From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit d7c04b05c9ca14c55309eb139430283a45c4c25f ]
When host is under high stress, it is very possible thread
running netdev_wait_allrefs() returns from msleep(250)
10 seconds late.
This leads to these messages in the syslog :
[...] unregister_netdevice: waiting for syz_tun to become free. Usage count = 0
If the device refcount is zero, the wait is over.
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/core/dev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -8716,7 +8716,7 @@ static void netdev_wait_allrefs(struct n
refcnt = netdev_refcnt_read(dev);
- if (time_after(jiffies, warning_time + 10 * HZ)) {
+ if (refcnt && time_after(jiffies, warning_time + 10 * HZ)) {
pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
dev->name, refcnt);
warning_time = jiffies;
