diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/dynptr_fail.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/dynptr_fail.c | 375 |
1 files changed, 374 insertions, 1 deletions
diff --git a/tools/testing/selftests/bpf/progs/dynptr_fail.c b/tools/testing/selftests/bpf/progs/dynptr_fail.c index bd8f15229f5c..b62773ce5219 100644 --- a/tools/testing/selftests/bpf/progs/dynptr_fail.c +++ b/tools/testing/selftests/bpf/progs/dynptr_fail.c @@ -269,6 +269,26 @@ int data_slice_out_of_bounds_skb(struct __sk_buff *skb) return SK_PASS; } +/* A metadata slice can't be accessed out of bounds */ +SEC("?tc") +__failure __msg("value is outside of the allowed memory range") +int data_slice_out_of_bounds_skb_meta(struct __sk_buff *skb) +{ + struct bpf_dynptr meta; + __u8 *md; + + bpf_dynptr_from_skb_meta(skb, 0, &meta); + + md = bpf_dynptr_slice_rdwr(&meta, 0, NULL, sizeof(*md)); + if (!md) + return SK_DROP; + + /* this should fail */ + *(md + 1) = 42; + + return SK_PASS; +} + SEC("?raw_tp") __failure __msg("value is outside of the allowed memory range") int data_slice_out_of_bounds_map_value(void *ctx) @@ -1089,6 +1109,26 @@ int skb_invalid_slice_write(struct __sk_buff *skb) return SK_PASS; } +/* bpf_dynptr_slice()s are read-only and cannot be written to */ +SEC("?tc") +__failure __msg("R{{[0-9]+}} cannot write into rdonly_mem") +int skb_meta_invalid_slice_write(struct __sk_buff *skb) +{ + struct bpf_dynptr meta; + __u8 *md; + + bpf_dynptr_from_skb_meta(skb, 0, &meta); + + md = bpf_dynptr_slice(&meta, 0, NULL, sizeof(*md)); + if (!md) + return SK_DROP; + + /* this should fail */ + *md = 42; + + return SK_PASS; +} + /* The read-only data slice is invalidated whenever a helper changes packet data */ SEC("?tc") __failure __msg("invalid mem access 'scalar'") @@ -1192,6 +1232,188 @@ int skb_invalid_data_slice4(struct __sk_buff *skb) return SK_PASS; } +/* Read-only skb data slice is invalidated on write to skb metadata */ +SEC("?tc") +__failure __msg("invalid mem access 'scalar'") +int ro_skb_slice_invalid_after_metadata_write(struct __sk_buff *skb) +{ + struct bpf_dynptr data, meta; + __u8 *d; + + bpf_dynptr_from_skb(skb, 0, &data); + bpf_dynptr_from_skb_meta(skb, 0, &meta); + + d = bpf_dynptr_slice(&data, 0, NULL, sizeof(*d)); + if (!d) + return SK_DROP; + + bpf_dynptr_write(&meta, 0, "x", 1, 0); + + /* this should fail */ + val = *d; + + return SK_PASS; +} + +/* Read-write skb data slice is invalidated on write to skb metadata */ +SEC("?tc") +__failure __msg("invalid mem access 'scalar'") +int rw_skb_slice_invalid_after_metadata_write(struct __sk_buff *skb) +{ + struct bpf_dynptr data, meta; + __u8 *d; + + bpf_dynptr_from_skb(skb, 0, &data); + bpf_dynptr_from_skb_meta(skb, 0, &meta); + + d = bpf_dynptr_slice_rdwr(&data, 0, NULL, sizeof(*d)); + if (!d) + return SK_DROP; + + bpf_dynptr_write(&meta, 0, "x", 1, 0); + + /* this should fail */ + *d = 42; + + return SK_PASS; +} + +/* Read-only skb metadata slice is invalidated on write to skb data */ +SEC("?tc") +__failure __msg("invalid mem access 'scalar'") +int ro_skb_meta_slice_invalid_after_payload_write(struct __sk_buff *skb) +{ + struct bpf_dynptr data, meta; + __u8 *md; + + bpf_dynptr_from_skb(skb, 0, &data); + bpf_dynptr_from_skb_meta(skb, 0, &meta); + + md = bpf_dynptr_slice(&meta, 0, NULL, sizeof(*md)); + if (!md) + return SK_DROP; + + bpf_dynptr_write(&data, 0, "x", 1, 0); + + /* this should fail */ + val = *md; + + return SK_PASS; +} + +/* Read-write skb metadata slice is invalidated