From aa54b1d27fe0c2b78e664a34fd0fdf7cd1960d71 Mon Sep 17 00:00:00 2001 From: Hyunwoo Kim Date: Fri, 8 May 2026 17:53:09 +0900 Subject: [PATCH] rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present The DATA-packet handler in rxrpc_input_call_event() and the RESPONSE handler in rxrpc_verify_response() copy the skb to a linear one before calling into the security ops only when skb_cloned() is true. An skb that is not cloned but still carries externally-owned paged fragments (e.g. SKBFL_SHARED_FRAG set by splice() into a UDP socket via __ip_append_data, or a chained skb_has_frag_list()) falls through to the in-place decryption path, which binds the frag pages directly into the AEAD/skcipher SGL via skb_to_sgvec(). Extend the gate to also unshare when skb_has_frag_list() or skb_has_shared_frag() is true. This catches the splice-loopback vector and other externally-shared frag sources while preserving the zero-copy fast path for skbs whose frags are kernel-private (e.g. NIC page_pool RX, GRO). The OOM/trace handling already in place is reused. Fixes: d0d5c0cd1e71 ("rxrpc: Use skb_unshare() rather than skb_cow_data()") Cc: stable@vger.kernel.org Signed-off-by: Hyunwoo Kim Reviewed-by: Jiayuan Chen Acked-by: David Howells Signed-off-by: Linus Torvalds --- net/rxrpc/call_event.c | 4 +++- net/rxrpc/conn_event.c | 3 ++- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c index fdd683261226..2b19b252225e 100644 --- a/net/rxrpc/call_event.c +++ b/net/rxrpc/call_event.c @@ -334,7 +334,9 @@ bool rxrpc_input_call_event(struct rxrpc_call *call) if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA && sp->hdr.securityIndex != 0 && - skb_cloned(skb)) { + (skb_cloned(skb) || + skb_has_frag_list(skb) || + skb_has_shared_frag(skb))) { /* Unshare the packet so that it can be * modified by in-place decryption. */ diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c index a2130d25aaa9..442414d90ba1 100644 --- a/net/rxrpc/conn_event.c +++ b/net/rxrpc/conn_event.c @@ -245,7 +245,8 @@ static int rxrpc_verify_response(struct rxrpc_connection *conn, { int ret; - if (skb_cloned(skb)) { + if (skb_cloned(skb) || skb_has_frag_list(skb) || + skb_has_shared_frag(skb)) { /* Copy the packet if shared so that we can do in-place * decryption. */