Commit d79a3549 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
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bpf: Consistently use BPF token throughout BPF verifier logic 



Remove remaining direct queries to perfmon_capable() and bpf_capable()
in BPF verifier logic and instead use BPF token (if available) to make
decisions about privileges.

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-9-andrii@kernel.org
parent bbc1d247

include/linux/bpf.h

+8 −8
Original line number Diff line number Diff line
@@ -2261,24 +2261,24 @@ extern int sysctl_unprivileged_bpf_disabled; 


bool bpf_token_capable(const struct bpf_token *token, int cap);



static inline bool bpf_allow_ptr_leaks(void)

static inline bool bpf_allow_ptr_leaks(const struct bpf_token *token)

{

	return perfmon_capable();

	return bpf_token_capable(token, CAP_PERFMON);

}



static inline bool bpf_allow_uninit_stack(void)

static inline bool bpf_allow_uninit_stack(const struct bpf_token *token)

{

	return perfmon_capable();

	return bpf_token_capable(token, CAP_PERFMON);

}



static inline bool bpf_bypass_spec_v1(void)

static inline bool bpf_bypass_spec_v1(const struct bpf_token *token)

{

	return cpu_mitigations_off() || perfmon_capable();

	return cpu_mitigations_off() || bpf_token_capable(token, CAP_PERFMON);

}



static inline bool bpf_bypass_spec_v4(void)

static inline bool bpf_bypass_spec_v4(const struct bpf_token *token)

{

	return cpu_mitigations_off() || perfmon_capable();

	return cpu_mitigations_off() || bpf_token_capable(token, CAP_PERFMON);

}



int bpf_map_new_fd(struct bpf_map *map, int flags);

include/linux/filter.h

+1 −1
Original line number Diff line number Diff line
@@ -1140,7 +1140,7 @@ static inline bool bpf_jit_blinding_enabled(struct bpf_prog *prog) 
		return false;

	if (!bpf_jit_harden)

		return false;

	if (bpf_jit_harden == 1 && bpf_capable())

	if (bpf_jit_harden == 1 && bpf_token_capable(prog->aux->token, CAP_BPF))

		return false;



	return true;

kernel/bpf/arraymap.c

+1 −1
Original line number Diff line number Diff line
@@ -82,7 +82,7 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr) 
	bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;

	int numa_node = bpf_map_attr_numa_node(attr);

	u32 elem_size, index_mask, max_entries;

	bool bypass_spec_v1 = bpf_bypass_spec_v1();

	bool bypass_spec_v1 = bpf_bypass_spec_v1(NULL);

	u64 array_size, mask64;

	struct bpf_array *array;

kernel/bpf/core.c

+1 −1
Original line number Diff line number Diff line
@@ -682,7 +682,7 @@ static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp) 
void bpf_prog_kallsyms_add(struct bpf_prog *fp)

{

	if (!bpf_prog_kallsyms_candidate(fp) ||

	    !bpf_capable())

	    !bpf_token_capable(fp->aux->token, CAP_BPF))

		return;



	bpf_prog_ksym_set_addr(fp);

kernel/bpf/verifier.c

+6 −7
Original line number Diff line number Diff line
@@ -20830,7 +20830,12 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3 
	env->prog = *prog;

	env->ops = bpf_verifier_ops[env->prog->type];

	env->fd_array = make_bpfptr(attr->fd_array, uattr.is_kernel);

	is_priv = bpf_capable();









	env->allow_ptr_leaks = bpf_allow_ptr_leaks(env->prog->aux->token);









	env->allow_uninit_stack = bpf_allow_uninit_stack(env->prog->aux->token);









	env->bypass_spec_v1 = bpf_bypass_spec_v1(env->prog->aux->token);









	env->bypass_spec_v4 = bpf_bypass_spec_v4(env->prog->aux->token);









	env->bpf_capable = is_priv = bpf_token_capable(env->prog->aux->token, CAP_BPF);

















	bpf_get_btf_vmlinux();
















@@ -20862,12 +20867,6 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3







	if (attr->prog_flags & BPF_F_ANY_ALIGNMENT)









		env->strict_alignment = false;

















	env->allow_ptr_leaks = bpf_allow_ptr_leaks();









	env->allow_uninit_stack = bpf_allow_uninit_stack();









	env->bypass_spec_v1 = bpf_bypass_spec_v1();









	env->bypass_spec_v4 = bpf_bypass_spec_v4();









	env->bpf_capable = bpf_capable();

















	if (is_priv)









		env->test_state_freq = attr->prog_flags & BPF_F_TEST_STATE_FREQ;









	env->test_reg_invariants = attr->prog_flags & BPF_F_TEST_REG_INVARIANTS;