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From:   "haifeng.xu" <haifeng.xu@shopee.com>
To:     brauner@kernel.org
Cc:     ebiederm@xmission.com, oleg@redhat.com, keescook@chromium.org,
        tglx@linutronix.de, peterz@infradead.org, elver@google.com,
        linux-kernel@vger.kernel.org, "haifeng.xu" <haifeng.xu@shopee.com>
Subject: [PATCH] signal: Initialize the info in ksignal
Date:   Mon, 28 Nov 2022 06:56:06 +0000
Message-Id: <20221128065606.19570-1-haifeng.xu@shopee.com>
MIME-Version: 1.0
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When handing the SIGNAL_GROUP_EXIT flag, the info in ksignal isn't cleared.
However, the info acquired by dequeue_synchronous_signal/dequeue_signal is
initialized and can be safely used. Fortunately, the fatal signal process
just uses the si_signo and doesn't use any other member. Even so, the
initialization before use is more safer.

Signed-off-by: haifeng.xu <haifeng.xu@shopee.com>
---
 kernel/signal.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/signal.c b/kernel/signal.c
index d140672185a4..b9b0c8c620e7 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2693,6 +2693,7 @@ bool get_signal(struct ksignal *ksig)
 		/* Has this task already been marked for death? */
 		if ((signal->flags & SIGNAL_GROUP_EXIT) ||
 		     signal->group_exec_task) {
+			clear_siginfo(&ksig->info);
 			ksig->info.si_signo = signr = SIGKILL;
 			sigdelset(&current->pending.signal, SIGKILL);
 			trace_signal_deliver(SIGKILL, SEND_SIG_NOINFO,
-- 
2.25.1