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authorzhongjiang <zhongjiang@huawei.com>2017-07-10 15:52:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-10 16:32:36 -0700
commit4ea77014af0d6205b05503d1c7aac6eace11d473 (patch)
tree860140f1617a9fa261479689522c2133437e1f6f /kernel
parent67c6777a5d331dda32a4c4a1bf0cac85bdaaaed8 (diff)
downloadlwn-4ea77014af0d6205b05503d1c7aac6eace11d473.tar.gz
lwn-4ea77014af0d6205b05503d1c7aac6eace11d473.zip
kernel/signal.c: avoid undefined behaviour in kill_something_info
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.com 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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/signal.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index 48a59eefd8ad..caed9133ae52 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1402,6 +1402,10 @@ static int kill_something_info(int sig, struct siginfo *info, pid_t pid)
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,