From 220d89df1da6ed95ac74883a72a5fb43abf2a586 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 12 Jan 2026 17:26:21 +0000 Subject: [PATCH] net: add skb->data_len and (skb>end - skb->tail) to skb_dump() While working on a syzbot report, I found that skb_dump() is lacking two important parts : - skb->data_len. - (skb>end - skb->tail) tailroom is zero if skb is not linear. Signed-off-by: Eric Dumazet Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260112172621.4188700-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- net/core/skbuff.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index a56133902c0d..61746c2b95f6 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1312,14 +1312,15 @@ void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt) has_mac = skb_mac_header_was_set(skb); has_trans = skb_transport_header_was_set(skb); - printk("%sskb len=%u headroom=%u headlen=%u tailroom=%u\n" - "mac=(%d,%d) mac_len=%u net=(%d,%d) trans=%d\n" + printk("%sskb len=%u data_len=%u headroom=%u headlen=%u tailroom=%u\n" + "end-tail=%u mac=(%d,%d) mac_len=%u net=(%d,%d) trans=%d\n" "shinfo(txflags=%u nr_frags=%u gso(size=%hu type=%u segs=%hu))\n" "csum(0x%x start=%u offset=%u ip_summed=%u complete_sw=%u valid=%u level=%u)\n" "hash(0x%x sw=%u l4=%u) proto=0x%04x pkttype=%u iif=%d\n" "priority=0x%x mark=0x%x alloc_cpu=%u vlan_all=0x%x\n" "encapsulation=%d inner(proto=0x%04x, mac=%u, net=%u, trans=%u)\n", - level, skb->len, headroom, skb_headlen(skb), tailroom, + level, skb->len, skb->data_len, headroom, skb_headlen(skb), + tailroom, skb->end - skb->tail, has_mac ? skb->mac_header : -1, has_mac ? skb_mac_header_len(skb) : -1, skb->mac_len, -- 2.47.3