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/internal/simd.h | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 include/crypto/internal/simd.h (limited to 'include/crypto/internal/simd.h') diff --git a/include/crypto/internal/simd.h b/include/crypto/internal/simd.h new file mode 100644 index 000000000..f5e5d7b63 --- /dev/null +++ b/include/crypto/internal/simd.h @@ -0,0 +1,40 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Shared crypto simd helpers + */ + +#ifndef _CRYPTO_INTERNAL_SIMD_H +#define _CRYPTO_INTERNAL_SIMD_H + +#include +#include +#include + +struct simd_aead_alg; +struct aead_alg; + +int simd_register_aeads_compat(struct aead_alg *algs, int count, + struct simd_aead_alg **simd_algs); + +void simd_unregister_aeads(struct aead_alg *algs, int count, + struct simd_aead_alg **simd_algs); + +/* + * crypto_simd_usable() - is it allowed at this time to use SIMD instructions or + * access the SIMD register file? + * + * This delegates to may_use_simd(), except that this also returns false if SIMD + * in crypto code has been temporarily disabled on this CPU by the crypto + * self-tests, in order to test the no-SIMD fallback code. This override is + * currently limited to configurations where the "full" self-tests are enabled, + * because it might be a bit too invasive to be part of the "fast" self-tests. + */ +#ifdef CONFIG_CRYPTO_SELFTESTS_FULL +DECLARE_PER_CPU(bool, crypto_simd_disabled_for_test); +#define crypto_simd_usable() \ + (may_use_simd() && !this_cpu_read(crypto_simd_disabled_for_test)) +#else +#define crypto_simd_usable() may_use_simd() +#endif + +#endif /* _CRYPTO_INTERNAL_SIMD_H */ -- cgit v1.3.1