From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- tools/testing/selftests/bpf/progs/dynptr_fail.c | 1688 +++++++++++++++++++++++ 1 file changed, 1688 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/dynptr_fail.c (limited to 'tools/testing/selftests/bpf/progs/dynptr_fail.c') diff --git a/tools/testing/selftests/bpf/progs/dynptr_fail.c b/tools/testing/selftests/bpf/progs/dynptr_fail.c new file mode 100644 index 0000000000..7ce7e827d5 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/dynptr_fail.c @@ -0,0 +1,1688 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Facebook */ + +#include +#include +#include +#include +#include +#include +#include "bpf_misc.h" +#include "bpf_kfuncs.h" + +char _license[] SEC("license") = "GPL"; + +struct test_info { + int x; + struct bpf_dynptr ptr; +}; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, struct bpf_dynptr); +} array_map1 SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, struct test_info); +} array_map2 SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, __u32); +} array_map3 SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, __u64); +} array_map4 SEC(".maps"); + +struct sample { + int pid; + long value; + char comm[16]; +}; + +struct { + __uint(type, BPF_MAP_TYPE_RINGBUF); + __uint(max_entries, 4096); +} ringbuf SEC(".maps"); + +int err, val; + +static int get_map_val_dynptr(struct bpf_dynptr *ptr) +{ + __u32 key = 0, *map_val; + + bpf_map_update_elem(&array_map3, &key, &val, 0); + + map_val = bpf_map_lookup_elem(&array_map3, &key); + if (!map_val) + return -ENOENT; + + bpf_dynptr_from_mem(map_val, sizeof(*map_val), 0, ptr); + + return 0; +} + +/* Every bpf_ringbuf_reserve_dynptr call must have a corresponding + * bpf_ringbuf_submit/discard_dynptr call + */ +SEC("?raw_tp") +__failure __msg("Unreleased reference id=2") +int ringbuf_missing_release1(void *ctx) +{ + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr); + + /* missing a call to bpf_ringbuf_discard/submit_dynptr */ + + return 0; +} + +SEC("?raw_tp") +__failure __msg("Unreleased reference id=4") +int ringbuf_missing_release2(void *ctx) +{ + struct bpf_dynptr ptr1, ptr2; + struct sample *sample; + + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr1); + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr2); + + sample = bpf_dynptr_data(&ptr1, 0, sizeof(*sample)); + if (!sample) { + bpf_ringbuf_discard_dynptr(&ptr1, 0); + bpf_ringbuf_discard_dynptr(&ptr2, 0); + return 0; + } + + bpf_ringbuf_submit_dynptr(&ptr1, 0); + + /* missing a call to bpf_ringbuf_discard/submit_dynptr on ptr2 */ + + return 0; +} + +static int missing_release_callback_fn(__u32 index, void *data) +{ + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr); + + /* missing a call to bpf_ringbuf_discard/submit_dynptr */ + + return 0; +} + +/* Any dynptr initialized within a callback must have bpf_dynptr_put called */ +SEC("?raw_tp") +__failure __msg("Unreleased reference id") +int ringbuf_missing_release_callback(void *ctx) +{ + bpf_loop(10, missing_release_callback_fn, NULL, 0); + return 0; +} + +/* Can't call bpf_ringbuf_submit/discard_dynptr on a non-initialized dynptr */ +SEC("?raw_tp") +__failure __msg("arg 1 is an unacquired reference") +int ringbuf_release_uninit_dynptr(void *ctx) +{ + struct bpf_dynptr ptr; + + /* this should fail */ + bpf_ringbuf_submit_dynptr(&ptr, 0); + + return 0; +} + +/* A dynptr can't be used after it has been invalidated */ +SEC("?raw_tp") +__failure __msg("Expected an initialized dynptr as arg #3") +int use_after_invalid(void *ctx) +{ + struct bpf_dynptr ptr; + char read_data[64]; + + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(read_data), 