| Message ID | 20211220023715.746815-1-jiasheng@iscas.ac.cn (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v4] sfc: potential dereference null pointer of rx_queue->page_ring | expand |
On Mon, Dec 20, 2021 at 10:37:15AM +0800, Jiasheng Jiang wrote: > The return value of kcalloc() needs to be checked. Maybe my previous reply against v2 crossed with your later versions. 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. It is a mask, never use a signed value for it. Martin > To avoid dereference of null pointer in case of the failure of alloc, > such as efx_fini_rx_recycle_ring(). > Therefore, it should be better to change the definition of page_ptr_mask > to signed int and then assign the page_ptr_mask to -1 when page_ring is > NULL, in order to avoid the use in the loop. > > Fixes: 5a6681e22c14 ("sfc: separate out SFC4000 ("Falcon") support into new sfc-falcon driver") > Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn> > --- > Changelog: > > v3 -> v4 > > *Change 1. Casade return -ENOMEM when alloc fails and deal with the > error. > *Change 2. Set size to -1 instead of return error. > *Change 3. Change the Fixes tag. > --- > drivers/net/ethernet/sfc/net_driver.h | 2 +- > drivers/net/ethernet/sfc/rx_common.c | 5 ++++- > 2 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h > index 9b4b25704271..beba3e0a6027 100644 > --- a/drivers/net/ethernet/sfc/net_driver.h > +++ b/drivers/net/ethernet/sfc/net_driver.h > @@ -407,7 +407,7 @@ struct efx_rx_queue { > unsigned int page_recycle_count; > unsigned int page_recycle_failed; > unsigned int page_recycle_full; > - unsigned int page_ptr_mask; > + int page_ptr_mask; > unsigned int max_fill; > unsigned int fast_fill_trigger; > unsigned int min_fill; > diff --git a/drivers/net/ethernet/sfc/rx_common.c b/drivers/net/ethernet/sfc/rx_common.c > index 68fc7d317693..d9d0a5805f1c 100644 > --- a/drivers/net/ethernet/sfc/rx_common.c > +++ b/drivers/net/ethernet/sfc/rx_common.c > @@ -150,7 +150,10 @@ static void efx_init_rx_recycle_ring(struct efx_rx_queue *rx_queue) > efx->rx_bufs_per_page); > rx_queue->page_ring = kcalloc(page_ring_size, > sizeof(*rx_queue->page_ring), GFP_KERNEL); > - rx_queue->page_ptr_mask = page_ring_size - 1; > + if (!rx_queue->page_ring) > + rx_queue->page_ptr_mask = -1; > + else > + rx_queue->page_ptr_mask = page_ring_size - 1; > } > > static void efx_fini_rx_recycle_ring(struct efx_rx_queue *rx_queue) > -- > 2.25.1
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h index 9b4b25704271..beba3e0a6027 100644 --- a/drivers/net/ethernet/sfc/net_driver.h +++ b/drivers/net/ethernet/sfc/net_driver.h @@ -407,7 +407,7 @@ struct efx_rx_queue { unsigned int page_recycle_count; unsigned int page_recycle_failed; unsigned int page_recycle_full; - unsigned int page_ptr_mask; + int page_ptr_mask; unsigned int max_fill; unsigned int fast_fill_trigger; unsigned int min_fill; diff --git a/drivers/net/ethernet/sfc/rx_common.c b/drivers/net/ethernet/sfc/rx_common.c index 68fc7d317693..d9d0a5805f1c 100644 --- a/drivers/net/ethernet/sfc/rx_common.c +++ b/drivers/net/ethernet/sfc/rx_common.c @@ -150,7 +150,10 @@ static void efx_init_rx_recycle_ring(struct efx_rx_queue *rx_queue) efx->rx_bufs_per_page); rx_queue->page_ring = kcalloc(page_ring_size, sizeof(*rx_queue->page_ring), GFP_KERNEL); - rx_queue->page_ptr_mask = page_ring_size - 1; + if (!rx_queue->page_ring) + rx_queue->page_ptr_mask = -1; + else + rx_queue->page_ptr_mask = page_ring_size - 1; } static void efx_fini_rx_recycle_ring(struct efx_rx_queue *rx_queue)
The return value of kcalloc() needs to be checked. To avoid dereference of null pointer in case of the failure of alloc, such as efx_fini_rx_recycle_ring(). Therefore, it should be better to change the definition of page_ptr_mask to signed int and then assign the page_ptr_mask to -1 when page_ring is NULL, in order to avoid the use in the loop. Fixes: 5a6681e22c14 ("sfc: separate out SFC4000 ("Falcon") support into new sfc-falcon driver") Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn> --- Changelog: v3 -> v4 *Change 1. Casade return -ENOMEM when alloc fails and deal with the error. *Change 2. Set size to -1 instead of return error. *Change 3. Change the Fixes tag. --- drivers/net/ethernet/sfc/net_driver.h | 2 +- drivers/net/ethernet/sfc/rx_common.c | 5 ++++- 2 files changed, 5 insertions(+), 2 deletions(-)