on write to skb data slice */ +SEC("?tc") +__failure __msg("invalid mem access 'scalar'") +int rw_skb_meta_slice_invalid_after_payload_write(struct __sk_buff *skb) +{ + struct bpf_dynptr data, meta; + __u8 *md; + + bpf_dynptr_from_skb(skb, 0, &data); + bpf_dynptr_from_skb_meta(skb, 0, &meta); + + md = bpf_dynptr_slice_rdwr(&meta, 0, NULL, sizeof(*md)); + if (!md) + return SK_DROP; + + bpf_dynptr_write(&data, 0, "x", 1, 0); + + /* this should fail */ + *md = 42; + + return SK_PASS; +} + +/* Read-only skb metadata slice is invalidated whenever a helper changes packet data */ +SEC("?tc") +__failure __msg("invalid mem access 'scalar'") +int ro_skb_meta_slice_invalid_after_payload_helper(struct __sk_buff *skb) +{ + struct bpf_dynptr meta; + __u8 *md; + + bpf_dynptr_from_skb_meta(skb, 0, &meta); + + md = bpf_dynptr_slice(&meta, 0, NULL, sizeof(*md)); + if (!md) + return SK_DROP; + + if (bpf_skb_pull_data(skb, skb->len)) + return SK_DROP; + + /* this should fail */ + val = *md; + + return SK_PASS; +} + +/* Read-write skb metadata slice is invalidated whenever a helper changes packet data */ +SEC("?tc") +__failure __msg("invalid mem access 'scalar'") +int rw_skb_meta_slice_invalid_after_payload_helper(struct __sk_buff *skb) +{ + struct bpf_dynptr meta; + __u8 *md; + + bpf_dynptr_from_skb_meta(skb, 0, &meta); + + md = bpf_dynptr_slice_rdwr(&meta, 0, NULL, sizeof(*md)); + if (!md) + return SK_DROP; + + if (bpf_skb_pull_data(skb, skb->len)) + return SK_DROP; + + /* this should fail */ + *md = 42; + + return SK_PASS; +} + +/* Read-only skb metadata slice is invalidated on write to skb metadata */ +SEC("?tc") +__failure __msg("invalid mem access 'scalar'") +int ro_skb_meta_slice_invalid_after_metadata_write(struct __sk_buff *skb) +{ + struct bpf_dynptr meta; + __u8 *md; + + bpf_dynptr_from_skb_meta(skb, 0, &meta); + + md = bpf_dynptr_slice(&meta, 0, NULL, sizeof(*md)); + if (!md) + return SK_DROP; + + bpf_dynptr_write(&meta, 0, "x", 1, 0); + + /* this should fail */ + val = *md; + + return SK_PASS; +} + +/* Read-write skb metadata slice is invalidated on write to skb metadata */ +SEC("?tc") +__failure __msg("invalid mem access 'scalar'") +int rw_skb_meta_slice_invalid_after_metadata_write(struct __sk_buff *skb) +{ + struct bpf_dynptr meta; + __u8 *md; + + bpf_dynptr_from_skb_meta(skb, 0, &meta); + + md = bpf_dynptr_slice_rdwr(&meta, 0, NULL, sizeof(*md)); + if (!md) + return SK_DROP; + + bpf_dynptr_write(&meta, 0, "x", 1, 0); + + /* this should fail */ + *md = 42; + + return SK_PASS; +} + /* The read-only data slice is invalidated whenever a helper changes packet data */ SEC("?xdp") __failure __msg("invalid mem access 'scalar'") @@ -1243,7 +1465,7 @@ int xdp_invalid_data_slice2(struct xdp_md *xdp) } /* Only supported prog type can create skb-type dynptrs */ -SEC("?raw_tp") +SEC("?xdp") __failure __msg("calling kernel function bpf_dynptr_from_skb is not allowed") int skb_invalid_ctx(void *ctx) { @@ -1255,6 +1477,19 @@ int skb_invalid_ctx(void *ctx) return 0; } +/* Only supported prog type can create skb_meta-type dynptrs */ +SEC("?raw_tp") +__failure __msg("calling kernel function bpf_dynptr_from_skb_meta is not allowed") +int skb_meta_invalid_ctx(void *ctx) +{ + struct bpf_dynptr meta; + + /* this should fail */ + bpf_dynptr_from_skb_meta(ctx, 0, &meta); + + return 0; +} + SEC("fentry/skb_tx_error") __failure __msg("must be referenced or trusted") int BPF_PROG(skb_invalid_ctx_fentry, void *skb) @@ -1665,6 +1900,29 @@ int clone_skb_packet_data(struct __sk_buff *skb) return 0; } +/* A skb clone's metadata slice becomes invalid anytime packet data changes */ +SEC("?tc") +__failure __msg("invalid mem access 'scalar'") +int clone_skb_packet_meta(struct __sk_buff *skb) +{ + struct bpf_dynptr clone, meta; + __u8 *md; + + bpf_dynptr_from_skb_meta(skb, 0, &meta); + bpf_dynptr_clone(&meta, &clone); + md = bpf_dynptr_slice_rdwr(&clone, 0, NULL, sizeof(*md)); + if (!md) + return SK_DROP; + + if (bpf_skb_pull_data(skb, skb->len)) + return SK_DROP; + + /* this should fail */ + *md = 42; + + return 0; +} + /* A xdp clone's data slices should be invalid anytime packet data changes */ SEC("?xdp") __failure __msg("invalid mem access 'scalar'") @@ -1735,3 +1993,118 @@ int test_dynptr_reg_type(void *ctx) global_call_bpf_dynptr((const struct bpf_dynptr *)current); return 0; } + +/* Overwriting a referenced dynptr is allowed if a clone still holds the ref */ +SEC("?raw_tp") +__success +int dynptr_overwrite_ref_with_clone(void *ctx) +{ + struct bpf_dynptr ptr, clone; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr); + + bpf_dynptr_clone(&ptr, &clone); + + /* Overwrite the original - clone still holds the ref */ + *(volatile __u8 *)&ptr = 0; + + bpf_ringbuf_discard_dynptr(&clone, 0); + + return 0; +} + +/* Overwriting the last referenced dynptr should still be rejected */ +SEC("?raw_tp") +__failure __msg("cannot overwrite referenced dynptr") +int dynptr_overwrite_ref_last_clone(void *ctx) +{ + struct bpf_dynptr ptr, clone; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr); + + bpf_dynptr_clone(&ptr, &clone); + + /* Overwrite the original - clone still holds the ref, OK */ + *(volatile __u8 *)&ptr = 0; + + /* Overwrite the last holder - this should fail */ + *(volatile __u8 *)&clone = 0; + + return 0; +} + +/* Overwriting a clone should be allowed if the original still holds the ref */ +SEC("?raw_tp") +__success +int dynptr_overwrite_clone_with_original(void *ctx) +{ + struct bpf_dynptr ptr, clone; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr); + + bpf_dynptr_clone(&ptr, &clone); + + /* Overwrite the clone - original still holds the ref */ + *(volatile __u8 *)&clone = 0; + + bpf_ringbuf_discard_dynptr(&ptr, 0); + + return 0; +} + +/* Data slices from the destroyed dynptr should be invalidated */ +SEC("?raw_tp") +__failure __msg("invalid mem access 'scalar'") +int dynptr_overwrite_ref_invalidate_slice(void *ctx) +{ + struct bpf_dynptr ptr, clone; + int *data; + + bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr); + + data = bpf_dynptr_data(&ptr, 0, sizeof(val)); + if (!data) + return 0; + + bpf_dynptr_clone(&ptr, &clone); + + /* Overwrite the original - clone holds the ref */ + *(volatile __u8 *)&ptr = 0; + + /* data was from the original dynptr, should be invalid now */ + *data = 123; + + return 0; +} + +/* + * Data slices from a dynptr clone should remain valid after + * overwriting the original dynptr + */ +SEC("?raw_tp") +__success +int dynptr_overwrite_ref_clone_slice_valid(void *ctx) +{ + struct bpf_dynptr ptr, clone; + int *data; + + bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr); + + bpf_dynptr_clone(&ptr, &clone); + + data = bpf_dynptr_data(&clone, 0, sizeof(val)); + if (!data) { + bpf_ringbuf_discard_dynptr(&clone, 0); + return 0; + } + + /* Overwrite the original - clone holds the ref */ + *(volatile __u8 *)&ptr = 0; + + /* data is from the clone, should still be valid */ + *data = 123; + + bpf_ringbuf_discard_dynptr(&clone, 0); + + return 0; +} |