From db7cfc380900bc4243b09623fd72fabe0a8ff23b Mon Sep 17 00:00:00 2001 From: Alexey Gladkov 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: [] 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 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 --- ipc/namespace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/ipc/namespace.c b/ipc/namespace.c index 754f323..e1fcaed 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); -- 2.7.4