6.6-stable review patch. If anyone has any objections, please let me know.
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From: Aleksandr Mishin amishin@t-argos.ru
[ Upstream commit eb592008f79be52ccef88cd9a5249b3fc0367278 ]
build_skb() returns NULL in case of a memory allocation failure so handle it inside __octep_oq_process_rx() to avoid NULL pointer dereference.
__octep_oq_process_rx() is called during NAPI polling by the driver. If skb allocation fails, keep on pulling packets out of the Rx DMA queue: we shouldn't break the polling immediately and thus falsely indicate to the octep_napi_poll() that the Rx pressure is going down. As there is no associated skb in this case, don't process the packets and don't push them up the network stack - they are skipped.
Helper function is implemented to unmmap/flush all the fragment buffers used by the dropped packet. 'alloc_failures' counter is incremented to mark the skb allocation error in driver statistics.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 37d79d059606 ("octeon_ep: add Tx/Rx processing and interrupt support") Suggested-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Aleksandr Mishin amishin@t-argos.ru Reviewed-by: Jacob Keller jacob.e.keller@intel.com Signed-off-by: Andrew Lunn andrew@lunn.ch Signed-off-by: Sasha Levin sashal@kernel.org --- .../net/ethernet/marvell/octeon_ep/octep_rx.c | 27 +++++++++++++++++++ 1 file changed, 27 insertions(+)
diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c index cfbfad95b0211..c7f4e3c058b7f 100644 --- a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c +++ b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c @@ -360,6 +360,27 @@ static void octep_oq_next_pkt(struct octep_oq *oq, *read_idx = 0; }
+/** + * octep_oq_drop_rx() - Free the resources associated with a packet. + * + * @oq: Octeon Rx queue data structure. + * @buff_info: Current packet buffer info. + * @read_idx: Current packet index in the ring. + * @desc_used: Current packet descriptor number. + * + */ +static void octep_oq_drop_rx(struct octep_oq *oq, + struct octep_rx_buffer *buff_info, + u32 *read_idx, u32 *desc_used) +{ + int data_len = buff_info->len - oq->max_single_buffer_size; + + while (data_len > 0) { + octep_oq_next_pkt(oq, buff_info, read_idx, desc_used); + data_len -= oq->buffer_size; + }; +} + /** * __octep_oq_process_rx() - Process hardware Rx queue and push to stack. * @@ -415,6 +436,12 @@ static int __octep_oq_process_rx(struct octep_device *oct, octep_oq_next_pkt(oq, buff_info, &read_idx, &desc_used);
skb = build_skb((void *)resp_hw, PAGE_SIZE); + if (!skb) { + octep_oq_drop_rx(oq, buff_info, + &read_idx, &desc_used); + oq->stats.alloc_failures++; + continue; + } skb_reserve(skb, data_offset);
rx_bytes += buff_info->len;