diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/verifier_map_ptr.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_map_ptr.c | 39 |
1 files changed, 34 insertions, 5 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_map_ptr.c b/tools/testing/selftests/bpf/progs/verifier_map_ptr.c index e2767d27d8aa..e0a65835c861 100644 --- a/tools/testing/selftests/bpf/progs/verifier_map_ptr.c +++ b/tools/testing/selftests/bpf/progs/verifier_map_ptr.c @@ -70,13 +70,17 @@ __naked void bpf_map_ptr_write_rejected(void) : __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. +/* + * struct bpf_map starts with the SHA256 hash sha[32] at offset 0 (a readable + * byte array), followed by the ops pointer at offset 32 and the inner_map_meta + * pointer at offset 40. Reading a u32 at offset 41 reaches into the middle of + * the inner_map_meta pointer, i.e. a partial pointer access, which is + * rejected. */ 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") +__msg("cannot access ptr member inner_map_meta with moff 40 in struct bpf_map with off 41 size 4") __failure_unpriv __msg_unpriv("access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN") __flag(BPF_F_ANY_ALIGNMENT) @@ -85,7 +89,32 @@ __naked void read_non_existent_field_rejected(void) asm volatile (" \ r6 = 0; \ r1 = %[map_array_48b] ll; \ - r6 = *(u32*)(r1 + 33); \ + r6 = *(u32*)(r1 + 41); \ + r0 = 1; \ + exit; \ +" : + : __imm_addr(map_array_48b) + : __clobber_all); +} + +/* + * The sha byte array spans offsets 0..31 (mend 32). Reading a u32 at offset + * 30 starts inside sha but extends past its end, which the verifier rejects + * as an out-of-bounds scalar access. + */ +SEC("socket") +__description("bpf_map_ptr: read beyond sha field rejected") +__failure +__msg("access beyond the end of member sha (mend:32) in struct bpf_map with off 30 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_beyond_sha_field_rejected(void) +{ + asm volatile (" \ + r6 = 0; \ + r1 = %[map_array_48b] ll; \ + r6 = *(u32*)(r1 + 30); \ r0 = 1; \ exit; \ " : @@ -103,7 +132,7 @@ __naked void ptr_read_ops_field_accepted(void) asm volatile (" \ r6 = 0; \ r1 = %[map_array_48b] ll; \ - r6 = *(u64*)(r1 + 0); \ + r6 = *(u64*)(r1 + 32); \ r0 = 1; \ exit; \ " : |