The shutdown code only stopped the PHYs but does not diconnect them
properly. This could lead to null pointer deref related kernel oopses
during reboot. Fix this by calling phy_disconnect() after the PHYs are
stopped.
Signed-off-by: John Crispin <[email protected]>
---
net/dsa/slave.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 68714a5..725d9f7 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -154,8 +154,10 @@ static int dsa_slave_close(struct net_device *dev)
struct net_device *master = p->parent->dst->master_netdev;
struct dsa_switch *ds = p->parent;
- if (p->phy)
+ if (p->phy) {
phy_stop(p->phy);
+ phy_disconnect(p->phy);
+ }
dev_mc_unsync(master, dev);
dev_uc_unsync(master, dev);
--
1.7.10.4
On Tue, Oct 18, 2016 at 02:12:40PM +0200, John Crispin wrote:
> The shutdown code only stopped the PHYs but does not diconnect them
> properly. This could lead to null pointer deref related kernel oopses
> during reboot. Fix this by calling phy_disconnect() after the PHYs are
> stopped.
Humm, i don't follow this.
The phy is disconnected in dsa_slave_destroy(). Why is that not
sufficient?
Also, after calling dsa_slave_close(), dsa_slave_open() can be
called. But with your change, the phy has gone, so we are going to
have trouble.
Andrew
>
> Signed-off-by: John Crispin <[email protected]>
> ---
> net/dsa/slave.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/net/dsa/slave.c b/net/dsa/slave.c
> index 68714a5..725d9f7 100644
> --- a/net/dsa/slave.c
> +++ b/net/dsa/slave.c
> @@ -154,8 +154,10 @@ static int dsa_slave_close(struct net_device *dev)
> struct net_device *master = p->parent->dst->master_netdev;
> struct dsa_switch *ds = p->parent;
>
> - if (p->phy)
> + if (p->phy) {
> phy_stop(p->phy);
> + phy_disconnect(p->phy);
> + }
>
> dev_mc_unsync(master, dev);
> dev_uc_unsync(master, dev);
> --
> 1.7.10.4
>
On 18/10/2016 14:29, Andrew Lunn wrote:
> On Tue, Oct 18, 2016 at 02:12:40PM +0200, John Crispin wrote:
>> The shutdown code only stopped the PHYs but does not diconnect them
>> properly. This could lead to null pointer deref related kernel oopses
>> during reboot. Fix this by calling phy_disconnect() after the PHYs are
>> stopped.
>
> Humm, i don't follow this.
>
> The phy is disconnected in dsa_slave_destroy(). Why is that not
> sufficient?
>
> Also, after calling dsa_slave_close(), dsa_slave_open() can be
> called. But with your change, the phy has gone, so we are going to
> have trouble.
>
> Andrew
>
Hi Andrew
i am testing on v4.4 which did not have a phy_disconnect() call. this
seems to have been fixed by cda5c15b so please ignore this patch
John
>>
>> Signed-off-by: John Crispin <[email protected]>
>> ---
>> net/dsa/slave.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/net/dsa/slave.c b/net/dsa/slave.c
>> index 68714a5..725d9f7 100644
>> --- a/net/dsa/slave.c
>> +++ b/net/dsa/slave.c
>> @@ -154,8 +154,10 @@ static int dsa_slave_close(struct net_device *dev)
>> struct net_device *master = p->parent->dst->master_netdev;
>> struct dsa_switch *ds = p->parent;
>>
>> - if (p->phy)
>> + if (p->phy) {
>> phy_stop(p->phy);
>> + phy_disconnect(p->phy);
>> + }
>>
>> dev_mc_unsync(master, dev);
>> dev_uc_unsync(master, dev);
>> --
>> 1.7.10.4
>>
> Hi Andrew
>
> i am testing on v4.4 which did not have a phy_disconnect() call. this
> seems to have been fixed by cda5c15b so please ignore this patch
Hi John
All patches must be against net-next, or net if it is a fix. Anything
else is wrong....
Andrew
On 18/10/2016 15:24, Andrew Lunn wrote:
>> Hi Andrew
>>
>> i am testing on v4.4 which did not have a phy_disconnect() call. this
>> seems to have been fixed by cda5c15b so please ignore this patch
>
> Hi John
>
> All patches must be against net-next, or net if it is a fix. Anything
> else is wrong....
>
> Andrew
>
Hi Andrew,
i know. i was testing on v4.4 and then rebased the patch against
net-next without noticing that a similar patch had already been merged.
regardless, using the latest net-next tree, the oops is gone without
adding any patches.
John