0, &ptr); + + bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0, 0); + + bpf_ringbuf_submit_dynptr(&ptr, 0); + + /* this should fail */ + bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0, 0); + + return 0; +} + +/* Can't call non-dynptr ringbuf APIs on a dynptr ringbuf sample */ +SEC("?raw_tp") +__failure __msg("type=mem expected=ringbuf_mem") +int ringbuf_invalid_api(void *ctx) +{ + struct bpf_dynptr ptr; + struct sample *sample; + + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr); + sample = bpf_dynptr_data(&ptr, 0, sizeof(*sample)); + if (!sample) + goto done; + + sample->pid = 123; + + /* invalid API use. need to use dynptr API to submit/discard */ + bpf_ringbuf_submit(sample, 0); + +done: + bpf_ringbuf_discard_dynptr(&ptr, 0); + return 0; +} + +/* Can't add a dynptr to a map */ +SEC("?raw_tp") +__failure __msg("invalid indirect read from stack") +int add_dynptr_to_map1(void *ctx) +{ + struct bpf_dynptr ptr; + int key = 0; + + bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr); + + /* this should fail */ + bpf_map_update_elem(&array_map1, &key, &ptr, 0); + + bpf_ringbuf_submit_dynptr(&ptr, 0); + + return 0; +} + +/* Can't add a struct with an embedded dynptr to a map */ +SEC("?raw_tp") +__failure __msg("invalid indirect read from stack") +int add_dynptr_to_map2(void *ctx) +{ + struct test_info x; + int key = 0; + + bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &x.ptr); + + /* this should fail */ + bpf_map_update_elem(&array_map2, &key, &x, 0); + + bpf_ringbuf_submit_dynptr(&x.ptr, 0); + + return 0; +} + +/* A data slice can't be accessed out of bounds */ +SEC("?raw_tp") +__failure __msg("value is outside of the allowed memory range") +int data_slice_out_of_bounds_ringbuf(void *ctx) +{ + struct bpf_dynptr ptr; + void *data; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 8, 0, &ptr); + + data = bpf_dynptr_data(&ptr, 0, 8); + if (!data) + goto done; + + /* can't index out of bounds of the data slice */ + val = *((char *)data + 8); + +done: + bpf_ringbuf_submit_dynptr(&ptr, 0); + return 0; +} + +/* A data 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(struct __sk_buff *skb) +{ + struct bpf_dynptr ptr; + struct ethhdr *hdr; + char buffer[sizeof(*hdr)] = {}; + + bpf_dynptr_from_skb(skb, 0, &ptr); + + hdr = bpf_dynptr_slice_rdwr(&ptr, 0, buffer, sizeof(buffer)); + if (!hdr) + return SK_DROP; + + /* this should fail */ + *(__u8*)(hdr + 1) = 1; + + 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) +{ + __u32 map_val; + struct bpf_dynptr ptr; + void *data; + + get_map_val_dynptr(&ptr); + + data = bpf_dynptr_data(&ptr, 0, sizeof(map_val)); + if (!data) + return 0; + + /* can't index out of bounds of the data slice */ + val = *((char *)data + (sizeof(map_val) + 1)); + + return 0; +} + +/* A data slice can't be used after it has been released */ +SEC("?raw_tp") +__failure __msg("invalid mem access 'scalar'") +int data_slice_use_after_release1(void *ctx) +{ + struct bpf_dynptr ptr; + struct sample *sample; + + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr); + sample = bpf_dynptr_data(&ptr, 0, sizeof(*sample)); + if (!sample) + goto done; + + sample->pid = 123; + + bpf_ringbuf_submit_dynptr(&ptr, 0); + + /* this should fail */ + val = sample->pid; + + return 0; + +done: + bpf_ringbuf_discard_dynptr(&ptr, 0); + return 0; +} + +/* A data slice can't be used after it has been released. + * + * This tests the case where the data slice tracks a dynptr (ptr2) + * that is at a non-zero offset from the frame pointer (ptr1 is at fp, + * ptr2 is at fp - 16). + */ +SEC("?raw_tp") +__failure __msg("invalid mem access 'scalar'") +int data_slice_use_after_release2(void *ctx) +{ + struct