The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From db7cfc380900bc4243b09623fd72fabe0a8ff23b Mon Sep 17 00:00:00 2001 From: Alexey Gladkov legion@kernel.org Date: Wed, 22 Jun 2022 22:07:29 +0200 Subject: [PATCH] ipc: Free mq_sysctls if ipc namespace creation failed

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: [<ffffffff814b6eb3>] kmemdup+0x23/0x50 mm/util.c:129 [<ffffffff82219a9b>] kmemdup include/linux/fortify-string.h:456 [inline] [<ffffffff82219a9b>] setup_mq_sysctls+0x4b/0x1c0 ipc/mq_sysctl.c:89 [<ffffffff822197f2>] create_ipc_ns ipc/namespace.c:63 [inline] [<ffffffff822197f2>] copy_ipcs+0x292/0x390 ipc/namespace.c:91 [<ffffffff8127de7c>] create_new_namespaces+0xdc/0x4f0 kernel/nsproxy.c:90 [<ffffffff8127e89b>] unshare_nsproxy_namespaces+0x9b/0x120 kernel/nsproxy.c:226 [<ffffffff8123f92e>] ksys_unshare+0x2fe/0x600 kernel/fork.c:3165 [<ffffffff8123fc42>] __do_sys_unshare kernel/fork.c:3236 [inline] [<ffffffff8123fc42>] __se_sys_unshare kernel/fork.c:3234 [inline] [<ffffffff8123fc42>] __x64_sys_unshare+0x12/0x20 kernel/fork.c:3234 [<ffffffff845aab45>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff845aab45>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [<ffffffff8460006a>] 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: [<ffffffff816fea1b>] kmalloc include/linux/slab.h:605 [inline] [<ffffffff816fea1b>] kzalloc include/linux/slab.h:733 [inline] [<ffffffff816fea1b>] __register_sysctl_table+0x7b/0x7f0 fs/proc/proc_sysctl.c:1344 [<ffffffff82219b7a>] setup_mq_sysctls+0x12a/0x1c0 ipc/mq_sysctl.c:112 [<ffffffff822197f2>] create_ipc_ns ipc/namespace.c:63 [inline] [<ffffffff822197f2>] copy_ipcs+0x292/0x390 ipc/namespace.c:91 [<ffffffff8127de7c>] create_new_namespaces+0xdc/0x4f0 kernel/nsproxy.c:90 [<ffffffff8127e89b>] unshare_nsproxy_namespaces+0x9b/0x120 kernel/nsproxy.c:226 [<ffffffff8123f92e>] ksys_unshare+0x2fe/0x600 kernel/fork.c:3165 [<ffffffff8123fc42>] __do_sys_unshare kernel/fork.c:3236 [inline] [<ffffffff8123fc42>] __se_sys_unshare kernel/fork.c:3234 [inline] [<ffffffff8123fc42>] __x64_sys_unshare+0x12/0x20 kernel/fork.c:3234 [<ffffffff845aab45>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff845aab45>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [<ffffffff8460006a>] 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: [<ffffffff816fef49>] kmalloc include/linux/slab.h:605 [inline] [<ffffffff816fef49>] kzalloc include/linux/slab.h:733 [inline] [<ffffffff816fef49>] new_dir fs/proc/proc_sysctl.c:978 [inline] [<ffffffff816fef49>] get_subdir fs/proc/proc_sysctl.c:1022 [inline] [<ffffffff816fef49>] __register_sysctl_table+0x5a9/0x7f0 fs/proc/proc_sysctl.c:1373 [<ffffffff82219b7a>] setup_mq_sysctls+0x12a/0x1c0 ipc/mq_sysctl.c:112 [<ffffffff822197f2>] create_ipc_ns ipc/namespace.c:63 [inline] [<ffffffff822197f2>] copy_ipcs+0x292/0x390 ipc/namespace.c:91 [<ffffffff8127de7c>] create_new_namespaces+0xdc/0x4f0 kernel/nsproxy.c:90 [<ffffffff8127e89b>] unshare_nsproxy_namespaces+0x9b/0x120 kernel/nsproxy.c:226 [<ffffffff8123f92e>] ksys_unshare+0x2fe/0x600 kernel/fork.c:3165 [<ffffffff8123fc42>] __do_sys_unshare kernel/fork.c:3236 [inline] [<ffffffff8123fc42>] __se_sys_unshare kernel/fork.c:3234 [inline] [<ffffffff8123fc42>] __x64_sys_unshare+0x12/0x20 kernel/fork.c:3234 [<ffffffff845aab45>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff845aab45>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [<ffffffff8460006a>] 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: [<ffffffff816fef49>] kmalloc include/linux/slab.h:605 [inline] [<ffffffff816fef49>] kzalloc include/linux/slab.h:733 [inline] [<ffffffff816fef49>] new_dir fs/proc/proc_sysctl.c:978 [inline] [<ffffffff816fef49>] get_subdir fs/proc/proc_sysctl.c:1022 [inline] [<ffffffff816fef49>] __register_sysctl_table+0x5a9/0x7f0 fs/proc/proc_sysctl.c:1373 [<ffffffff82219b7a>] setup_mq_sysctls+0x12a/0x1c0 ipc/mq_sysctl.c:112 [<ffffffff822197f2>] create_ipc_ns ipc/namespace.c:63 [inline] [<ffffffff822197f2>] copy_ipcs+0x292/0x390 ipc/namespace.c:91 [<ffffffff8127de7c>] create_new_namespaces+0xdc/0x4f0 kernel/nsproxy.c:90 [<ffffffff8127e89b>] unshare_nsproxy_namespaces+0x9b/0x120 kernel/nsproxy.c:226 [<ffffffff8123f92e>] ksys_unshare+0x2fe/0x600 kernel/fork.c:3165 [<ffffffff8123fc42>] __do_sys_unshare kernel/fork.c:3236 [inline] [<ffffffff8123fc42>] __se_sys_unshare kernel/fork.c:3234 [inline] [<ffffffff8123fc42>] __x64_sys_unshare+0x12/0x20 kernel/fork.c:3234 [<ffffffff845aab45>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff845aab45>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [<ffffffff8460006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

Reported-by: syzbot+b4b0d1b35442afbf6fd2@syzkaller.appspotmail.com Signed-off-by: Alexey Gladkov legion@kernel.org Link: https://lkml.kernel.org/r/000000000000f5004705e1db8bad@google.com Link: https://lkml.kernel.org/r/20220622200729.2639663-1-legion@kernel.org Signed-off-by: Eric W. Biederman ebiederm@xmission.com

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);