| Message ID | 1568824395-4162-1-git-send-email-allen.pais@oracle.com |
|---|---|
| State | Changes Requested |
| Delegated to: | David Miller |
| Headers | show |
| Series | drivers/net/fjes: fix a potential NULL pointer dereference | expand |
On Wed, 18 Sep 2019 22:03:15 +0530, Allen Pais wrote: > alloc_workqueue is not checked for errors and as a result, > a potential NULL dereference could occur. > > Signed-off-by: Allen Pais <allen.pais@oracle.com> If I'm looking at this right you are jumping to err_free_netdev without setting the err variable. It must had been set to 0 from the return of fjes_sw_init(). This means we will free the netdev, and return 0. This means probe will not fail and driver's remove function will be run at some point. fjes_remove it will try to free the netdev again. Looks like there's another existing bug here in that the work queues are not free when something fails in fjes_probe, just the netdev. Once you untangle that, and before you post a v2, could you please try to identify which commit introduced the regression and provide an appropriate "Fixes" tag? > diff --git a/drivers/net/fjes/fjes_main.c b/drivers/net/fjes/fjes_main.c > index bbbc1dc..2d04104 100644 > --- a/drivers/net/fjes/fjes_main.c > +++ b/drivers/net/fjes/fjes_main.c > @@ -1237,8 +1237,15 @@ static int fjes_probe(struct platform_device *plat_dev) > adapter->open_guard = false; > > adapter->txrx_wq = alloc_workqueue(DRV_NAME "/txrx", WQ_MEM_RECLAIM, 0); > + if (unlikely(!adapter->txrx_wq)) > + goto err_free_netdev; > + > adapter->control_wq = alloc_workqueue(DRV_NAME "/control", > WQ_MEM_RECLAIM, 0); > + if (unlikely(!adapter->control_wq)) { > + destroy_workqueue(adapter->txrx_wq); > + goto err_free_netdev; > + } > > INIT_WORK(&adapter->tx_stall_task, fjes_tx_stall_task); > INIT_WORK(&adapter->raise_intr_rxdata_task,
> > If I'm looking at this right you are jumping to err_free_netdev without > setting the err variable. It must had been set to 0 from the return of > fjes_sw_init(). This means we will free the netdev, and return 0. This > means probe will not fail and driver's remove function will be run > at some point. fjes_remove it will try to free the netdev again. Good catch. Here's a quick diff what I should have done, --- a/drivers/net/fjes/fjes_main.c +++ b/drivers/net/fjes/fjes_main.c @@ -1236,9 +1236,21 @@ static int fjes_probe(struct platform_device *plat_dev) adapter->force_reset = false; adapter->open_guard = false; + /* Re-initialize err to -ENOMEM to handle workqueue allocation failures, + and we don't return 0 on failure. + */ + err = -ENOMEM; + adapter->txrx_wq = alloc_workqueue(DRV_NAME "/txrx", WQ_MEM_RECLAIM, 0); + if (unlikely(!adapter->txrx_wq)) + goto err_free_netdev; + adapter->control_wq = alloc_workqueue(DRV_NAME "/control", WQ_MEM_RECLAIM, 0); + if (unlikely(!adapter->control_wq)) { + destroy_workqueue(adapter->txrx_wq); + goto err_free_netdev; + } > Looks like there's another existing bug here in that the work queues > are not free when something fails in fjes_probe, just the netdev. I shall look into it and send out a separate fix. > Once you untangle that, and before you post a v2, could you please try > to identify which commit introduced the regression and provide an > appropriate "Fixes" tag? > Fixes: f2edc4e1b078("net: fjes: fjes_main: Remove create_workqueue") - Allen
diff --git a/drivers/net/fjes/fjes_main.c b/drivers/net/fjes/fjes_main.c index bbbc1dc..2d04104 100644 --- a/drivers/net/fjes/fjes_main.c +++ b/drivers/net/fjes/fjes_main.c @@ -1237,8 +1237,15 @@ static int fjes_probe(struct platform_device *plat_dev) adapter->open_guard = false; adapter->txrx_wq = alloc_workqueue(DRV_NAME "/txrx", WQ_MEM_RECLAIM, 0); + if (unlikely(!adapter->txrx_wq)) + goto err_free_netdev; + adapter->control_wq = alloc_workqueue(DRV_NAME "/control", WQ_MEM_RECLAIM, 0); + if (unlikely(!adapter->control_wq)) { + destroy_workqueue(adapter->txrx_wq); + goto err_free_netdev; + } INIT_WORK(&adapter->tx_stall_task, fjes_tx_stall_task); INIT_WORK(&adapter->raise_intr_rxdata_task,
alloc_workqueue is not checked for errors and as a result, a potential NULL dereference could occur. Signed-off-by: Allen Pais <allen.pais@oracle.com> --- drivers/net/fjes/fjes_main.c | 7 +++++++ 1 file changed, 7 insertions(+)