[PATCH 1/2] net: pktgen: fix race between pktgen_thread_worker() and kthread_stop()

From: Oleg Nesterov
Date: Wed Jul 08 2015 - 15:44:08 EST


pktgen_thread_worker() is obviously racy, kthread_stop() can come
between the kthread_should_stop() check and set_current_state().

Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Reported-by: Jan Stancek <jstancek@xxxxxxxxxx>
Reported-by: Marcelo Leitner <mleitner@xxxxxxxxxx>
---
net/core/pktgen.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 508155b..043ea18 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -3490,8 +3490,10 @@ static int pktgen_thread_worker(void *arg)
pktgen_rem_thread(t);

/* Wait for kthread_stop */
- while (!kthread_should_stop()) {
+ for (;;) {
set_current_state(TASK_INTERRUPTIBLE);
+ if (kthread_should_stop())
+ break;
schedule();
}
__set_current_state(TASK_RUNNING);
--
1.5.5.1

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