4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: zhongjiang <[email protected]> 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. [[email protected]: tweak comment] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: zhongjiang <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Xishi Qiu <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Cc: Guenter Roeck <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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,
