From: Paolo Abeni <pabeni@xxxxxxxxxx> [ Upstream commit 2cbad989033bff0256675c38f96f5faab852af4b ] 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(). Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx> Link: https://lore.kernel.org/bpf/016ceec56e4817ebb2a9e35ce794d5c917df572c.1638189075.git.pabeni@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 01496c7cb42d7..7d68c98a00aa8 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5534,9 +5534,9 @@ 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); -- 2.34.1
