From 76518d3798855242817e8a8ed76b2d72f4415624 Mon Sep 17 00:00:00 2001 From: Bernd Edlinger Date: Fri, 20 Mar 2020 21:27:41 +0100 Subject: proc: io_accounting: Use new infrastructure to fix deadlocks in execve 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 Signed-off-by: Eric W. Biederman --- fs/proc/base.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/proc/base.c') diff --git a/fs/proc/base.c b/fs/proc/base.c index a278fda0458b..74f948a6b621 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2883,7 +2883,7 @@ 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; @@ -2919,7 +2919,7 @@ 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; } -- cgit 1.4.1