From 5f4e51abfbe6eb444fa91906a5cd083044278297 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Tue, 5 Mar 2024 22:31:32 +0100 Subject: [PATCH] cpumap: Zero-initialise xdp_rxq_info struct before running XDP program MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 2487007aa3b9fafbd2cb14068f49791ce1d7ede5 ] When running an XDP program that is attached to a cpumap entry, we don't initialise the xdp_rxq_info data structure being used in the xdp_buff that backs the XDP program invocation. Tobias noticed that this leads to random values being returned as the xdp_md->rx_queue_index value for XDP programs running in a cpumap. This means we're basically returning the contents of the uninitialised memory, which is bad. Fix this by zero-initialising the rxq data structure before running the XDP program. Fixes: 9216477449f3 ("bpf: cpumap: Add the possibility to attach an eBPF program to cpumap") Reported-by: Tobias Böhm Signed-off-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/r/20240305213132.11955-1-toke@redhat.com Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin --- kernel/bpf/cpumap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index c61a23b564aa..2dcc04b2f330 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -229,7 +229,7 @@ static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu, void **frames, int n, struct xdp_cpumap_stats *stats) { - struct xdp_rxq_info rxq; + struct xdp_rxq_info rxq = {}; struct xdp_buff xdp; int i, nframes = 0;