bpf_dynptr ptr1, ptr2; + struct sample *sample; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr1); + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr2); + + sample = bpf_dynptr_data(&ptr2, 0, sizeof(*sample)); + if (!sample) + goto done; + + sample->pid = 23; + + bpf_ringbuf_submit_dynptr(&ptr2, 0); + + /* this should fail */ + sample->pid = 23; + + bpf_ringbuf_submit_dynptr(&ptr1, 0); + + return 0; + +done: + bpf_ringbuf_discard_dynptr(&ptr2, 0); + bpf_ringbuf_discard_dynptr(&ptr1, 0); + return 0; +} + +/* A data slice must be first checked for NULL */ +SEC("?raw_tp") +__failure __msg("invalid mem access 'mem_or_null'") +int data_slice_missing_null_check1(void *ctx) +{ + struct bpf_dynptr ptr; + void *data; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 8, 0, &ptr); + + data = bpf_dynptr_data(&ptr, 0, 8); + + /* missing if (!data) check */ + + /* this should fail */ + *(__u8 *)data = 3; + + bpf_ringbuf_submit_dynptr(&ptr, 0); + return 0; +} + +/* A data slice can't be dereferenced if it wasn't checked for null */ +SEC("?raw_tp") +__failure __msg("invalid mem access 'mem_or_null'") +int data_slice_missing_null_check2(void *ctx) +{ + struct bpf_dynptr ptr; + __u64 *data1, *data2; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &ptr); + + data1 = bpf_dynptr_data(&ptr, 0, 8); + data2 = bpf_dynptr_data(&ptr, 0, 8); + if (data1) + /* this should fail */ + *data2 = 3; + + bpf_ringbuf_discard_dynptr(&ptr, 0); + return 0; +} + +/* Can't pass in a dynptr as an arg to a helper function that doesn't take in a + * dynptr argument + */ +SEC("?raw_tp") +__failure __msg("invalid indirect read from stack") +int invalid_helper1(void *ctx) +{ + struct bpf_dynptr ptr; + + get_map_val_dynptr(&ptr); + + /* this should fail */ + bpf_strncmp((const char *)&ptr, sizeof(ptr), "hello!"); + + return 0; +} + +/* A dynptr can't be passed into a helper function at a non-zero offset */ +SEC("?raw_tp") +__failure __msg("cannot pass in dynptr at an offset=-8") +int invalid_helper2(void *ctx) +{ + struct bpf_dynptr ptr; + char read_data[64]; + + get_map_val_dynptr(&ptr); + + /* this should fail */ + bpf_dynptr_read(read_data, sizeof(read_data), (void *)&ptr + 8, 0, 0); + return 0; +} + +/* A bpf_dynptr is invalidated if it's been written into */ +SEC("?raw_tp") +__failure __msg("Expected an initialized dynptr as arg #1") +int invalid_write1(void *ctx) +{ + struct bpf_dynptr ptr; + void *data; + __u8 x = 0; + + get_map_val_dynptr(&ptr); + + memcpy(&ptr, &x, sizeof(x)); + + /* this should fail */ + data = bpf_dynptr_data(&ptr, 0, 1); + __sink(data); + + return 0; +} + +/* + * A bpf_dynptr can't be used as a dynptr if it has been written into at a fixed + * offset + */ +SEC("?raw_tp") +__failure __msg("cannot overwrite referenced dynptr") +int invalid_write2(void *ctx) +{ + struct bpf_dynptr ptr; + char read_data[64]; + __u8 x = 0; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr); + + memcpy((void *)&ptr + 8, &x, sizeof(x)); + + /* this should fail */ + bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0, 0); + + bpf_ringbuf_submit_dynptr(&ptr, 0); + + return 0; +} + +/* + * A bpf_dynptr can't be used as a dynptr if it has been written into at a + * non-const offset + */ +SEC("?raw_tp") +__failure __msg("cannot overwrite referenced dynptr") +int invalid_write3(void *ctx) +{ + struct bpf_dynptr ptr; + char stack_buf[16]; + unsigned long len; + __u8 x = 0; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 8, 0, &ptr); + + memcpy(stack_buf, &val, sizeof(val)); + len = stack_buf[0] & 0xf; + + memcpy((void *)&ptr + len, &x, sizeof(x)); + + /* this should fail */ + bpf_ringbuf_submit_dynptr(&ptr, 0); + + return 0; +} + +static