With CONFIG_CFI_CLANG enabled, the kernel strictly enforces that indirect function calls use a function pointer type that matches the target function. I ran into the following type mismatch when running BPF self-tests: CFI failure at bpf_obj_free_fields+0x190/0x238 (target: bpf_crypto_ctx_release+0x0/0x94; expected type: 0xa488ebfc) Internal error: Oops - CFI: 00000000f2008228 [#1] SMP ... As bpf_crypto_ctx_release() is also used in BPF programs and using a void pointer as the argument would make the verifier unhappy, add a simple stub function with the correct type and register it as the destructor kfunc instead. Signed-off-by: Sami Tolvanen --- kernel/bpf/crypto.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/crypto.c b/kernel/bpf/crypto.c index 94854cd9c4cc..b703b1d1c282 100644 --- a/kernel/bpf/crypto.c +++ b/kernel/bpf/crypto.c @@ -261,6 +261,11 @@ __bpf_kfunc void bpf_crypto_ctx_release(struct bpf_crypto_ctx *ctx) call_rcu(&ctx->rcu, crypto_free_cb); } +__bpf_kfunc void __bpf_crypto_ctx_release(void *ctx) +{ + bpf_crypto_ctx_release(ctx); +} + static int bpf_crypto_crypt(const struct bpf_crypto_ctx *ctx, const struct bpf_dynptr_kern *src, const struct bpf_dynptr_kern *dst, @@ -368,7 +373,7 @@ static const struct btf_kfunc_id_set crypt_kfunc_set = { BTF_ID_LIST(bpf_crypto_dtor_ids) BTF_ID(struct, bpf_crypto_ctx) -BTF_ID(func, bpf_crypto_ctx_release) +BTF_ID(func, __bpf_crypto_ctx_release) static int __init crypto_kfunc_init(void) { -- 2.50.1.470.g6ba607880d-goog