From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- include/net/sctp/auth.h | 110 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 include/net/sctp/auth.h (limited to 'include/net/sctp/auth.h') diff --git a/include/net/sctp/auth.h b/include/net/sctp/auth.h new file mode 100644 index 000000000..85efa65d3 --- /dev/null +++ b/include/net/sctp/auth.h @@ -0,0 +1,110 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* SCTP kernel implementation + * (C) Copyright 2007 Hewlett-Packard Development Company, L.P. + * + * This file is part of the SCTP kernel implementation + * + * Please send any bug reports or fixes you make to the + * email address(es): + * lksctp developers + * + * Written or modified by: + * Vlad Yasevich + */ + +#ifndef __sctp_auth_h__ +#define __sctp_auth_h__ + +#include +#include + +struct sctp_endpoint; +struct sctp_association; +struct sctp_authkey; +struct sctp_hmacalgo; +struct sctp_cookie; + +/* Defines an HMAC algorithm supported by SCTP chunk authentication */ +struct sctp_hmac { + __u16 hmac_id; /* one of SCTP_AUTH_HMAC_ID_* */ + __u16 hmac_len; /* length of the HMAC value in bytes */ +}; + +/* This is generic structure that containst authentication bytes used + * as keying material. It's a what is referred to as byte-vector all + * over SCTP-AUTH + */ +struct sctp_auth_bytes { + refcount_t refcnt; + __u32 len; + __u8 data[]; +}; + +/* Definition for a shared key, weather endpoint or association */ +struct sctp_shared_key { + struct list_head key_list; + struct sctp_auth_bytes *key; + refcount_t refcnt; + __u16 key_id; + __u8 deactivated; +}; + +#define key_for_each(__key, __list_head) \ + list_for_each_entry(__key, __list_head, key_list) + +#define key_for_each_safe(__key, __tmp, __list_head) \ + list_for_each_entry_safe(__key, __tmp, __list_head, key_list) + +static inline void sctp_auth_key_hold(struct sctp_auth_bytes *key) +{ + if (!key) + return; + + refcount_inc(&key->refcnt); +} + +void sctp_auth_key_put(struct sctp_auth_bytes *key); +struct sctp_shared_key *sctp_auth_shkey_create(__u16 key_id, gfp_t gfp); +void sctp_auth_destroy_keys(struct list_head *keys); +int sctp_auth_asoc_init_active_key(struct sctp_association *asoc, gfp_t gfp); +struct sctp_shared_key *sctp_auth_get_shkey( + const struct sctp_association *asoc, + __u16 key_id); +int sctp_auth_asoc_copy_shkeys(const struct sctp_endpoint *ep, + struct sctp_association *asoc, + gfp_t gfp); +bool sctp_auth_verify_cookie_params(const struct sctp_endpoint *ep, + const struct sctp_cookie *cookie); +const struct sctp_hmac *sctp_auth_get_hmac(__u16 hmac_id); +const struct sctp_hmac * +sctp_auth_asoc_get_hmac(const struct sctp_association *asoc); +void sctp_auth_asoc_set_default_hmac(struct sctp_association *asoc, + struct sctp_hmac_algo_param *hmacs); +int sctp_auth_asoc_verify_hmac_id(const struct sctp_association *asoc, + __be16 hmac_id); +int sctp_auth_send_cid(enum sctp_cid chunk, + const struct sctp_association *asoc); +int sctp_auth_recv_cid(enum sctp_cid chunk, + const struct sctp_association *asoc); +int sctp_auth_calculate_hmac(const struct sctp_association *asoc, + struct sk_buff *skb, struct sctp_auth_chunk *auth, + struct sctp_shared_key *ep_key, gfp_t gfp); +void sctp_auth_shkey_release(struct sctp_shared_key *sh_key); +void sctp_auth_shkey_hold(struct sctp_shared_key *sh_key); + +/* API Helpers */ +int sctp_auth_ep_add_chunkid(struct sctp_endpoint *ep, __u8 chunk_id); +int sctp_auth_ep_set_hmacs(struct sctp_endpoint *ep, + struct sctp_hmacalgo *hmacs); +int sctp_auth_set_key(struct sctp_endpoint *ep, struct sctp_association *asoc, + struct sctp_authkey *auth_key); +int sctp_auth_set_active_key(struct sctp_endpoint *ep, + struct sctp_association *asoc, __u16 key_id); +int sctp_auth_del_key_id(struct sctp_endpoint *ep, + struct sctp_association *asoc, __u16 key_id); +int sctp_auth_deact_key_id(struct sctp_endpoint *ep, + struct sctp_association *asoc, __u16 key_id); +int sctp_auth_init(struct sctp_endpoint *ep, gfp_t gfp); +void sctp_auth_free(struct sctp_endpoint *ep); + +#endif -- cgit v1.3.1