Merge branch 'wireguard-fixes'

Jason A. Donenfeld says:

====================
wireguard fixes for 5.7-rc7

Hopefully these are the last fixes for 5.7:

1) A trivial bump in the selftest harness to support gcc-10.
   build.wireguard.com is still on gcc-9 but I'll probably switch to
   gcc-10 in the coming weeks.

2) A concurrency fix regarding userspace modifying the pre-shared key at
   the same time as packets are being processed, reported by Matt
   Dunwoodie.

3) We were previously clearing skb->hash on egress, which broke
   fq_codel, cake, and other things that actually make use of the flow
   hash for queueing, reported by Dave Taht and Toke Høiland-Jørgensen.

4) A fix for the increased memory usage caused by (3). This can be
   thought of as part of patch (3), but because of the separate
   reasoning and breadth of it I thought made it a bit cleaner to put in
   a standalone commit.

Fixes (2), (3), and (4) are -stable material.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/net/wireguard/queueing.h b/drivers/net/wireguard/queueing.h
index 3432232..c58df43 100644
--- a/drivers/net/wireguard/queueing.h
+++ b/drivers/net/wireguard/queueing.h
@@ -87,12 +87,20 @@ static inline bool wg_check_packet_protocol(struct sk_buff *skb)
 	return real_protocol && skb->protocol == real_protocol;
 }
 
-static inline void wg_reset_packet(struct sk_buff *skb)
+static inline void wg_reset_packet(struct sk_buff *skb, bool encapsulating)
 {
+	u8 l4_hash = skb->l4_hash;
+	u8 sw_hash = skb->sw_hash;
+	u32 hash = skb->hash;
 	skb_scrub_packet(skb, true);
 	memset(&skb->headers_start, 0,
 	       offsetof(struct sk_buff, headers_end) -
 		       offsetof(struct sk_buff, headers_start));
+	if (encapsulating) {
+		skb->l4_hash = l4_hash;
+		skb->sw_hash = sw_hash;
+		skb->hash = hash;
+	}
 	skb->queue_mapping = 0;
 	skb->nohdr = 0;
 	skb->peeked = 0;