kernel/git/stable/linux.git/net/ipv6/esp6.c, branch master

net: Use helpers to get/set UDP len tree-wide

2026-07-22T11:47:02+00:00

Since BIG TCP for UDP tunnels will start using len=0 in the UDP header as an indicator of a GSO packet bigger than 65535 bytes, this commit introduces the following getter and setters to use tree-wide, in order to explicitly mark places where len=0 may be expected, and handle them properly: 1. udp_set_len() sets uh->len to its real value if it's not bigger than 65535, and to 0 otherwise: to be used in GSO context with aggregated packets. 2. udp_set_len_short() is to be used when the length is known to fit 16 bits. It WARNs when the caller tries to assign a bigger value if CONFIG_DEBUG_NET=y. 3. udp_get_len_short() returns len in host byte order: to be used on the RX side to deal with non-aggregated packets, or to access the raw value of the len field. 4. udp_get_len() decodes uh->len set by udp_set_len(). It checks whether the packet is GSO to guard from malformed packets. At the moment udp_set_len() is not used, a following commit will start using it after enabling len>65535 for GSO. Raw uh->len (in network byte order) is still accessed in a few places for checksum calculation purposes, and to decode len=0 in udpv6_rcv for jumbograms. udp_rcv and udpv6_rcv will be addressed by the commit that starts using udp_set_len() to set UDP len=0 for BIG TCP packets in UDP tunnels. Signed-off-by: Alice Mikityanska Reviewed-by: Willem de Bruijn Acked-by: Jason A. Donenfeld Link: https://patch.msgid.link/20260710134242.216538-2-alice.kernel@fastmail.im Reviewed-by: Nikolay Aleksandrov Signed-off-by: Paolo Abeni

esp: fix page frag reference leak on skb_to_sgvec failure

2026-06-09T13:58:17+00:00

In esp_output_tail(), when esp->inplace is false, the old skb page frags are replaced with a new page from the xfrm page_frag cache The source scatterlist (sg) is built from the old frags before the replacement, and esp_ssg_unref() is responsible for releasing the old page references after the crypto operation completes However, if the second skb_to_sgvec() call (which builds the destination scatterlist from the new page) fails, the code jumps to error_free which only calls kfree(tmp). The old page frag references captured in the source scatterlist are never released: 1 sg[] is built from old frags via skb_to_sgvec() (no extra get_page) 2 nr_frags is set to 1 and frag[0] is replaced with the new page 3 Second skb_to_sgvec() fails -> goto error_free Fix this by adding a bool parameter to esp_ssg_unref() that, when true, unconditionally unrefs the source scatterlist frags. Since req->src is not yet initialized by aead_request_set_crypt() at the point of the error, the source scatterlist is obtained directly via esp_req_sg() Existing callers pass false to preserve the original behavior The same issue exists in both esp4 and esp6 as the code is identical Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible") Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible") Signed-off-by: Alessandro Schino <7991aleschino@gmail.com> Signed-off-by: Steffen Klassert

Revert "esp: fix page frag reference leak on skb_to_sgvec failure"

2026-05-29T08:23:25+00:00

This reverts commit 2982e599fff6faa21c8df147d96fc7af6c1a2f24. The patch does not fully fix the issue and the Author does not match the 'Signed-off-by:' tag, so revert it for now. Signed-off-by: Steffen Klassert

xfrm: esp: restore combined single-frag length gate

2026-05-22T07:20:26+00:00

The ESP out-of-place fast path appends the trailer in esp_output_head() before esp_output_tail() allocates the destination page frag. The head-side gate currently checks skb->data_len and tailen separately, but the tail code allocates a single destination frag from the combined post-trailer skb->data_len. Reject the page-frag fast path when the combined aligned length exceeds a page. Otherwise skb_page_frag_refill() may fall back to a single page while the destination sg still spans the combined skb->data_len. Restore this combined-length page gate for both IPv4 and IPv6. Fixes: 5bd8baab087d ("esp: limit skb_page_frag_refill use to a single page") Cc: stable@vger.kernel.org Signed-off-by: Lin Ma Signed-off-by: Chenyuan Mi Signed-off-by: Jingguo Tan Reviewed-by: Sabrina Dubroca Signed-off-by: Steffen Klassert

