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/des.h | 127 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) create mode 100644 include/crypto/internal/des.h (limited to 'include/crypto/internal/des.h') diff --git a/include/crypto/internal/des.h b/include/crypto/internal/des.h new file mode 100644 index 000000000..723fe5bf1 --- /dev/null +++ b/include/crypto/internal/des.h @@ -0,0 +1,127 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * DES & Triple DES EDE key verification helpers + */ + +#ifndef __CRYPTO_INTERNAL_DES_H +#define __CRYPTO_INTERNAL_DES_H + +#include +#include +#include +#include +#include + +/** + * crypto_des_verify_key - Check whether a DES key is weak + * @tfm: the crypto algo + * @key: the key buffer + * + * Returns -EINVAL if the key is weak and the crypto TFM does not permit weak + * keys. Otherwise, 0 is returned. + * + * It is the job of the caller to ensure that the size of the key equals + * DES_KEY_SIZE. + */ +static inline int crypto_des_verify_key(struct crypto_tfm *tfm, const u8 *key) +{ + struct des_ctx tmp; + int err; + + err = des_expand_key(&tmp, key, DES_KEY_SIZE); + if (err == -ENOKEY) { + if (crypto_tfm_get_flags(tfm) & CRYPTO_TFM_REQ_FORBID_WEAK_KEYS) + err = -EINVAL; + else + err = 0; + } + memzero_explicit(&tmp, sizeof(tmp)); + return err; +} + +/* + * RFC2451: + * + * For DES-EDE3, there is no known need to reject weak or + * complementation keys. Any weakness is obviated by the use of + * multiple keys. + * + * However, if the first two or last two independent 64-bit keys are + * equal (k1 == k2 or k2 == k3), then the DES3 operation is simply the + * same as DES. Implementers MUST reject keys that exhibit this + * property. + * + */ +static inline int des3_ede_verify_key(const u8 *key, unsigned int key_len, + bool check_weak) +{ + int ret = fips_enabled ? -EINVAL : -ENOKEY; + u32 K[6]; + + memcpy(K, key, DES3_EDE_KEY_SIZE); + + if ((!((K[0] ^ K[2]) | (K[1] ^ K[3])) || + !((K[2] ^ K[4]) | (K[3] ^ K[5]))) && + (fips_enabled || check_weak)) + goto bad; + + if ((!((K[0] ^ K[4]) | (K[1] ^ K[5]))) && fips_enabled) + goto bad; + + ret = 0; +bad: + memzero_explicit(K, DES3_EDE_KEY_SIZE); + + return ret; +} + +/** + * crypto_des3_ede_verify_key - Check whether a DES3-EDE key is weak + * @tfm: the crypto algo + * @key: the key buffer + * + * Returns -EINVAL if the key is weak and the crypto TFM does not permit weak + * keys or when running in FIPS mode. Otherwise, 0 is returned. Note that some + * keys are rejected in FIPS mode even if weak keys are permitted by the TFM + * flags. + * + * It is the job of the caller to ensure that the size of the key equals + * DES3_EDE_KEY_SIZE. + */ +static inline int crypto_des3_ede_verify_key(struct crypto_tfm *tfm, + const u8 *key) +{ + return des3_ede_verify_key(key, DES3_EDE_KEY_SIZE, + crypto_tfm_get_flags(tfm) & + CRYPTO_TFM_REQ_FORBID_WEAK_KEYS); +} + +static inline int verify_skcipher_des_key(struct crypto_skcipher *tfm, + const u8 *key) +{ + return crypto_des_verify_key(crypto_skcipher_tfm(tfm), key); +} + +static inline int verify_skcipher_des3_key(struct crypto_skcipher *tfm, + const u8 *key) +{ + return crypto_des3_ede_verify_key(crypto_skcipher_tfm(tfm), key); +} + +static inline int verify_aead_des_key(struct crypto_aead *tfm, const u8 *key, + int keylen) +{ + if (keylen != DES_KEY_SIZE) + return -EINVAL; + return crypto_des_verify_key(crypto_aead_tfm(tfm), key); +} + +static inline int verify_aead_des3_key(struct crypto_aead *tfm, const u8 *key, + int keylen) +{ + if (keylen != DES3_EDE_KEY_SIZE) + return -EINVAL; + return crypto_des3_ede_verify_key(crypto_aead_tfm(tfm), key); +} + +#endif /* __CRYPTO_INTERNAL_DES_H */ -- cgit v1.3.1