int invalid_write4_callback(__u32 index, void *data) +{ + *(__u32 *)data = 123; + + return 0; +} + +/* If the dynptr is written into in a callback function, it should + * be invalidated as a dynptr + */ +SEC("?raw_tp") +__failure __msg("cannot overwrite referenced dynptr") +int invalid_write4(void *ctx) +{ + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr); + + bpf_loop(10, invalid_write4_callback, &ptr, 0); + + /* this should fail */ + bpf_ringbuf_submit_dynptr(&ptr, 0); + + return 0; +} + +/* A globally-defined bpf_dynptr can't be used (it must reside as a stack frame) */ +struct bpf_dynptr global_dynptr; + +SEC("?raw_tp") +__failure __msg("type=map_value expected=fp") +int global(void *ctx) +{ + /* this should fail */ + bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &global_dynptr); + + bpf_ringbuf_discard_dynptr(&global_dynptr, 0); + + return 0; +} + +/* A direct read should fail */ +SEC("?raw_tp") +__failure __msg("invalid read from stack") +int invalid_read1(void *ctx) +{ + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr); + + /* this should fail */ + val = *(int *)&ptr; + + bpf_ringbuf_discard_dynptr(&ptr, 0); + + return 0; +} + +/* A direct read at an offset should fail */ +SEC("?raw_tp") +__failure __msg("cannot pass in dynptr at an offset") +int invalid_read2(void *ctx) +{ + struct bpf_dynptr ptr; + char read_data[64]; + + get_map_val_dynptr(&ptr); + + /* this should fail */ + bpf_dynptr_read(read_data, sizeof(read_data), (void *)&ptr + 1, 0, 0); + + return 0; +} + +/* A direct read at an offset into the lower stack slot should fail */ +SEC("?raw_tp") +__failure __msg("invalid read from stack") +int invalid_read3(void *ctx) +{ + struct bpf_dynptr ptr1, ptr2; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &ptr1); + bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &ptr2); + + /* this should fail */ + memcpy(&val, (void *)&ptr1 + 8, sizeof(val)); + + bpf_ringbuf_discard_dynptr(&ptr1, 0); + bpf_ringbuf_discard_dynptr(&ptr2, 0); + + return 0; +} + +static int invalid_read4_callback(__u32 index, void *data) +{ + /* this should fail */ + val = *(__u32 *)data; + + return 0; +} + +/* A direct read within a callback function should fail */ +SEC("?raw_tp") +__failure __msg("invalid read from stack") +int invalid_read4(void *ctx) +{ + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr); + + bpf_loop(10, invalid_read4_callback, &ptr, 0); + + bpf_ringbuf_submit_dynptr(&ptr, 0); + + return 0; +} + +/* Initializing a dynptr on an offset should fail */ +SEC("?raw_tp") +__failure __msg("cannot pass in dynptr at an offset=0") +int invalid_offset(void *ctx) +{ + struct bpf_dynptr ptr; + + /* this should fail */ + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr + 1); + + bpf_ringbuf_discard_dynptr(&ptr, 0); + + return 0; +} + +/* Can't release a dynptr twice */ +SEC("?raw_tp") +__failure __msg("arg 1 is an unacquired reference") +int release_twice(void *ctx) +{ + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &ptr); + + bpf_ringbuf_discard_dynptr(&ptr, 0); + + /* this second release should fail */ + bpf_ringbuf_discard_dynptr(&ptr, 0); + + return 0; +} + +static int release_twice_callback_fn(__u32 index, void *data) +{ + /* this should fail */ + bpf_ringbuf_discard_dynptr(data, 0); + + return 0; +} + +/* Test that releasing a dynptr twice, where one of the releases happens + * within a callback function, fails + */ +SEC("?raw_tp") +__failure __msg("arg 1 is an unacquired reference") +int release_twice_callback(void *ctx) +{ + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 32, 0, &ptr); + + bpf_ringbuf_discard_dynptr(&ptr, 0); + + bpf_loop(10, release_twice_callback_fn, &ptr, 