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/crypto/poly1305.h | 67 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 include/crypto/poly1305.h (limited to 'include/crypto/poly1305.h') diff --git a/include/crypto/poly1305.h b/include/crypto/poly1305.h new file mode 100644 index 000000000..190beb427 --- /dev/null +++ b/include/crypto/poly1305.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Common values for the Poly1305 algorithm + */ + +#ifndef _CRYPTO_POLY1305_H +#define _CRYPTO_POLY1305_H + +#include + +#define POLY1305_BLOCK_SIZE 16 +#define POLY1305_KEY_SIZE 32 +#define POLY1305_DIGEST_SIZE 16 + +/* The poly1305_key and poly1305_state types are mostly opaque and + * implementation-defined. Limbs might be in base 2^64 or base 2^26, or + * different yet. The union type provided keeps these 64-bit aligned for the + * case in which this is implemented using 64x64 multiplies. + */ + +struct poly1305_key { + union { + u32 r[5]; + u64 r64[3]; + }; +}; + +struct poly1305_core_key { + struct poly1305_key key; + struct poly1305_key precomputed_s; +}; + +struct poly1305_state { + union { + u32 h[5]; + u64 h64[3]; + }; +}; + +/* Combined state for block function. */ +struct poly1305_block_state { + /* accumulator */ + struct poly1305_state h; + /* key */ + union { + struct poly1305_key opaque_r[CONFIG_CRYPTO_LIB_POLY1305_RSIZE]; + struct poly1305_core_key core_r; + }; +}; + +struct poly1305_desc_ctx { + /* partial buffer */ + u8 buf[POLY1305_BLOCK_SIZE]; + /* bytes used in partial buffer */ + unsigned int buflen; + /* finalize key */ + u32 s[4]; + struct poly1305_block_state state; +}; + +void poly1305_init(struct poly1305_desc_ctx *desc, + const u8 key[at_least POLY1305_KEY_SIZE]); +void poly1305_update(struct poly1305_desc_ctx *desc, + const u8 *src, unsigned int nbytes); +void poly1305_final(struct poly1305_desc_ctx *desc, u8 *digest); + +#endif -- cgit v1.3.1