4.9-stable review patch. If anyone has any objections, please let me know.
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From: zhongjiang zhongjiang@huawei.com
commit 4ea77014af0d6205b05503d1c7aac6eace11d473 upstream.
When running kill(72057458746458112, 0) in userspace I hit the following issue.
UBSAN: Undefined behaviour in kernel/signal.c:1462:11 negation of -2147483648 cannot be represented in type 'int': CPU: 226 PID: 9849 Comm: test Tainted: G B ---- ------- 3.10.0-327.53.58.70.x86_64_ubsan+ #116 Hardware name: Huawei Technologies Co., Ltd. RH8100 V3/BC61PBIA, BIOS BLHSV028 11/11/2014 Call Trace: dump_stack+0x19/0x1b ubsan_epilogue+0xd/0x50 __ubsan_handle_negate_overflow+0x109/0x14e SYSC_kill+0x43e/0x4d0 SyS_kill+0xe/0x10 system_call_fastpath+0x16/0x1b
Add code to avoid the UBSAN detection.
[akpm@linux-foundation.org: tweak comment] Link: http://lkml.kernel.org/r/1496670008-59084-1-git-send-email-zhongjiang@huawei... Signed-off-by: zhongjiang zhongjiang@huawei.com Cc: Oleg Nesterov oleg@redhat.com Cc: Michal Hocko mhocko@kernel.org Cc: Vlastimil Babka vbabka@suse.cz Cc: Xishi Qiu qiuxishi@huawei.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Cc: Guenter Roeck linux@roeck-us.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/signal.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/kernel/signal.c +++ b/kernel/signal.c @@ -1392,6 +1392,10 @@ static int kill_something_info(int sig, return ret; }
+ /* -INT_MIN is undefined. Exclude this case to avoid a UBSAN warning */ + if (pid == INT_MIN) + return -ESRCH; + read_lock(&tasklist_lock); if (pid != -1) { ret = __kill_pgrp_info(sig, info,