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 EE5D77F7F5; Wed, 7 Aug 2024 15:13:05 +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=1723043586; cv=none; b=KwmlMt7SBxVQhbPETvxPsKzCMypp26/ULTWJhhjueQdvO+yZTSQZH4fMarXB5wXWqmHqgzxfCDO75q5eURvGfHsnSBgHwqRdop+L3xt9GhsgLkB/dgv28rljBaLZxK/ArjUaqTO/7JDc9k4qzcW1kklhqbS/p52Vz3SknC1KkT8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723043586; c=relaxed/simple; bh=UGxlVpYWLhWxNkVPmcYuagv/U7x23ZE/qTxLHRklWLc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mKXlw9gcqfNAERnF32uKkH5iSEQ/sTbfH7V+x5r7PJqQTnQ1+3AjCtRwFlhjzsQYPdFhwFODeMXMOk4LogKCSACKayFbkONR4YH8D5qH0lblZ3NlXEtxGDx36eM05shV9v+QSYtsKRqT2pBPDsopATtafcTDEMyhJzX2127ZfsE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=DItz94cT; 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="DItz94cT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4D493C32781; Wed, 7 Aug 2024 15:13:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1723043585; bh=UGxlVpYWLhWxNkVPmcYuagv/U7x23ZE/qTxLHRklWLc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DItz94cTpOPGslWLfkTBSOMB+JU80N4ZSmRyRIJxhpLHhOU+suybsDAZS2FjZ5XoD k0Wte7yam64EDCuSHymMDJGLhEG5BpluCF1/deGLOWHccDfGVuxNW7citYJ3J0ilyP ySqjvaafcERjw2pHiLfNDCMR2BM+fsV8A6n5os7U= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alexey Gladkov , "Eric W. Biederman" , Christian Brauner , Davidlohr Bueso , Joel Granados , Kees Cook , Luis Chamberlain , Manfred Spraul , Andrew Morton , Sasha Levin Subject: [PATCH 6.1 05/86] sysctl: allow to change limits for posix messages queues Date: Wed, 7 Aug 2024 16:59:44 +0200 Message-ID: <20240807150039.428878191@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240807150039.247123516@linuxfoundation.org> References: <20240807150039.247123516@linuxfoundation.org> User-Agent: quilt/0.67 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 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexey Gladkov [ Upstream commit f9436a5d0497f759330d07e1189565edd4456be8 ] All parameters of posix messages queues (queues_max/msg_max/msgsize_max) end up being limited by RLIMIT_MSGQUEUE. The code in mqueue_get_inode is where that limiting happens. The RLIMIT_MSGQUEUE is bound to the user namespace and is counted hierarchically. We can allow root in the user namespace to modify the posix messages queues parameters. Link: https://lkml.kernel.org/r/6ad67f23d1459a4f4339f74aa73bac0ecf3995e1.1705333426.git.legion@kernel.org Signed-off-by: Alexey Gladkov Signed-off-by: Eric W. Biederman Link: https://lkml.kernel.org/r/7eb21211c8622e91d226e63416b1b93c079f60ee.1663756794.git.legion@kernel.org Cc: Christian Brauner Cc: Davidlohr Bueso Cc: Joel Granados Cc: Kees Cook Cc: Luis Chamberlain Cc: Manfred Spraul Signed-off-by: Andrew Morton Stable-dep-of: 98ca62ba9e2b ("sysctl: always initialize i_uid/i_gid") Signed-off-by: Sasha Levin --- ipc/mq_sysctl.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c index fbf6a8b93a265..ce03930aced55 100644 --- a/ipc/mq_sysctl.c +++ b/ipc/mq_sysctl.c @@ -12,6 +12,7 @@ #include #include #include +#include static int msg_max_limit_min = MIN_MSGMAX; static int msg_max_limit_max = HARD_MSGMAX; @@ -76,8 +77,43 @@ static int set_is_seen(struct ctl_table_set *set) return ¤t->nsproxy->ipc_ns->mq_set == set; } +static void mq_set_ownership(struct ctl_table_header *head, + struct ctl_table *table, + kuid_t *uid, kgid_t *gid) +{ + struct ipc_namespace *ns = + container_of(head->set, struct ipc_namespace, mq_set); + + kuid_t ns_root_uid = make_kuid(ns->user_ns, 0); + kgid_t ns_root_gid = make_kgid(ns->user_ns, 0); + + *uid = uid_valid(ns_root_uid) ? ns_root_uid : GLOBAL_ROOT_UID; + *gid = gid_valid(ns_root_gid) ? ns_root_gid : GLOBAL_ROOT_GID; +} + +static int mq_permissions(struct ctl_table_header *head, struct ctl_table *table) +{ + int mode = table->mode; + kuid_t ns_root_uid; + kgid_t ns_root_gid; + + mq_set_ownership(head, table, &ns_root_uid, &ns_root_gid); + + if (uid_eq(current_euid(), ns_root_uid)) + mode >>= 6; + + else if (in_egroup_p(ns_root_gid)) + mode >>= 3; + + mode &= 7; + + return (mode << 6) | (mode << 3) | mode; +} + static struct ctl_table_root set_root = { .lookup = set_lookup, + .permissions = mq_permissions, + .set_ownership = mq_set_ownership, }; bool setup_mq_sysctls(struct ipc_namespace *ns) -- 2.43.0