esp: fix page frag reference leak on skb_to_sgvec failure

2026-05-22T07:19:37+00:00

In esp_output_tail(), when esp->inplace is false, the old skb page frags are replaced with a new page from the xfrm page_frag cache. The source scatterlist (sg) is built from the old frags before the replacement, and esp_ssg_unref() is responsible for releasing the old page references after the crypto operation completes. However, if the second skb_to_sgvec() call (which builds the destination scatterlist from the new page) fails, the code jumps to error_free which only calls kfree(tmp). The old page frag references captured in the source scatterlist are never released: 1. sg[] is built from old frags via skb_to_sgvec() (no extra get_page) 2. nr_frags is set to 1 and frag[0] is replaced with the new page 3. Second skb_to_sgvec() fails -> goto error_free 4. kfree(tmp) frees the sg[] memory but old frags are not unref'd 5. kfree_skb() only releases frag[0] (the new page), not the old ones Fix this by adding a bool parameter to esp_ssg_unref() that, when true, unconditionally unrefs the source scatterlist frags without checking req->src and req->dst, since those fields are not yet initialized by aead_request_set_crypt() at the point of the error. Existing callers pass false to preserve the original behavior. The same issue exists in both esp4 and esp6 as the code is identical. Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible") Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible") Signed-off-by: Alessandro Schino <7991aleschino@gmail.com> Signed-off-by: Steffen Klassert

xfrm: esp: avoid in-place decrypt on shared skb frags

2026-05-05T04:38:30+00:00

MSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP marks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(), so later paths that may modify packet data can first make a private copy. The IPv4/IPv6 datagram append paths did not set this flag when splicing pages into UDP skbs. That leaves an ESP-in-UDP packet made from shared pipe pages looking like an ordinary uncloned nonlinear skb. ESP input then takes the no-COW fast path for uncloned skbs without a frag_list and decrypts in place over data that is not owned privately by the skb. Mark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching TCP. Also make ESP input fall back to skb_cow_data() when the flag is present, so ESP does not decrypt externally backed frags in place. Private nonlinear skb frags still use the existing fast path. This intentionally does not change ESP output. In esp_output_head(), the path that appends the ESP trailer to existing skb tailroom without calling skb_cow_data() is not reachable for nonlinear skbs: skb_tailroom() returns zero when skb->data_len is nonzero, while ESP tailen is positive. Thus ESP output will either use the separate destination-frag path or fall back to skb_cow_data(). Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible") Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible") Fixes: 7da0dde68486 ("ip, udp: Support MSG_SPLICE_PAGES") Fixes: 6d8192bd69bb ("ip6, udp6: Support MSG_SPLICE_PAGES") Reported-by: Hyunwoo Kim Reported-by: Kuan-Ting Chen Tested-by: Hyunwoo Kim Cc: stable@vger.kernel.org Signed-off-by: Kuan-Ting Chen Signed-off-by: Steffen Klassert

esp: fix skb leak with espintcp and async crypto

2026-02-25T08:11:40+00:00

When the TX queue for espintcp is full, esp_output_tail_tcp will return an error and not free the skb, because with synchronous crypto, the common xfrm output code will drop the packet for us. With async crypto (esp_output_done), we need to drop the skb when esp_output_tail_tcp returns an error. Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Signed-off-by: Sabrina Dubroca Reviewed-by: Simon Horman Signed-off-by: Steffen Klassert

tcp: Don't pass hashinfo to socket lookup helpers.

2025-08-26T00:53:35+00:00

These socket lookup functions required struct inet_hashinfo because they are shared by TCP and DCCP. * __inet_lookup_established() * __inet_lookup_listener() * __inet6_lookup_established() * inet6_lookup_listener() DCCP has gone, and we don't need to pass hashinfo down to them. Let's fetch net->ipv4.tcp_death_row.hashinfo directly in the above 4 functions. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20250822190803.540788-5-kuniyu@google.com Signed-off-by: Jakub Kicinski

espintcp: remove encap socket caching to avoid reference leak

2025-04-14T09:59:17+00:00

The current scheme for caching the encap socket can lead to reference leaks when we try to delete the netns. The reference chain is: xfrm_state -> enacp_sk -> netns Since the encap socket is a userspace socket, it holds a reference on the netns. If we delete the espintcp state (through flush or individual delete) before removing the netns, the reference on the socket is dropped and the netns is correctly deleted. Otherwise, the netns may not be reachable anymore (if all processes within the ns have terminated), so we cannot delete the xfrm state to drop its reference on the socket. This patch results in a small (~2% in my tests) performance regression. A GC-type mechanism could be added for the socket cache, to clear references if the state hasn't been used "recently", but it's a lot more complex than just not caching the socket. Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Signed-off-by: Sabrina Dubroca Reviewed-by: Simon Horman Signed-off-by: Steffen Klassert

espintcp: fix skb leaks

2025-04-14T09:58:50+00:00

A few error paths are missing a kfree_skb. Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Signed-off-by: Sabrina Dubroca Reviewed-by: Simon Horman Signed-off-by: Steffen Klassert