0); + + return 0; +} + +/* Reject unsupported local mem types for dynptr_from_mem API */ +SEC("?raw_tp") +__failure __msg("Unsupported reg type fp for bpf_dynptr_from_mem data") +int dynptr_from_mem_invalid_api(void *ctx) +{ + struct bpf_dynptr ptr; + int x = 0; + + /* this should fail */ + bpf_dynptr_from_mem(&x, sizeof(x), 0, &ptr); + + return 0; +} + +SEC("?tc") +__failure __msg("cannot overwrite referenced dynptr") __log_level(2) +int dynptr_pruning_overwrite(struct __sk_buff *ctx) +{ + asm volatile ( + "r9 = 0xeB9F; \ + r6 = %[ringbuf] ll; \ + r1 = r6; \ + r2 = 8; \ + r3 = 0; \ + r4 = r10; \ + r4 += -16; \ + call %[bpf_ringbuf_reserve_dynptr]; \ + if r0 == 0 goto pjmp1; \ + goto pjmp2; \ + pjmp1: \ + *(u64 *)(r10 - 16) = r9; \ + pjmp2: \ + r1 = r10; \ + r1 += -16; \ + r2 = 0; \ + call %[bpf_ringbuf_discard_dynptr]; " + : + : __imm(bpf_ringbuf_reserve_dynptr), + __imm(bpf_ringbuf_discard_dynptr), + __imm_addr(ringbuf) + : __clobber_all + ); + return 0; +} + +SEC("?tc") +__success __msg("12: safe") __log_level(2) +int dynptr_pruning_stacksafe(struct __sk_buff *ctx) +{ + asm volatile ( + "r9 = 0xeB9F; \ + r6 = %[ringbuf] ll; \ + r1 = r6; \ + r2 = 8; \ + r3 = 0; \ + r4 = r10; \ + r4 += -16; \ + call %[bpf_ringbuf_reserve_dynptr]; \ + if r0 == 0 goto stjmp1; \ + goto stjmp2; \ + stjmp1: \ + r9 = r9; \ + stjmp2: \ + r1 = r10; \ + r1 += -16; \ + r2 = 0; \ + call %[bpf_ringbuf_discard_dynptr]; " + : + : __imm(bpf_ringbuf_reserve_dynptr), + __imm(bpf_ringbuf_discard_dynptr), + __imm_addr(ringbuf) + : __clobber_all + ); + return 0; +} + +SEC("?tc") +__failure __msg("cannot overwrite referenced dynptr") __log_level(2) +int dynptr_pruning_type_confusion(struct __sk_buff *ctx) +{ + asm volatile ( + "r6 = %[array_map4] ll; \ + r7 = %[ringbuf] ll; \ + r1 = r6; \ + r2 = r10; \ + r2 += -8; \ + r9 = 0; \ + *(u64 *)(r2 + 0) = r9; \ + r3 = r10; \ + r3 += -24; \ + r9 = 0xeB9FeB9F; \ + *(u64 *)(r10 - 16) = r9; \ + *(u64 *)(r10 - 24) = r9; \ + r9 = 0; \ + r4 = 0; \ + r8 = r2; \ + call %[bpf_map_update_elem]; \ + r1 = r6; \ + r2 = r8; \ + call %[bpf_map_lookup_elem]; \ + if r0 != 0 goto tjmp1; \ + exit; \ + tjmp1: \ + r8 = r0; \ + r1 = r7; \ + r2 = 8; \ + r3 = 0; \ + r4 = r10; \ + r4 += -16; \ + r0 = *(u64 *)(r0 + 0); \ + call %[bpf_ringbuf_reserve_dynptr]; \ + if r0 == 0 goto tjmp2; \ + r8 = r8; \ + r8 = r8; \ + r8 = r8; \ + r8 = r8; \ + r8 = r8; \ + r8 = r8; \ + r8 = r8; \ + goto tjmp3; \ + tjmp2: \ + *(u64 *)(r10 - 8) = r9; \ + *(u64 *)(r10 - 16) = r9; \ + r1 = r8; \ + r1 += 8; \ + r2 = 0; \ + r3 = 0; \ + r4 = r10; \ + r4 += -16; \ + call %[bpf_dynptr_from_mem]; \ + tjmp3: \ + r1 = r10; \ + r1 += -16; \ + r2 = 0; \ + call %[bpf_ringbuf_discard_dynptr]; " + : + : __imm(bpf_map_update_elem), + __imm(bpf_map_lookup_elem), + __imm(bpf_ringbuf_reserve_dynptr), + __imm(bpf_dynptr_from_mem), + __imm(bpf_ringbuf_discard_dynptr), + __imm_addr(array_map4), + __imm_addr(ringbuf) + : __clobber_all + ); + return 0; +} + +SEC("?tc") +__failure __msg("dynptr has to be at a constant offset") __log_level(2) +int dynptr_var_off_overwrite(struct __sk_buff *ctx) +{ + asm volatile ( + "r9 = 16; \ + *(u32 *)(r10 - 4) = r9; \ + r8 = *(u32 *)(r10 - 4); \ + if r8 >= 0 goto vjmp1; \ + r0 = 1; \ + exit; \ + vjmp1: \ + if r8 <= 16 goto vjmp2; \ + r0 = 1; \ + exit; \ + vjmp2: \ + r8 &= 16; \ + r1 = %[ringbuf] ll; \ + r2 = 8; \ + r3 = 0; \ + r4 = r10; \ + r4 += -32; \ + r4 += r8; \ + call %[bpf_ringbuf_reserve_dynptr]; \ + r9 = 0xeB9F; \ + *(u64 *)(r10 - 16) = r9; \ + r1 = r10; \ + r1 += -32; \ + r1 += r8; \ + r2 = 0; \ + call %[bpf_ringbuf_discard_dynptr]; " + : + : __imm(bpf_ringbuf_reserve_dynptr), + __imm(bpf_ringbuf_discard_dynptr), + __imm_addr(ringbuf) + : __clobber_all + ); + return 0; +} + +SEC("?tc") +__failure __msg("cannot overwrite referenced dynptr") __log_level(2) +int dynptr_partial_slot_invalidate(struct __sk_buff *ctx) +{ + asm volatile ( + "r6 = %[ringbuf] ll; \ + r7 = %[array_map4] ll; \ + r1 = r7; \ + r2 = r10; \ + r2 += -8; \ + r9 = 0; \ + *(u64 *)(r2 + 0) = r9; \ + r3 = r2; \ + r4 = 0; \ + r8 = r2; \ + call %[bpf_map_update_elem]; \ + r1 = r7; \ + r2 = r8; \ + call %[bpf_map_lookup_elem]; \ + if r0 != 0 goto sjmp1; \ + exit; \ + sjmp1: \ + r7 = r0; \ + r1 = r6; \ + r2 = 8; \ + r3 = 0; \ + r4 = r10; \ + r4 += -24; \ + call %[bpf_ringbuf_reserve_dynptr]; \ + *(u64 *)(r10 - 16) = r9; \ + r1 = r7; \ + r2 = 8; \ + r3 = 0; \ + r4 = r10; \ + r4 += -16; \ + call %[bpf_dynptr_from_mem]; \ + r1 = r10; \ + r1 += -512; \ + r2 = 488; \ + r3 = r10; \ + r3 += -24; \ + r4 = 0; \ + r5 = 0; \ + call %[bpf_dynptr_read]; \ + r8 = 1; \ + if r0 != 0 goto sjmp2; \ + r8 = 0; \ + sjmp2: \ + r1 = r10; \ + r1 += -24; \ + r2 = 0; \ + call %[bpf_ringbuf_discard_dynptr]; " + : + : __imm(bpf_map_update_elem), + __imm(bpf_map_lookup_elem), + __imm(bpf_ringbuf_reserve_dynptr), + __imm(bpf_ringbuf_discard_dynptr), + __imm(bpf_dynptr_from_mem), + __imm(bpf_dynptr_read), + __imm_addr(ringbuf), + __imm_addr(array_map4) + : __clobber_all + ); + return 0; +} + +/* Test that it is allowed to overwrite unreferenced dynptr. */ +SEC("?raw_tp") +__success +int dynptr_overwrite_unref(void *ctx) +{ + struct bpf_dynptr ptr; + + if (get_map_val_dynptr(&ptr)) + return 0; + if (get_map_val_dynptr(&ptr)) + return 0; + if (get_map_val_dynptr(&ptr)) + return 0; + + return 0; +} + +/* Test that slices are invalidated on reinitializing a dynptr. */ +SEC("?raw_tp") +__failure __msg("invalid mem access 'scalar'") +int dynptr_invalidate_slice_reinit(void *ctx) +{ + struct bpf_dynptr ptr; + __u8 *p; + + if (get_map_val_dynptr(&ptr)) + return 0; + p = bpf_dynptr_data(&ptr, 0, 1); + if (!p) + return 0; + if (get_map_val_dynptr(&ptr)) + return 0; + /* this should fail */ + return *p; +} + +/* Invalidation of dynptr slices on destruction of dynptr should not miss + * mem_or_null pointers. + */ +SEC("?raw_tp") +__failure __msg("R1 type=scalar expected=percpu_ptr_") +int dynptr_invalidate_slice_or_null(void *ctx) +{ + struct bpf_dynptr ptr; + __u8 *p; + + if (get_map_val_dynptr(&ptr)) + return 0; + + p = bpf_dynptr_data(&ptr, 0, 1); + *(__u8 *)&ptr = 0; + /* this should fail */ + bpf_this_cpu_ptr(p); + return 0; +} + +/* Destruction of dynptr should also any slices obtained from it */ +SEC("?raw_tp") +__failure __msg("R7 invalid mem access 'scalar'") +int dynptr_invalidate_slice_failure(void *ctx) +{ + struct bpf_dynptr ptr1; + struct bpf_dynptr ptr2; + __u8 *p1, *p2; + + if (get_map_val_dynptr(&ptr1)) + return 0; + if (get_map_val_dynptr(&ptr2)) + return 0; + + p1 = bpf_dynptr_data(&ptr1, 0, 1); + if (!p1) + return 0; + p2 = bpf_dynptr_data(&ptr2, 0, 1); + if (!p2) + return 0; + + *(__u8 *)&ptr1 = 0; + /* this should fail */ + return *p1; +} + +/* Invalidation of slices should be scoped and should not prevent dereferencing + * slices of another dynptr after destroying unrelated dynptr + */ +SEC("?raw_tp") +__success +int dynptr_invalidate_slice_success(void *ctx) +{ + struct bpf_dynptr ptr1; + struct bpf_dynptr ptr2; + __u8 *p1, *p2; + + if (get_map_val_dynptr(&ptr1)) + return 1; + if (get_map_val_dynptr(&ptr2)) + return 1; + + p1 = bpf_dynptr_data(&ptr1, 0, 1); + if (!p1) + return 1; + p2 = bpf_dynptr_data(&ptr2, 0, 1); + if (!p2) + return 1; + + *(__u8 *)&ptr1 = 0; + return *p2; +} + +/* Overwriting referenced dynptr should be rejected */ +SEC("?raw_tp") +__failure __msg("cannot overwrite referenced