[PATCH 5.19 113/207] iavf: Fix bad page state

Greg Kroah-Hartman
2022-09-26T11:52:28Z

From: Norbert Zulinski <norbertx.zulinski@intel.com>

[ Upstream commit 66039eb9015eee4f7ff0c99b83c65c7ecb3c8190 ]

Fix bad page state, free inappropriate page in handling dummy
descriptor. iavf_build_skb now has to check not only if rx_buffer is
NULL but also if size is zero, same thing in iavf_clean_rx_irq.
Without this patch driver would free page that will be used
by napi_build_skb.

Fixes: a9f49e006030 ("iavf: Fix handling of dummy receive descriptors")
Signed-off-by: Norbert Zulinski <norbertx.zulinski@intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/intel/iavf/iavf_txrx.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/iavf/iavf_txrx.c b/drivers/net/ethernet/intel/iavf/iavf_txrx.c
index 4c3f3f419110..18b6a702a1d6 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_txrx.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_txrx.c
@@ -1393,7 +1393,7 @@ static struct sk_buff *iavf_build_skb(struct iavf_ring *rx_ring,
#endif
struct sk_buff *skb;

- if (!rx_buffer)
+ if (!rx_buffer || !size)
return NULL;
/* prefetch first cache line of first page */
va = page_address(rx_buffer->page) + rx_buffer->page_offset;
@@ -1551,7 +1551,7 @@ static int iavf_clean_rx_irq(struct iavf_ring *rx_ring, int budget)
/* exit if we failed to retrieve a buffer */
if (!skb) {
rx_ring->rx_stats.alloc_buff_failed++;
- if (rx_buffer)
+ if (rx_buffer && size)
rx_buffer->pagecnt_bias++;
break;
}
--
2.35.1