytW0JMR9FimqbOB325ni3Lf2/5KupvDRTltaIr8pAvXy71N76biYDVvw+4emO1imwiquwjEVJomdDH7onti8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=i1ImT2n9; 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="i1ImT2n9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90AE4C4CEDF; Tue, 21 Jan 2025 18:07:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1737482835; bh=2nQUHW9ATwQxlY4gl9GqosFLqec8ISuPVFNmBk4da+0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=i1ImT2n92gvme+jHrwUAqwmq4U26LFOFaztvVWQf9Qop/bseA8MphijrEnJrb0wX8 F2KaE49SPWezoCbER7be5TtFCS/jnweiqaD59EDaSydbBY7nrMfbcnXSecTaccofrD 66Fsc/9LA4nZ0q8DhPzhcsr/UHYk23m4a9uHGq6U= 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 5.15 024/127] sctp: sysctl: cookie_hmac_alg: avoid using current->nsproxy Date: Tue, 21 Jan 2025 18:51:36 +0100 Message-ID: <20250121174530.605953925@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 ea62dd1383913b5999f3d16ae99d411f41b528d4 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.sctp_hmac_alg' is used. Fixes: 3c68198e7511 ("sctp: Make hmac algorithm selection for cookie generation dynamic") 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-v1-4-5df34b2083e8@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/sctp/sysctl.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -380,7 +380,8 @@ static struct ctl_table sctp_net_table[] static int proc_sctp_do_hmac_alg(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.sctp_hmac_alg); struct ctl_table tbl; bool changed = false; char *none = "none";