4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <eduma...@google.com>
[ Upstream commit e048fc50d7bde23136e098e04a324d7e3404408d ]
A driver using dev_alloc_page() must not reuse a page allocated from
emergency memory reserve.
Otherwise all packets using this page will be immediately dropped,
unless for very specific sockets having SOCK_MEMALLOC bit set.
This issue might be hard to debug, because only a fraction of received
packets would be dropped.
Fixes: 4415a0319f92 ("net/mlx5e: Implement RX mapped page cache for page
recycle")
Signed-off-by: Eric Dumazet <eduma...@google.com>
Cc: Tariq Toukan <tar...@mellanox.com>
Cc: Saeed Mahameed <sae...@mellanox.com>
Acked-by: Saeed Mahameed <sae...@mellanox.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 3 +++
1 file changed, 3 insertions(+)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -193,6 +193,9 @@ static inline bool mlx5e_rx_cache_put(st
return false;
}
+ if (unlikely(page_is_pfmemalloc(dma_info->page)))
+ return false;
+
cache->page_cache[cache->tail] = *dma_info;
cache->tail = tail_next;
return true;
