[PATCH v3 net-next 1/2] bpf: do not WARN in bpf_warn_invalid_xdp_action()
From: Paolo Abeni <pabeni@redhat.com>
Date: 2021-11-30 10:08:48
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
The WARN_ONCE() in bpf_warn_invalid_xdp_action() can be triggered by any bugged program, and even attaching a correct program to a NIC not supporting the given action. The resulting splat, beyond polluting the logs, fouls automated tools: e.g. a syzkaller reproducers using an XDP program returning an unsupported action will never pass validation. Replace the WARN_ONCE with a less intrusive pr_warn_once(). Acked-by: Toke Høiland-Jørgensen <redacted> Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- net/core/filter.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/core/filter.c b/net/core/filter.c
index 8271624a19aa..5631acf3f10c 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c@@ -8185,9 +8185,9 @@ void bpf_warn_invalid_xdp_action(u32 act) { const u32 act_max = XDP_REDIRECT; - WARN_ONCE(1, "%s XDP return value %u, expect packet loss!\n", - act > act_max ? "Illegal" : "Driver unsupported", - act); + pr_warn_once("%s XDP return value %u, expect packet loss!\n", + act > act_max ? "Illegal" : "Driver unsupported", + act); } EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action);
--
2.33.1