linux-kernel - [PATCH] ipc: create_ipc_ns: drop mqueue mount on sysctl setup failure

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20251021181341.670297-1-vlad_kulikov_c@pm.me>
Date: Tue, 21 Oct 2025 21:13:39 +0300
From: Vlad Kulikov <vlad.kulikov.c@...il.com>
To: Christian Brauner <brauner@...nel.org>,
	Jan Kara <jack@...e.cz>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Aleksa Sarai <cyphar@...har.com>,
	David Hildenbrand <david@...hat.com>,
	Simon Schuster <schuster.simon@...mens-energy.com>,
	Vlad Kulikov <vlad_kulikov_c@...me>,
	Ma Wupeng <mawupeng1@...wei.com>,
	linux-kernel@...r.kernel.org (open list)
Subject: [PATCH] ipc: create_ipc_ns: drop mqueue mount on sysctl setup failure

If setup_mq_sysctls(ns) fails after mq_init_ns(ns) succeeds, the error
path skipped releasing the internal kernel mqueue mount kept in
ns->mq_mnt. That leaves the vfsmount/superblock referenced until final
namespace teardown, i.e. a resource leak on this rare failure edge.

Unwind it by calling mntput(ns->mq_mnt) before dropping user_ns and
freeing the IPC namespace. This mirrors the normal ordering used in
free_ipc_ns().

Signed-off-by: Vlad Kulikov <vlad_kulikov_c@...me>
---
 ipc/namespace.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/ipc/namespace.c b/ipc/namespace.c
index 59b12fcb40bd..cf62d11a09b9 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -75,10 +75,10 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
 
 	err = -ENOMEM;
 	if (!setup_mq_sysctls(ns))
-		goto fail_put;
+		goto fail_mq_mount;
 
 	if (!setup_ipc_sysctls(ns))
-		goto fail_mq;
+		goto fail_mq_sysctls;
 
 	err = msg_init_ns(ns);
 	if (err)
@@ -92,9 +92,10 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
 
 fail_ipc:
 	retire_ipc_sysctls(ns);
-fail_mq:
+fail_mq_sysctls:
 	retire_mq_sysctls(ns);
-
+fail_mq_mount:
+	mntput(ns->mq_mnt);
 fail_put:
 	put_user_ns(ns->user_ns);
 	ns_common_free(ns);
-- 
2.32.0