mirror of
https://github.com/torvalds/linux.git
synced 2026-04-23 00:55:48 -04:00
ea2e6467ac
Currently only array maps are supported, but the implementation can be extended for other maps and objects. The hash is memoized only for exclusive and frozen maps as their content is stable until the exclusive program modifies the map. This is required for BPF signing, enabling a trusted loader program to verify a map's integrity. The loader retrieves the map's runtime hash from the kernel and compares it against an expected hash computed at build time. Signed-off-by: KP Singh <kpsingh@kernel.org> Link: https://lore.kernel.org/r/20250914215141.15144-7-kpsingh@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
163 lines
3.7 KiB
C
163 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/* Converted from tools/testing/selftests/bpf/verifier/map_ptr.c */
|
|
|
|
#include <linux/bpf.h>
|
|
#include <bpf/bpf_helpers.h>
|
|
#include "bpf_misc.h"
|
|
|
|
#define MAX_ENTRIES 11
|
|
|
|
struct test_val {
|
|
unsigned int index;
|
|
int foo[MAX_ENTRIES];
|
|
};
|
|
|
|
struct {
|
|
__uint(type, BPF_MAP_TYPE_ARRAY);
|
|
__uint(max_entries, 1);
|
|
__type(key, int);
|
|
__type(value, struct test_val);
|
|
} map_array_48b SEC(".maps");
|
|
|
|
struct other_val {
|
|
long long foo;
|
|
long long bar;
|
|
};
|
|
|
|
struct {
|
|
__uint(type, BPF_MAP_TYPE_HASH);
|
|
__uint(max_entries, 1);
|
|
__type(key, long long);
|
|
__type(value, struct other_val);
|
|
} map_hash_16b SEC(".maps");
|
|
|
|
SEC("socket")
|
|
__description("bpf_map_ptr: read with negative offset rejected")
|
|
__failure __msg("R1 is bpf_array invalid negative access: off=-8")
|
|
__failure_unpriv
|
|
__msg_unpriv("access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN")
|
|
__naked void read_with_negative_offset_rejected(void)
|
|
{
|
|
asm volatile (" \
|
|
r1 = r10; \
|
|
r1 = %[map_array_48b] ll; \
|
|
r6 = *(u64*)(r1 - 8); \
|
|
r0 = 1; \
|
|
exit; \
|
|
" :
|
|
: __imm_addr(map_array_48b)
|
|
: __clobber_all);
|
|
}
|
|
|
|
SEC("socket")
|
|
__description("bpf_map_ptr: write rejected")
|
|
__failure __msg("only read from bpf_array is supported")
|
|
__failure_unpriv
|
|
__msg_unpriv("access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN")
|
|
__naked void bpf_map_ptr_write_rejected(void)
|
|
{
|
|
asm volatile (" \
|
|
r0 = 0; \
|
|
*(u64*)(r10 - 8) = r0; \
|
|
r2 = r10; \
|
|
r2 += -8; \
|
|
r1 = %[map_array_48b] ll; \
|
|
*(u64*)(r1 + 0) = r2; \
|
|
r0 = 1; \
|
|
exit; \
|
|
" :
|
|
: __imm_addr(map_array_48b)
|
|
: __clobber_all);
|
|
}
|
|
|
|
/* The first element of struct bpf_map is a SHA256 hash of 32 bytes, accessing
|
|
* into this array is valid. The opts field is now at offset 33.
|
|
*/
|
|
SEC("socket")
|
|
__description("bpf_map_ptr: read non-existent field rejected")
|
|
__failure
|
|
__msg("cannot access ptr member ops with moff 32 in struct bpf_map with off 33 size 4")
|
|
__failure_unpriv
|
|
__msg_unpriv("access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN")
|
|
__flag(BPF_F_ANY_ALIGNMENT)
|
|
__naked void read_non_existent_field_rejected(void)
|
|
{
|
|
asm volatile (" \
|
|
r6 = 0; \
|
|
r1 = %[map_array_48b] ll; \
|
|
r6 = *(u32*)(r1 + 33); \
|
|
r0 = 1; \
|
|
exit; \
|
|
" :
|
|
: __imm_addr(map_array_48b)
|
|
: __clobber_all);
|
|
}
|
|
|
|
SEC("socket")
|
|
__description("bpf_map_ptr: read ops field accepted")
|
|
__success __failure_unpriv
|
|
__msg_unpriv("access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN")
|
|
__retval(1)
|
|
__naked void ptr_read_ops_field_accepted(void)
|
|
{
|
|
asm volatile (" \
|
|
r6 = 0; \
|
|
r1 = %[map_array_48b] ll; \
|
|
r6 = *(u64*)(r1 + 0); \
|
|
r0 = 1; \
|
|
exit; \
|
|
" :
|
|
: __imm_addr(map_array_48b)
|
|
: __clobber_all);
|
|
}
|
|
|
|
SEC("socket")
|
|
__description("bpf_map_ptr: r = 0, map_ptr = map_ptr + r")
|
|
__success __failure_unpriv
|
|
__msg_unpriv("R1 has pointer with unsupported alu operation")
|
|
__retval(0)
|
|
__naked void map_ptr_map_ptr_r(void)
|
|
{
|
|
asm volatile (" \
|
|
r0 = 0; \
|
|
*(u64*)(r10 - 8) = r0; \
|
|
r2 = r10; \
|
|
r2 += -8; \
|
|
r0 = 0; \
|
|
r1 = %[map_hash_16b] ll; \
|
|
r1 += r0; \
|
|
call %[bpf_map_lookup_elem]; \
|
|
r0 = 0; \
|
|
exit; \
|
|
" :
|
|
: __imm(bpf_map_lookup_elem),
|
|
__imm_addr(map_hash_16b)
|
|
: __clobber_all);
|
|
}
|
|
|
|
SEC("socket")
|
|
__description("bpf_map_ptr: r = 0, r = r + map_ptr")
|
|
__success __failure_unpriv
|
|
__msg_unpriv("R0 has pointer with unsupported alu operation")
|
|
__retval(0)
|
|
__naked void _0_r_r_map_ptr(void)
|
|
{
|
|
asm volatile (" \
|
|
r0 = 0; \
|
|
*(u64*)(r10 - 8) = r0; \
|
|
r2 = r10; \
|
|
r2 += -8; \
|
|
r1 = 0; \
|
|
r0 = %[map_hash_16b] ll; \
|
|
r1 += r0; \
|
|
call %[bpf_map_lookup_elem]; \
|
|
r0 = 0; \
|
|
exit; \
|
|
" :
|
|
: __imm(bpf_map_lookup_elem),
|
|
__imm_addr(map_hash_16b)
|
|
: __clobber_all);
|
|
}
|
|
|
|
char _license[] SEC("license") = "GPL";
|