From 04103c29b6cc1ffcf9efe167a07e882be68f8367 Mon Sep 17 00:00:00 2001 From: zhongjiang Date: Mon, 10 Jul 2017 15:53:01 -0700 Subject: kernel/exit.c: avoid undefined behaviour when calling wait4() 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 Cc: Oleg Nesterov Cc: David Rientjes Cc: Aneesh Kumar K.V Cc: Kirill A. Shutemov Cc: Xishi Qiu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- kernel/exit.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/exit.c b/kernel/exit.c index 3076f3089919..6dd7ff4b337a 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1662,6 +1662,10 @@ SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr, __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) { -- cgit v1.2.3