diff options
| author | Eric Dumazet <edumazet@google.com> | 2025-10-15 05:27:15 +0000 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2025-10-16 16:03:07 +0200 |
| commit | 6de1dec1c166c7f7324ce52ccfdf43e2fa743b19 (patch) | |
| tree | 103845138cff576468f824f636bf2b0e5e32c1cc | |
| parent | 8d93ff40d49d70e05c82a74beae31f883fe0eaf8 (diff) | |
udp: do not use skb_release_head_state() before skb_attempt_defer_free()
Michal reported and bisected an issue after recent adoption
of skb_attempt_defer_free() in UDP.
The issue here is that skb_release_head_state() is called twice per skb,
one time from skb_consume_udp(), then a second time from skb_defer_free_flush()
and napi_consume_skb().
As Sabrina suggested, remove skb_release_head_state() call from
skb_consume_udp().
Add a DEBUG_NET_WARN_ON_ONCE(skb_nfct(skb)) in skb_attempt_defer_free()
Many thanks to Michal, Sabrina, Paolo and Florian for their help.
Fixes: 6471658dc66c ("udp: use skb_attempt_defer_free()")
Reported-and-bisected-by: Michal Kubecek <mkubecek@suse.cz>
Closes: https://lore.kernel.org/netdev/gpjh4lrotyephiqpuldtxxizrsg6job7cvhiqrw72saz2ubs3h@g6fgbvexgl3r/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Michal Kubecek <mkubecek@suse.cz>
Cc: Sabrina Dubroca <sd@queasysnail.net>
Cc: Florian Westphal <fw@strlen.de>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/20251015052715.4140493-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rw-r--r-- | net/core/skbuff.c | 1 | ||||
| -rw-r--r-- | net/ipv4/udp.c | 2 |
2 files changed, 1 insertions, 2 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index bc12790017b0..6be01454f262 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -7200,6 +7200,7 @@ nodefer: kfree_skb_napi_cache(skb); DEBUG_NET_WARN_ON_ONCE(skb_dst(skb)); DEBUG_NET_WARN_ON_ONCE(skb->destructor); + DEBUG_NET_WARN_ON_ONCE(skb_nfct(skb)); sdn = per_cpu_ptr(net_hotdata.skb_defer_nodes, cpu) + numa_node_id(); diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 95241093b7f0..30dfbf73729d 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1851,8 +1851,6 @@ void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len) sk_peek_offset_bwd(sk, len); if (!skb_shared(skb)) { - if (unlikely(udp_skb_has_head_state(skb))) - skb_release_head_state(skb); skb_attempt_defer_free(skb); return; } |