diff mbox series

[5.4,188/320] bpf: Do not WARN in bpf_warn_invalid_xdp_action()

Message ID 20220124184000.041545255@linuxfoundation.org
State Superseded
Headers show
Series None | expand

Commit Message

Greg KH Jan. 24, 2022, 6:42 p.m. UTC 
From: Paolo Abeni <pabeni@redhat.com>

[ 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@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/016ceec56e4817ebb2a9e35ce794d5c917df572c.1638189075.git.pabeni@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/core/filter.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/net/core/filter.c b/net/core/filter.c
index b90c0b5a10112..92ce4d46f02e4 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6912,9 +6912,9 @@  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);