6.6-stable review patch. If anyone has any objections, please let me know.
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From: Sebastian Andrzej Siewior bigeasy@linutronix.de
[ Upstream commit 2127c604383666675789fd4a5fc2aead46c73aad ]
xsk_build_skb() allocates a page and adds it to the skb via skb_add_rx_frag() and specifies 0 for truesize. This leads to a warning in skb_add_rx_frag() with CONFIG_DEBUG_NET enabled because size is larger than truesize.
Increasing truesize requires to add the same amount to socket's sk_wmem_alloc counter in order not to underflow the counter during release in the destructor (sock_wfree()).
Pass the size of the allocated page as truesize to skb_add_rx_frag(). Add this mount to socket's sk_wmem_alloc counter.
Fixes: cf24f5a5feea ("xsk: add support for AF_XDP multi-buffer on Tx path") Signed-off-by: Sebastian Andrzej Siewior bigeasy@linutronix.de Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Maciej Fijalkowski maciej.fijalkowski@intel.com Link: https://lore.kernel.org/bpf/20240202163221.2488589-1-bigeasy@linutronix.de Signed-off-by: Sasha Levin sashal@kernel.org --- net/xdp/xsk.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index d849dc04a3343..2c3ba42bfcdcb 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -683,7 +683,8 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, memcpy(vaddr, buffer, len); kunmap_local(vaddr);
- skb_add_rx_frag(skb, nr_frags, page, 0, len, 0); + skb_add_rx_frag(skb, nr_frags, page, 0, len, PAGE_SIZE); + refcount_add(PAGE_SIZE, &xs->sk.sk_wmem_alloc); } }