dynptr") +int dynptr_overwrite_ref(void *ctx) +{ + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr); + /* this should fail */ + if (get_map_val_dynptr(&ptr)) + bpf_ringbuf_discard_dynptr(&ptr, 0); + return 0; +} + +/* Reject writes to dynptr slot from bpf_dynptr_read */ +SEC("?raw_tp") +__failure __msg("potential write to dynptr at off=-16") +int dynptr_read_into_slot(void *ctx) +{ + union { + struct { + char _pad[48]; + struct bpf_dynptr ptr; + }; + char buf[64]; + } data; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &data.ptr); + /* this should fail */ + bpf_dynptr_read(data.buf, sizeof(data.buf), &data.ptr, 0, 0); + + return 0; +} + +/* bpf_dynptr_slice()s are read-only and cannot be written to */ +SEC("?tc") +__failure __msg("R0 cannot write into rdonly_mem") +int skb_invalid_slice_write(struct __sk_buff *skb) +{ + struct bpf_dynptr ptr; + struct ethhdr *hdr; + char buffer[sizeof(*hdr)] = {}; + + bpf_dynptr_from_skb(skb, 0, &ptr); + + hdr = bpf_dynptr_slice(&ptr, 0, buffer, sizeof(buffer)); + if (!hdr) + return SK_DROP; + + /* this should fail */ + hdr->h_proto = 1; + + return SK_PASS; +} + +/* The read-only data slice is invalidated whenever a helper changes packet data */ +SEC("?tc") +__failure __msg("invalid mem access 'scalar'") +int skb_invalid_data_slice1(struct __sk_buff *skb) +{ + struct bpf_dynptr ptr; + struct ethhdr *hdr; + char buffer[sizeof(*hdr)] = {}; + + bpf_dynptr_from_skb(skb, 0, &ptr); + + hdr = bpf_dynptr_slice(&ptr, 0, buffer, sizeof(buffer)); + if (!hdr) + return SK_DROP; + + val = hdr->h_proto; + + if (bpf_skb_pull_data(skb, skb->len)) + return SK_DROP; + + /* this should fail */ + val = hdr->h_proto; + + return SK_PASS; +} + +/* The read-write data slice is invalidated whenever a helper changes packet data */ +SEC("?tc") +__failure __msg("invalid mem access 'scalar'") +int skb_invalid_data_slice2(struct __sk_buff *skb) +{ + struct bpf_dynptr ptr; + struct ethhdr *hdr; + char buffer[sizeof(*hdr)] = {}; + + bpf_dynptr_from_skb(skb, 0, &ptr); + + hdr = bpf_dynptr_slice_rdwr(&ptr, 0, buffer, sizeof(buffer)); + if (!hdr) + return SK_DROP; + + hdr->h_proto = 123; + + if (bpf_skb_pull_data(skb, skb->len)) + return SK_DROP; + + /* this should fail */ + hdr->h_proto = 1; + + return SK_PASS; +} + +/* The read-only data slice is invalidated whenever bpf_dynptr_write() is called */ +SEC("?tc") +__failure __msg("invalid mem access 'scalar'") +int skb_invalid_data_slice3(struct __sk_buff *skb) +{ + char write_data[64] = "hello there, world!!"; + struct bpf_dynptr ptr; + struct ethhdr *hdr; + char buffer[sizeof(*hdr)] = {}; + + bpf_dynptr_from_skb(skb, 0, &ptr); + + hdr = bpf_dynptr_slice(&ptr, 0, buffer, sizeof(buffer)); + if (!hdr) + return SK_DROP; + + val = hdr->h_proto; + + bpf_dynptr_write(&ptr, 0, write_data, sizeof(write_data), 0); + + /* this should fail */ + val = hdr->h_proto; + + return SK_PASS; +} + +/* The read-write data slice is invalidated whenever bpf_dynptr_write() is called */ +SEC("?tc") +__failure __msg("invalid mem access 'scalar'") +int skb_invalid_data_slice4(struct __sk_buff *skb) +{ + char write_data[64] = "hello there, world!!"; + struct bpf_dynptr ptr; + struct ethhdr *hdr; + char buffer[sizeof(*hdr)] = {}; + + bpf_dynptr_from_skb(skb, 0, &ptr); + hdr = bpf_dynptr_slice_rdwr(&ptr, 0, buffer, sizeof(buffer)); + if (!hdr) + return SK_DROP; + + hdr->h_proto = 123; + + bpf_dynptr_write(&ptr, 0, write_data, sizeof(write_data), 0); + + /* this should fail */ + hdr->h_proto = 1; + + return SK_PASS; +} + +/* The read-only data slice is invalidated whenever a helper changes packet data */ +SEC("?xdp") +__failure __msg("invalid mem access 'scalar'") +int