Messages in this thread | | | Date | Sun, 19 Dec 2021 09:29:48 +0000 | From | Martin Habets <> | Subject | Re: [PATCH v2] sfc: falcon: potential dereference null pointer of rx_queue->page_ring |
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On Fri, Dec 17, 2021 at 10:33:08PM +0800, Jiasheng Jiang wrote: > The return value of kcalloc() needs to be checked.
Your predicate is wrong. The code that uses rx_queue->page_ring can deal with it being NULL. The only thing you might want to do is set rx_queue->page_ptr_mask to 0.
Martin
> To avoid dereference of null pointer in case of the failure of alloc. > Therefore, it might be better to change the return type of > ef4_init_rx_recycle_ring(), ef4_init_rx_queue(), ef4_start_datapath(), > ef4_start_all(), and return -ENOMEM when alloc fails and return 0 the > others. > Also, ef4_realloc_channels(), ef4_net_open(), ef4_change_mtu(), > ef4_reset_up() and ef4_pm_thaw() should deal with the return value of > ef4_start_all(). > > Fixes: 5a6681e22c14 ("sfc: separate out SFC4000 ("Falcon") support into new sfc-falcon driver") > Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn> > --- > Changelog: > > v1 -> v2 > > *Change 1. Alter the "ret" to 'rc' and cleanup the rx_queue and tx_queue > when alloc fails. > --- > drivers/net/ethernet/sfc/falcon/efx.c | 56 +++++++++++++++++++++------ > drivers/net/ethernet/sfc/falcon/efx.h | 2 +- > drivers/net/ethernet/sfc/falcon/rx.c | 18 +++++++-- > 3 files changed, 60 insertions(+), 16 deletions(-) > > diff --git a/drivers/net/ethernet/sfc/falcon/efx.c b/drivers/net/ethernet/sfc/falcon/efx.c > index 5e7a57b680ca..89b93ed08251 100644 > --- a/drivers/net/ethernet/sfc/falcon/efx.c > +++ b/drivers/net/ethernet/sfc/falcon/efx.c > @@ -201,7 +201,7 @@ static void ef4_init_napi_channel(struct ef4_channel *channel); > static void ef4_fini_napi(struct ef4_nic *efx); > static void ef4_fini_napi_channel(struct ef4_channel *channel); > static void ef4_fini_struct(struct ef4_nic *efx); > -static void ef4_start_all(struct ef4_nic *efx); > +static int ef4_start_all(struct ef4_nic *efx); > static void ef4_stop_all(struct ef4_nic *efx); > > #define EF4_ASSERT_RESET_SERIALISED(efx) \ > @@ -590,7 +590,7 @@ static int ef4_probe_channels(struct ef4_nic *efx) > * to propagate configuration changes (mtu, checksum offload), or > * to clear hardware error conditions > */ > -static void ef4_start_datapath(struct ef4_nic *efx) > +static int ef4_start_datapath(struct ef4_nic *efx) > { > netdev_features_t old_features = efx->net_dev->features; > bool old_rx_scatter = efx->rx_scatter; > @@ -598,6 +598,7 @@ static void ef4_start_datapath(struct ef4_nic *efx) > struct ef4_rx_queue *rx_queue; > struct ef4_channel *channel; > size_t rx_buf_len; > + int rc; > > /* Calculate the rx buffer allocation parameters required to > * support the current MTU, including padding for header > @@ -668,7 +669,10 @@ static void ef4_start_datapath(struct ef4_nic *efx) > } > > ef4_for_each_channel_rx_queue(rx_queue, channel) { > - ef4_init_rx_queue(rx_queue); > + rc = ef4_init_rx_queue(rx_queue); > + if (rc) > + goto fail; > + > atomic_inc(&efx->active_queues); > ef4_stop_eventq(channel); > ef4_fast_push_rx_descriptors(rx_queue, false); > @@ -680,6 +684,17 @@ static void ef4_start_datapath(struct ef4_nic *efx) > > if (netif_device_present(efx->net_dev)) > netif_tx_wake_all_queues(efx->net_dev); > + > + return 0; > + > +fail: > + ef4_for_each_channel(channel, efx) { > + ef4_for_each_channel_rx_queue(rx_queue, channel) > + ef4_fini_rx_queue(rx_queue); > + ef4_for_each_possible_channel_tx_queue(tx_queue, channel) > + ef4_fini_tx_queue(tx_queue); > + } > + return rc; > } > > static void ef4_stop_datapath(struct ef4_nic *efx) > @@ -853,7 +868,10 @@ ef4_realloc_channels(struct ef4_nic *efx, u32 rxq_entries, u32 txq_entries) > "unable to restart interrupts on channel reallocation\n"); > ef4_schedule_reset(efx, RESET_TYPE_DISABLE); > } else { > - ef4_start_all(efx); > + rc = ef4_start_all(efx); > + if (rc) > + return rc; > + > netif_device_attach(efx->net_dev); > } > return rc; > @@ -1814,8 +1832,10 @@ static int ef4_probe_all(struct ef4_nic *efx) > * is safe to call multiple times, so long as the NIC is not disabled. > * Requires the RTNL lock. > */ > -static void ef4_start_all(struct ef4_nic *efx) > +static int ef4_start_all(struct ef4_nic *efx) > { > + int rc; > + > EF4_ASSERT_RESET_SERIALISED(efx); > BUG_ON(efx->state == STATE_DISABLED); > > @@ -1823,10 +1843,12 @@ static void ef4_start_all(struct ef4_nic *efx) > * of these flags are safe to read under just the rtnl lock */ > if (efx->port_enabled || !netif_running(efx->net_dev) || > efx->reset_pending) > - return; > + return 0; > > ef4_start_port(efx); > - ef4_start_datapath(efx); > + rc = ef4_start_datapath(efx); > + if (rc) > + return rc; > > /* Start the hardware monitor if there is one */ > if (efx->type->monitor != NULL) > @@ -1838,6 +1860,8 @@ static void ef4_start_all(struct ef4_nic *efx) > spin_lock_bh(&efx->stats_lock); > efx->type->update_stats(efx, NULL, NULL); > spin_unlock_bh(&efx->stats_lock); > + > + return 0; > } > > /* Quiesce the hardware and software data path, and regular activity > @@ -2074,7 +2098,10 @@ int ef4_net_open(struct net_device *net_dev) > * before the monitor starts running */ > ef4_link_status_changed(efx); > > - ef4_start_all(efx); > + rc = ef4_start_all(efx); > + if (rc) > + return rc; > + > ef4_selftest_async_start(efx); > return 0; > } > @@ -2140,7 +2167,10 @@ static int ef4_change_mtu(struct net_device *net_dev, int new_mtu) > ef4_mac_reconfigure(efx); > mutex_unlock(&efx->mac_lock); > > - ef4_start_all(efx); > + rc = ef4_start_all(efx); > + if (rc) > + return rc; > + > netif_device_attach(efx->net_dev); > return 0; > } > @@ -2409,7 +2439,9 @@ int ef4_reset_up(struct ef4_nic *efx, enum reset_type method, bool ok) > > mutex_unlock(&efx->mac_lock); > > - ef4_start_all(efx); > + rc = ef4_start_all(efx); > + if (rc) > + return rc; > > return 0; > > @@ -3033,7 +3065,9 @@ static int ef4_pm_thaw(struct device *dev) > efx->phy_op->reconfigure(efx); > mutex_unlock(&efx->mac_lock); > > - ef4_start_all(efx); > + rc = ef4_start_all(efx); > + if (rc) > + goto fail; > > netif_device_attach(efx->net_dev); > > diff --git a/drivers/net/ethernet/sfc/falcon/efx.h b/drivers/net/ethernet/sfc/falcon/efx.h > index d3b4646545fa..483501b42667 100644 > --- a/drivers/net/ethernet/sfc/falcon/efx.h > +++ b/drivers/net/ethernet/sfc/falcon/efx.h > @@ -39,7 +39,7 @@ void ef4_set_default_rx_indir_table(struct ef4_nic *efx); > void ef4_rx_config_page_split(struct ef4_nic *efx); > int ef4_probe_rx_queue(struct ef4_rx_queue *rx_queue); > void ef4_remove_rx_queue(struct ef4_rx_queue *rx_queue); > -void ef4_init_rx_queue(struct ef4_rx_queue *rx_queue); > +int ef4_init_rx_queue(struct ef4_rx_queue *rx_queue); > void ef4_fini_rx_queue(struct ef4_rx_queue *rx_queue); > void ef4_fast_push_rx_descriptors(struct ef4_rx_queue *rx_queue, bool atomic); > void ef4_rx_slow_fill(struct timer_list *t); > diff --git a/drivers/net/ethernet/sfc/falcon/rx.c b/drivers/net/ethernet/sfc/falcon/rx.c > index 966f13e7475d..6042219ddb2f 100644 > --- a/drivers/net/ethernet/sfc/falcon/rx.c > +++ b/drivers/net/ethernet/sfc/falcon/rx.c > @@ -709,8 +709,8 @@ int ef4_probe_rx_queue(struct ef4_rx_queue *rx_queue) > return rc; > } > > -static void ef4_init_rx_recycle_ring(struct ef4_nic *efx, > - struct ef4_rx_queue *rx_queue) > +static int ef4_init_rx_recycle_ring(struct ef4_nic *efx, > + struct ef4_rx_queue *rx_queue) > { > unsigned int bufs_in_recycle_ring, page_ring_size; > > @@ -728,13 +728,19 @@ static void ef4_init_rx_recycle_ring(struct ef4_nic *efx, > efx->rx_bufs_per_page); > rx_queue->page_ring = kcalloc(page_ring_size, > sizeof(*rx_queue->page_ring), GFP_KERNEL); > + if (!rx_queue->page_ring) > + return -ENOMEM; > + > rx_queue->page_ptr_mask = page_ring_size - 1; > + > + return 0; > } > > -void ef4_init_rx_queue(struct ef4_rx_queue *rx_queue) > +int ef4_init_rx_queue(struct ef4_rx_queue *rx_queue) > { > struct ef4_nic *efx = rx_queue->efx; > unsigned int max_fill, trigger, max_trigger; > + int rc; > > netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev, > "initialising RX queue %d\n", ef4_rx_queue_index(rx_queue)); > @@ -744,7 +750,9 @@ void ef4_init_rx_queue(struct ef4_rx_queue *rx_queue) > rx_queue->notified_count = 0; > rx_queue->removed_count = 0; > rx_queue->min_fill = -1U; > - ef4_init_rx_recycle_ring(efx, rx_queue); > + rc = ef4_init_rx_recycle_ring(efx, rx_queue); > + if (rc) > + return rc; > > rx_queue->page_remove = 0; > rx_queue->page_add = rx_queue->page_ptr_mask + 1; > @@ -770,6 +778,8 @@ void ef4_init_rx_queue(struct ef4_rx_queue *rx_queue) > > /* Set up RX descriptor ring */ > ef4_nic_init_rx(rx_queue); > + > + return 0; > } > > void ef4_fini_rx_queue(struct ef4_rx_queue *rx_queue) > -- > 2.25.1
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