diff mbox series

[net-next,v2,1/2] bpf: do not WARN in bpf_warn_invalid_xdp_action()

Message ID 1817b31eac5f1b10abb2870ff09ed6af4814ef01.1637924200.git.pabeni@redhat.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series bpf: do not WARN in bpf_warn_invalid_xdp_action() | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 27 this patch: 27
netdev/cc_maintainers warning 9 maintainers not CCed: kafai@fb.com songliubraving@fb.com john.fastabend@gmail.com hawk@kernel.org kuba@kernel.org davem@davemloft.net kpsingh@kernel.org yhs@fb.com andrii@kernel.org
netdev/build_clang success Errors and warnings before: 22 this patch: 22
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 31 this patch: 31
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 12 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Paolo Abeni Nov. 26, 2021, 11:19 a.m. UTC 
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 <toke@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
 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 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);