diff options
| author | Magnus Karlsson <magnus.karlsson@intel.com> | 2019-10-21 10:16:58 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2019-10-23 20:22:11 -0700 |
| commit | 2afd23f78f39da84937006ecd24aa664a4ab052b (patch) | |
| tree | 3c042b80af88bd4aa97fd25a7069935153817be4 | |
| parent | 3b4d9eb2ee74dd5ea7fa36cffb0ca7f5bc4924da (diff) | |
xsk: Fix registration of Rx-only sockets
Having Rx-only AF_XDP sockets can potentially lead to a crash in the
system by a NULL pointer dereference in xsk_umem_consume_tx(). This
function iterates through a list of all sockets tied to a umem and
checks if there are any packets to send on the Tx ring. Rx-only
sockets do not have a Tx ring, so this will cause a NULL pointer
dereference. This will happen if you have registered one or more
Rx-only sockets to a umem and the driver is checking the Tx ring even
on Rx, or if the XDP_SHARED_UMEM mode is used and there is a mix of
Rx-only and other sockets tied to the same umem.
Fixed by only putting sockets with a Tx component on the list that
xsk_umem_consume_tx() iterates over.
Fixes: ac98d8aab61b ("xsk: wire upp Tx zero-copy functions")
Reported-by: Kal Cutter Conley <kal.conley@dectris.com>
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/bpf/1571645818-16244-1-git-send-email-magnus.karlsson@intel.com
| -rw-r--r-- | net/xdp/xdp_umem.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index 16d5f353163a..3049af269fbf 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -27,6 +27,9 @@ void xdp_add_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs) { unsigned long flags; + if (!xs->tx) + return; + spin_lock_irqsave(&umem->xsk_list_lock, flags); list_add_rcu(&xs->list, &umem->xsk_list); spin_unlock_irqrestore(&umem->xsk_list_lock, flags); @@ -36,6 +39,9 @@ void xdp_del_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs) { unsigned long flags; + if (!xs->tx) + return; + spin_lock_irqsave(&umem->xsk_list_lock, flags); list_del_rcu(&xs->list); spin_unlock_irqrestore(&umem->xsk_list_lock, flags); |