Commit 2bb90e5c authored Jul 19, 2019 by John Fastabend Committed by Daniel Borkmann Jul 22, 2019

bpf: sockmap, synchronize_rcu before free'ing map



We need to have a synchronize_rcu before free'ing the sockmap because
any outstanding psock references will have a pointer to the map and
when they use this could trigger a use after free.

Fixes: 604326b4 ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

parent 45a4521d

net/core/sock_map.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -247,6 +247,8 @@ static void sock_map_free(struct bpf_map *map)
		raw_spin_unlock_bh(&stab->lock);
		rcu_read_unlock();

		synchronize_rcu();

		bpf_map_area_free(stab->sks);
		kfree(stab);
		}

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