| From dd83c161fbcc5d8be637ab159c0de015cbff5ba4 Mon Sep 17 00:00:00 2001 |
| From: zhongjiang <zhongjiang@huawei.com> |
| Date: Mon, 10 Jul 2017 15:53:01 -0700 |
| Subject: kernel/exit.c: avoid undefined behaviour when calling wait4() |
| |
| From: zhongjiang <zhongjiang@huawei.com> |
| |
| commit dd83c161fbcc5d8be637ab159c0de015cbff5ba4 upstream. |
| |
| wait4(-2147483648, 0x20, 0, 0xdd0000) triggers: |
| UBSAN: Undefined behaviour in kernel/exit.c:1651:9 |
| |
| The related calltrace is as follows: |
| |
| negation of -2147483648 cannot be represented in type 'int': |
| CPU: 9 PID: 16482 Comm: zj Tainted: G B ---- ------- 3.10.0-327.53.58.71.x86_64+ #66 |
| Hardware name: Huawei Technologies Co., Ltd. Tecal RH2285 /BC11BTSA , BIOS CTSAV036 04/27/2011 |
| Call Trace: |
| dump_stack+0x19/0x1b |
| ubsan_epilogue+0xd/0x50 |
| __ubsan_handle_negate_overflow+0x109/0x14e |
| SyS_wait4+0x1cb/0x1e0 |
| system_call_fastpath+0x16/0x1b |
| |
| Exclude the overflow to avoid the UBSAN warning. |
| |
| Link: http://lkml.kernel.org/r/1497264618-20212-1-git-send-email-zhongjiang@huawei.com |
| Signed-off-by: zhongjiang <zhongjiang@huawei.com> |
| Cc: Oleg Nesterov <oleg@redhat.com> |
| Cc: David Rientjes <rientjes@google.com> |
| Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> |
| Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> |
| Cc: Xishi Qiu <qiuxishi@huawei.com> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| kernel/exit.c | 4 ++++ |
| 1 file changed, 4 insertions(+) |
| |
| --- a/kernel/exit.c |
| +++ b/kernel/exit.c |
| @@ -1620,6 +1620,10 @@ SYSCALL_DEFINE4(wait4, pid_t, upid, int |
| __WNOTHREAD|__WCLONE|__WALL)) |
| return -EINVAL; |
| |
| + /* -INT_MIN is not defined */ |
| + if (upid == INT_MIN) |
| + return -ESRCH; |
| + |
| if (upid == -1) |
| type = PIDTYPE_MAX; |
| else if (upid < 0) { |
