lkml.org 
[lkml]   [2020]   [Sep]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.4 197/388] proc: io_accounting: Use new infrastructure to fix deadlocks in execve
Date
From: Bernd Edlinger <bernd.edlinger@hotmail.de>

[ Upstream commit 76518d3798855242817e8a8ed76b2d72f4415624 ]

This changes do_io_accounting to use the new exec_update_mutex
instead of cred_guard_mutex.

This fixes possible deadlocks when the trace is accessing
/proc/$pid/io for instance.

This should be safe, as the credentials are only used for reading.

Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/proc/base.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 4fdfe4faa74ee..529d0c6ec6f9c 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2770,7 +2770,7 @@ static int do_io_accounting(struct task_struct *task, struct seq_file *m, int wh
unsigned long flags;
int result;

- result = mutex_lock_killable(&task->signal->cred_guard_mutex);
+ result = mutex_lock_killable(&task->signal->exec_update_mutex);
if (result)
return result;

@@ -2806,7 +2806,7 @@ static int do_io_accounting(struct task_struct *task, struct seq_file *m, int wh
result = 0;

out_unlock:
- mutex_unlock(&task->signal->cred_guard_mutex);
+ mutex_unlock(&task->signal->exec_update_mutex);
return result;
}

--
2.25.1


\
 
 \ /
  Last update: 2020-09-29 14:04    [W:0.808 / U:0.788 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site