From: Qian Cai <cai@lca.pw>
To: tglx@linutronix.de
Cc: ebiederm@xmission.com, oleg@redhat.com,
linux-kernel@vger.kernel.org, Qian Cai <cai@lca.pw>
Subject: [PATCH -next] posix-cpu-timers: fix memory leaks for task_struct
Date: Tue, 3 Mar 2020 19:43:36 -0500 [thread overview]
Message-ID: <20200304004336.960-1-cai@lca.pw> (raw)
The recent commit removed put_task_struct() in posix_cpu_timer_del()
results in many memory leaks like this,
unreferenced object 0xc0000016d9b44480 (size 8192):
comm "timer_create01", pid 57749, jiffies 4295163733 (age 6159.670s)
hex dump (first 32 bytes):
02 00 00 00 00 00 00 00 10 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000056aca129>] copy_process+0x26c/0x18e0
alloc_task_struct_node at kernel/fork.c:169
(inlined by) dup_task_struct at kernel/fork.c:877
(inlined by) copy_process at kernel/fork.c:1929
[<00000000bdbbf9f8>] _do_fork+0xac/0xb20
[<00000000dcb1c445>] __do_sys_clone+0x98/0xe0
__do_sys_clone at kernel/fork.c:2591
[<000000006c059205>] ppc_clone+0x8/0xc
ppc_clone at arch/powerpc/kernel/entry_64.S:479
Fixes: 672ebe8eb017a5 ("posix-cpu-timers: Store a reference to a pid not a task")
Signed-off-by: Qian Cai <cai@lca.pw>
---
kernel/time/posix-cpu-timers.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index afd1e959a282..e0b580deb61a 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -446,8 +446,10 @@ static int posix_cpu_timer_del(struct k_itimer *timer)
out:
rcu_read_unlock();
- if (!ret)
+ if (!ret) {
put_pid(ctmr->pid);
+ put_task_struct(p);
+ }
return ret;
}
--
2.21.0 (Apple Git-122.2)
next reply other threads:[~2020-03-04 0:43 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-04 0:43 Qian Cai [this message]
2020-03-04 5:15 ` [PATCH -next] posix-cpu-timers: fix memory leaks for task_struct Eric W. Biederman
2020-03-04 5:21 ` [PATCH timers/core] posix-cpu-timers: Put the task_struct in posix_cpu_timers_create Eric W. Biederman
2020-03-04 8:56 ` Thomas Gleixner
2020-03-04 14:32 ` Eric W. Biederman
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