From 7717fbb14028be5735acb911aeb7553b7c662418 Mon Sep 17 00:00:00 2001 From: Eric Woudstra Date: Tue, 24 Feb 2026 16:50:30 +0100 Subject: net: pppoe: avoid zero-length arrays in struct pppoe_hdr Jakub Kicinski reported following issue in upcoming patches: W=1 C=1 GCC build gives us: net/bridge/netfilter/nf_conntrack_bridge.c: note: in included file (through ../include/linux/if_pppox.h, ../include/uapi/linux/netfilter_bridge.h, ../include/linux/netfilter_bridge.h): include/uapi/linux/if_pppox.h: 153:29: warning: array of flexible structures sparse doesn't like that hdr has a zero-length array which overlaps proto. The kernel code doesn't currently need those arrays. PPPoE connection is functional after applying this patch. Reviewed-by: Nikolay Aleksandrov Reviewed-by: Kees Cook Signed-off-by: Eric Woudstra Link: https://patch.msgid.link/20260224155030.106918-1-ericwouds@gmail.com Signed-off-by: Jakub Kicinski --- include/uapi/linux/if_pppox.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/if_pppox.h b/include/uapi/linux/if_pppox.h index 9abd80dcc46f..29b804aa7474 100644 --- a/include/uapi/linux/if_pppox.h +++ b/include/uapi/linux/if_pppox.h @@ -122,7 +122,9 @@ struct sockaddr_pppol2tpv3in6 { struct pppoe_tag { __be16 tag_type; __be16 tag_len; +#ifndef __KERNEL__ char tag_data[]; +#endif } __attribute__ ((packed)); /* Tag identifiers */ @@ -150,7 +152,9 @@ struct pppoe_hdr { __u8 code; __be16 sid; __be16 length; +#ifndef __KERNEL__ struct pppoe_tag tag[]; +#endif } __packed; /* Length of entire PPPoE + PPP header */ -- cgit v1.2.3