4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 3bed3cc4156eedf652b4df72bdb35d4f1a2a739d ]
This patch addresses the fact that there are drivers, specifically tun, that will call into the network page fragment allocators with buffer sizes that are not cache aligned. Doing this could result in data alignment and DMA performance issues as these fragment pools are also shared with the skb allocator and any other devices that will use napi_alloc_frags or netdev_alloc_frags.
Fixes: ffde7328a36d ("net: Split netdev_alloc_frag into __alloc_page_frag and add __napi_alloc_frag") Reported-by: Jann Horn jannh@google.com Signed-off-by: Alexander Duyck alexander.h.duyck@linux.intel.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/skbuff.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index eebc3106d30ef..fc3d652a2de0c 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -353,6 +353,8 @@ static void *__netdev_alloc_frag(unsigned int fragsz, gfp_t gfp_mask) */ void *netdev_alloc_frag(unsigned int fragsz) { + fragsz = SKB_DATA_ALIGN(fragsz); + return __netdev_alloc_frag(fragsz, GFP_ATOMIC); } EXPORT_SYMBOL(netdev_alloc_frag); @@ -366,6 +368,8 @@ static void *__napi_alloc_frag(unsigned int fragsz, gfp_t gfp_mask)
void *napi_alloc_frag(unsigned int fragsz) { + fragsz = SKB_DATA_ALIGN(fragsz); + return __napi_alloc_frag(fragsz, GFP_ATOMIC); } EXPORT_SYMBOL(napi_alloc_frag);