[PATCH 062/100] ipv4 igmp: use in_dev_put in timer handlers instead of __in_dev_put

From: Luis Henriques
Date: Fri Oct 11 2013 - 06:56:24 EST


3.5.7.23 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Salam Noureddine <noureddine@xxxxxxxxxxxxxxxxxx>

commit e2401654dd0f5f3fb7a8d80dad9554d73d7ca394 upstream.

It is possible for the timer handlers to run after the call to
ip_mc_down so use in_dev_put instead of __in_dev_put in the handler
function in order to do proper cleanup when the refcnt reaches 0.
Otherwise, the refcnt can reach zero without the in_device being
destroyed and we end up leaking a reference to the net_device and
see messages like the following,

unregister_netdevice: waiting for eth0 to become free. Usage count = 1

Tested on linux-3.4.43.

Signed-off-by: Salam Noureddine <noureddine@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
net/ipv4/igmp.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index ca66431..be7dba8 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -709,7 +709,7 @@ static void igmp_gq_timer_expire(unsigned long data)

in_dev->mr_gq_running = 0;
igmpv3_send_report(in_dev, NULL);
- __in_dev_put(in_dev);
+ in_dev_put(in_dev);
}

static void igmp_ifc_timer_expire(unsigned long data)
@@ -721,7 +721,7 @@ static void igmp_ifc_timer_expire(unsigned long data)
in_dev->mr_ifc_count--;
igmp_ifc_start_timer(in_dev, IGMP_Unsolicited_Report_Interval);
}
- __in_dev_put(in_dev);
+ in_dev_put(in_dev);
}

static void igmp_ifc_event(struct in_device *in_dev)
--
1.8.3.2

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