| Message ID | bd466d82-db03-38b1-0a13-86aa124680ea@kontron.de (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | can: mcp251x: Fix resume from sleep before interface was brought up | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Series ignored based on subject |
On Tue, May 04, 2021 at 06:01:48PM +0200, Schrempf Frieder wrote: > Since 8ce8c0abcba3 the driver queues work via priv->restart_work when > resuming after suspend, even when the interface was not previously > enabled. This causes a null dereference error as the workqueue is > only allocated and initialized in mcp251x_open(). > > To fix this we move the workqueue init to mcp251x_can_probe() as > there is no reason to do it later and repeat it whenever > mcp251x_open() is called. AFAIU the IRQ is freed at ->ndo_stop() which is guaranteed to be called before ->remove(). If it's the case, we are fine. FWIW, Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Fixes: 8ce8c0abcba3 ("can: mcp251x: only reset hardware as required") > Cc: stable@vger.kernel.org > Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de> > --- > drivers/net/can/spi/mcp251x.c | 25 ++++++++++++++----------- > 1 file changed, 14 insertions(+), 11 deletions(-) > > diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c > index a57da43680d8..42e8e5791c9f 100644 > --- a/drivers/net/can/spi/mcp251x.c > +++ b/drivers/net/can/spi/mcp251x.c > @@ -956,8 +956,6 @@ static int mcp251x_stop(struct net_device *net) > > priv->force_quit = 1; > free_irq(spi->irq, priv); > - destroy_workqueue(priv->wq); > - priv->wq = NULL; > > mutex_lock(&priv->mcp_lock); > > @@ -1224,15 +1222,6 @@ static int mcp251x_open(struct net_device *net) > goto out_close; > } > > - priv->wq = alloc_workqueue("mcp251x_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM, > - 0); > - if (!priv->wq) { > - ret = -ENOMEM; > - goto out_clean; > - } > - INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler); > - INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler); > - > ret = mcp251x_hw_wake(spi); > if (ret) > goto out_free_wq; > @@ -1373,6 +1362,15 @@ static int mcp251x_can_probe(struct spi_device *spi) > if (ret) > goto out_clk; > > + priv->wq = alloc_workqueue("mcp251x_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM, > + 0); > + if (!priv->wq) { > + ret = -ENOMEM; > + goto out_clk; > + } > + INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler); > + INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler); > + > priv->spi = spi; > mutex_init(&priv->mcp_lock); > > @@ -1417,6 +1415,8 @@ static int mcp251x_can_probe(struct spi_device *spi) > return 0; > > error_probe: > + destroy_workqueue(priv->wq); > + priv->wq = NULL; > mcp251x_power_enable(priv->power, 0); > > out_clk: > @@ -1438,6 +1438,9 @@ static int mcp251x_can_remove(struct spi_device *spi) > > mcp251x_power_enable(priv->power, 0); > > + destroy_workqueue(priv->wq); > + priv->wq = NULL; > + > clk_disable_unprepare(priv->clk); > > free_candev(net); > -- > 2.25.1 > >
On 04.05.2021 18:01:48, Schrempf Frieder wrote: > Since 8ce8c0abcba3 the driver queues work via priv->restart_work when > resuming after suspend, even when the interface was not previously > enabled. This causes a null dereference error as the workqueue is > only allocated and initialized in mcp251x_open(). > > To fix this we move the workqueue init to mcp251x_can_probe() as > there is no reason to do it later and repeat it whenever > mcp251x_open() is called. > > Fixes: 8ce8c0abcba3 ("can: mcp251x: only reset hardware as required") > Cc: stable@vger.kernel.org > Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de> Added to linux-can/testing. Thanks, Marc
> On 04.05.2021 18:01:48, Schrempf Frieder wrote: >> Fixes: 8ce8c0abcba3 ("can: mcp251x: only reset hardware as required") >> Cc: stable@vger.kernel.org >> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de> Thanks for finding and fixing this and sorry for introducing the bug. Regards Timo
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index a57da43680d8..42e8e5791c9f 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -956,8 +956,6 @@ static int mcp251x_stop(struct net_device *net) priv->force_quit = 1; free_irq(spi->irq, priv); - destroy_workqueue(priv->wq); - priv->wq = NULL; mutex_lock(&priv->mcp_lock); @@ -1224,15 +1222,6 @@ static int mcp251x_open(struct net_device *net) goto out_close; } - priv->wq = alloc_workqueue("mcp251x_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM, - 0); - if (!priv->wq) { - ret = -ENOMEM; - goto out_clean; - } - INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler); - INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler); - ret = mcp251x_hw_wake(spi); if (ret) goto out_free_wq; @@ -1373,6 +1362,15 @@ static int mcp251x_can_probe(struct spi_device *spi) if (ret) goto out_clk; + priv->wq = alloc_workqueue("mcp251x_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM, + 0); + if (!priv->wq) { + ret = -ENOMEM; + goto out_clk; + } + INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler); + INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler); + priv->spi = spi; mutex_init(&priv->mcp_lock); @@ -1417,6 +1415,8 @@ static int mcp251x_can_probe(struct spi_device *spi) return 0; error_probe: + destroy_workqueue(priv->wq); + priv->wq = NULL; mcp251x_power_enable(priv->power, 0); out_clk: @@ -1438,6 +1438,9 @@ static int mcp251x_can_remove(struct spi_device *spi) mcp251x_power_enable(priv->power, 0); + destroy_workqueue(priv->wq); + priv->wq = NULL; + clk_disable_unprepare(priv->clk); free_candev(net);
Since 8ce8c0abcba3 the driver queues work via priv->restart_work when resuming after suspend, even when the interface was not previously enabled. This causes a null dereference error as the workqueue is only allocated and initialized in mcp251x_open(). To fix this we move the workqueue init to mcp251x_can_probe() as there is no reason to do it later and repeat it whenever mcp251x_open() is called. Fixes: 8ce8c0abcba3 ("can: mcp251x: only reset hardware as required") Cc: stable@vger.kernel.org Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de> --- drivers/net/can/spi/mcp251x.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-)