From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-44.mimecast.com (us-smtp-delivery-44.mimecast.com [207.211.30.44]) (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 BEDA13C02 for ; Wed, 22 Jun 2022 20:14:10 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-510-tiqLrDOmP0egyC1vcjU4OA-1; Wed, 22 Jun 2022 16:07:35 -0400 X-MC-Unique: tiqLrDOmP0egyC1vcjU4OA-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8E6AF89C7DB; Wed, 22 Jun 2022 20:07:34 +0000 (UTC) Received: from comp-core-i7-2640m-0182e6.redhat.com (unknown [10.40.208.41]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0B4B4492CA5; Wed, 22 Jun 2022 20:07:32 +0000 (UTC) From: Alexey Gladkov To: LKML , Linux Containers , Dmitry Vyukov , "Eric W. Biederman" , Catalin Marinas , syzkaller-bugs@googlegroups.com, syzbot+b4b0d1b35442afbf6fd2@syzkaller.appspotmail.com Subject: [PATCH] ipc: Free mq_sysctls if ipc namespace creation failed Date: Wed, 22 Jun 2022 22:07:29 +0200 Message-Id: <20220622200729.2639663-1-legion@kernel.org> In-Reply-To: <8735fyhyvy.fsf@email.froward.int.ebiederm.org> References: <8735fyhyvy.fsf@email.froward.int.ebiederm.org> Precedence: bulk X-Mailing-List: containers@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.85 on 10.11.54.9 The problem that Dmitry Vyukov pointed out is that if setup_ipc_sysctls fails, mq_sysctls must be freed before return. executing program BUG: memory leak unreferenced object 0xffff888112fc9200 (size 512): comm "syz-executor237", pid 3648, jiffies 4294970469 (age 12.270s) hex dump (first 32 bytes): ef d3 60 85 ff ff ff ff 0c 9b d2 12 81 88 ff ff ..`............. 04 00 00 00 a4 01 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] kmemdup+0x23/0x50 mm/util.c:129 [] kmemdup include/linux/fortify-string.h:456 [inline] [] setup_mq_sysctls+0x4b/0x1c0 ipc/mq_sysctl.c:89 [] create_ipc_ns ipc/namespace.c:63 [inline] [] copy_ipcs+0x292/0x390 ipc/namespace.c:91 [] create_new_namespaces+0xdc/0x4f0 kernel/nsproxy.c:90 [] unshare_nsproxy_namespaces+0x9b/0x120 kernel/nsproxy.c:226 [] ksys_unshare+0x2fe/0x600 kernel/fork.c:3165 [] __do_sys_unshare kernel/fork.c:3236 [inline] [] __se_sys_unshare kernel/fork.c:3234 [inline] [] __x64_sys_unshare+0x12/0x20 kernel/fork.c:3234 [] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [] entry_SYSCALL_64_after_hwframe+0x46/0xb0 BUG: memory leak unreferenced object 0xffff888112fd5f00 (size 256): comm "syz-executor237", pid 3648, jiffies 4294970469 (age 12.270s) hex dump (first 32 bytes): 00 92 fc 12 81 88 ff ff 00 00 00 00 01 00 00 00 ................ 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] kmalloc include/linux/slab.h:605 [inline] [] kzalloc include/linux/slab.h:733 [inline] [] __register_sysctl_table+0x7b/0x7f0 fs/proc/proc_sysctl.c:1344 [] setup_mq_sysctls+0x12a/0x1c0 ipc/mq_sysctl.c:112 [] create_ipc_ns ipc/namespace.c:63 [inline] [] copy_ipcs+0x292/0x390 ipc/namespace.c:91 [] create_new_namespaces+0xdc/0x4f0 kernel/nsproxy.c:90 [] unshare_nsproxy_namespaces+0x9b/0x120 kernel/nsproxy.c:226 [] ksys_unshare+0x2fe/0x600 kernel/fork.c:3165 [] __do_sys_unshare kernel/fork.c:3236 [inline] [] __se_sys_unshare kernel/fork.c:3234 [inline] [] __x64_sys_unshare+0x12/0x20 kernel/fork.c:3234 [] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [] entry_SYSCALL_64_after_hwframe+0x46/0xb0 BUG: memory leak unreferenced object 0xffff888112fbba00 (size 256): comm "syz-executor237", pid 3648, jiffies 4294970469 (age 12.270s) hex dump (first 32 bytes): 78 ba fb 12 81 88 ff ff 00 00 00 00 01 00 00 00 x............... 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] kmalloc include/linux/slab.h:605 [inline] [] kzalloc include/linux/slab.h:733 [inline] [] new_dir fs/proc/proc_sysctl.c:978 [inline] [] get_subdir fs/proc/proc_sysctl.c:1022 [inline] [] __register_sysctl_table+0x5a9/0x7f0 fs/proc/proc_sysctl.c:1373 [] setup_mq_sysctls+0x12a/0x1c0 ipc/mq_sysctl.c:112 [] create_ipc_ns ipc/namespace.c:63 [inline] [] copy_ipcs+0x292/0x390 ipc/namespace.c:91 [] create_new_namespaces+0xdc/0x4f0 kernel/nsproxy.c:90 [] unshare_nsproxy_namespaces+0x9b/0x120 kernel/nsproxy.c:226 [] ksys_unshare+0x2fe/0x600 kernel/fork.c:3165 [] __do_sys_unshare kernel/fork.c:3236 [inline] [] __se_sys_unshare kernel/fork.c:3234 [inline] [] __x64_sys_unshare+0x12/0x20 kernel/fork.c:3234 [] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [] entry_SYSCALL_64_after_hwframe+0x46/0xb0 BUG: memory leak unreferenced object 0xffff888112fbb900 (size 256): comm "syz-executor237", pid 3648, jiffies 4294970469 (age 12.270s) hex dump (first 32 bytes): 78 b9 fb 12 81 88 ff ff 00 00 00 00 01 00 00 00 x............... 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] kmalloc include/linux/slab.h:605 [inline] [] kzalloc include/linux/slab.h:733 [inline] [] new_dir fs/proc/proc_sysctl.c:978 [inline] [] get_subdir fs/proc/proc_sysctl.c:1022 [inline] [] __register_sysctl_table+0x5a9/0x7f0 fs/proc/proc_sysctl.c:1373 [] setup_mq_sysctls+0x12a/0x1c0 ipc/mq_sysctl.c:112 [] create_ipc_ns ipc/namespace.c:63 [inline] [] copy_ipcs+0x292/0x390 ipc/namespace.c:91 [] create_new_namespaces+0xdc/0x4f0 kernel/nsproxy.c:90 [] unshare_nsproxy_namespaces+0x9b/0x120 kernel/nsproxy.c:226 [] ksys_unshare+0x2fe/0x600 kernel/fork.c:3165 [] __do_sys_unshare kernel/fork.c:3236 [inline] [] __se_sys_unshare kernel/fork.c:3234 [inline] [] __x64_sys_unshare+0x12/0x20 kernel/fork.c:3234 [] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [] entry_SYSCALL_64_after_hwframe+0x46/0xb0 Reported-by: syzbot+b4b0d1b35442afbf6fd2@syzkaller.appspotmail.com Signed-off-by: Alexey Gladkov --- ipc/namespace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/ipc/namespace.c b/ipc/namespace.c index 754f3237194a..e1fcaedba4fa 100644 --- a/ipc/namespace.c +++ b/ipc/namespace.c @@ -64,7 +64,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns, goto fail_put; if (!setup_ipc_sysctls(ns)) - goto fail_put; + goto fail_mq; sem_init_ns(ns); msg_init_ns(ns); @@ -72,6 +72,9 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns, return ns; +fail_mq: + retire_mq_sysctls(ns); + fail_put: put_user_ns(ns->user_ns); ns_free_inum(&ns->ns); -- 2.33.3