skb: Do mix page pool and page referenced frags in GRO

[ Upstream commit 7d2c89b325874a35564db5630a459966afab04cc ]

GSO should not merge page pool recycled frames with standard reference
counted frames. Traditionally this didn't occur, at least not often.
However as we start looking at adding support for wireless adapters there
becomes the potential to mix the two due to A-MSDU repartitioning frames in
the receive path. There are possibly other places where this may have
occurred however I suspect they must be few and far between as we have not
seen this issue until now.

Fixes: 2c6f2cc5b8f3 ("page_pool: add frag page recycling support in page pool")
Reported-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/167475990764.1934330.11960904198087757911.stgit@localhost.localdomain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/core/gro.c b/net/core/gro.c
index 1b4abfb9a7a13675603b7d52c15c9ecf6b6a2d1f..352f966cb1dac0607d96c111d1553fb46c5d3c65 100644 (file)
--- a/net/core/gro.c
+++ b/net/core/gro.c
@@ -162,6 +162,15 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb)
        struct sk_buff *lp;
        int segs;
 
+       /* Do not splice page pool based packets w/ non-page pool
+        * packets. This can result in reference count issues as page
+        * pool pages will not decrement the reference count and will
+        * instead be immediately returned to the pool or have frag
+        * count decremented.
+        */
+       if (p->pp_recycle != skb->pp_recycle)
+               return -ETOOMANYREFS;
+
        /* pairs with WRITE_ONCE() in netif_set_gro_max_size() */
        gro_max_size = READ_ONCE(p->dev->gro_max_size);