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Message-ID: <01783b8c-2a39-73ec-c537-cc1df82643e2@huawei.com>
Date:   Sat, 8 Oct 2022 11:05:48 +0800
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To:     Theodore Ts'o <tytso@mit.edu>
CC:     <linux-ext4@vger.kernel.org>, Lukas Czerner <lczerner@redhat.com>,
        <liuzhiqiang26@huawei.com>, linfeilong <linfeilong@huawei.com>
From:   zhanchengbin <zhanchengbin1@huawei.com>
Subject: [PATCH] misc/fsck.c: Processes may kill other processes.
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If run the fsck -N command, processes don't execute, just show what
would be done. However, the pid whose value is -1 is added to the
instance_list list in the execute function,if the kill_all function
is called later, kill(-1, signum) is executed, Signals are sent to
all processes except the number one process and itself. Other
processes will be killed if they use the default signal processing
function.

Signed-off-by: zhanchengbin <zhanchengbin1@huawei.com>
---
  misc/fsck.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/misc/fsck.c b/misc/fsck.c
index 4efe10ec..faf7789d 100644
--- a/misc/fsck.c
+++ b/misc/fsck.c
@@ -546,6 +546,8 @@ static int kill_all(int signum)
  	for (inst = instance_list; inst; inst = inst->next) {
  		if (inst->flags & FLAG_DONE)
  			continue;
+		if (inst->pid == -1)
+			continue;
  		kill(inst->pid, signum);
  		n++;
  	}
-- 
2.27.0