From: Jason A. Donenfeld Date: Thu, 14 Mar 2024 22:49:10 +0000 (-0600) Subject: wireguard: netlink: access device through ctx instead of peer X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=71cbd32e3db82ea4a74e3ef9aeeaa6971969c86f;p=linux.git wireguard: netlink: access device through ctx instead of peer The previous commit fixed a bug that led to a NULL peer->device being dereferenced. It's actually easier and faster performance-wise to instead get the device from ctx->wg. This semantically makes more sense too, since ctx->wg->peer_allowedips.seq is compared with ctx->allowedips_seq, basing them both in ctx. This also acts as a defence in depth provision against freed peers. Cc: stable@vger.kernel.org Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Signed-off-by: Jason A. Donenfeld Reviewed-by: Jiri Pirko Signed-off-by: Paolo Abeni --- diff --git a/drivers/net/wireguard/netlink.c b/drivers/net/wireguard/netlink.c index c17aee454fa3b..f7055180ba4aa 100644 --- a/drivers/net/wireguard/netlink.c +++ b/drivers/net/wireguard/netlink.c @@ -164,8 +164,8 @@ get_peer(struct wg_peer *peer, struct sk_buff *skb, struct dump_ctx *ctx) if (!allowedips_node) goto no_allowedips; if (!ctx->allowedips_seq) - ctx->allowedips_seq = peer->device->peer_allowedips.seq; - else if (ctx->allowedips_seq != peer->device->peer_allowedips.seq) + ctx->allowedips_seq = ctx->wg->peer_allowedips.seq; + else if (ctx->allowedips_seq != ctx->wg->peer_allowedips.seq) goto no_allowedips; allowedips_nest = nla_nest_start(skb, WGPEER_A_ALLOWEDIPS);