xdp_invalid_data_slice1(struct xdp_md *xdp) +{ + struct bpf_dynptr ptr; + struct ethhdr *hdr; + char buffer[sizeof(*hdr)] = {}; + + bpf_dynptr_from_xdp(xdp, 0, &ptr); + hdr = bpf_dynptr_slice(&ptr, 0, buffer, sizeof(buffer)); + if (!hdr) + return SK_DROP; + + val = hdr->h_proto; + + if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(*hdr))) + return XDP_DROP; + + /* this should fail */ + val = hdr->h_proto; + + return XDP_PASS; +} + +/* The read-write data slice is invalidated whenever a helper changes packet data */ +SEC("?xdp") +__failure __msg("invalid mem access 'scalar'") +int xdp_invalid_data_slice2(struct xdp_md *xdp) +{ + struct bpf_dynptr ptr; + struct ethhdr *hdr; + char buffer[sizeof(*hdr)] = {}; + + bpf_dynptr_from_xdp(xdp, 0, &ptr); + hdr = bpf_dynptr_slice_rdwr(&ptr, 0, buffer, sizeof(buffer)); + if (!hdr) + return SK_DROP; + + hdr->h_proto = 9; + + if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(*hdr))) + return XDP_DROP; + + /* this should fail */ + hdr->h_proto = 1; + + return XDP_PASS; +} + +/* Only supported prog type can create skb-type dynptrs */ +SEC("?raw_tp") +__failure __msg("calling kernel function bpf_dynptr_from_skb is not allowed") +int skb_invalid_ctx(void *ctx) +{ + struct bpf_dynptr ptr; + + /* this should fail */ + bpf_dynptr_from_skb(ctx, 0, &ptr); + + return 0; +} + +/* Reject writes to dynptr slot for uninit arg */ +SEC("?raw_tp") +__failure __msg("potential write to dynptr at off=-16") +int uninit_write_into_slot(void *ctx) +{ + struct { + char buf[64]; + struct bpf_dynptr ptr; + } data; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 80, 0, &data.ptr); + /* this should fail */ + bpf_get_current_comm(data.buf, 80); + + return 0; +} + +/* Only supported prog type can create xdp-type dynptrs */ +SEC("?raw_tp") +__failure __msg("calling kernel function bpf_dynptr_from_xdp is not allowed") +int xdp_invalid_ctx(void *ctx) +{ + struct bpf_dynptr ptr; + + /* this should fail */ + bpf_dynptr_from_xdp(ctx, 0, &ptr); + + return 0; +} + +__u32 hdr_size = sizeof(struct ethhdr); +/* Can't pass in variable-sized len to bpf_dynptr_slice */ +SEC("?tc") +__failure __msg("unbounded memory access") +int dynptr_slice_var_len1(struct __sk_buff *skb) +{ + struct bpf_dynptr ptr; + struct ethhdr *hdr; + char buffer[sizeof(*hdr)] = {}; + + bpf_dynptr_from_skb(skb, 0, &ptr); + + /* this should fail */ + hdr = bpf_dynptr_slice(&ptr, 0, buffer, hdr_size); + if (!hdr) + return SK_DROP; + + return SK_PASS; +} + +/* Can't pass in variable-sized len to bpf_dynptr_slice */ +SEC("?tc") +__failure __msg("must be a known constant") +int dynptr_slice_var_len2(struct __sk_buff *skb) +{ + char buffer[sizeof(struct ethhdr)] = {}; + struct bpf_dynptr ptr; + struct ethhdr *hdr; + + bpf_dynptr_from_skb(skb, 0, &ptr); + + if (hdr_size <= sizeof(buffer)) { + /* this should fail */ + hdr = bpf_dynptr_slice_rdwr(&ptr, 0, buffer, hdr_size); + if (!hdr) + return SK_DROP; + hdr->h_proto = 12; + } + + return SK_PASS; +} + +static int callback(__u32 index, void *data) +{ + *(__u32 *)data = 123; + + return 0; +} + +/* If the dynptr is written into in a callback function, its data + * slices should be invalidated as well. + */ +SEC("?raw_tp") +__failure __msg("invalid mem access 'scalar'") +int invalid_data_slices(void *ctx) +{ + struct bpf_dynptr ptr; + __u32 *slice; + + if (get_map_val_dynptr(&ptr)) + return 0; + + slice = bpf_dynptr_data(&ptr, 0, sizeof(__u32)); + if (!slice) + return 0; + + bpf_loop(10, callback, &ptr, 0); + + /* this should fail */ + *slice = 1; + + return 0; +} + +/* Program types that don't allow writes to packet data should fail if + * bpf_dynptr_slice_rdwr is called + */ +SEC("cgroup_skb/ingress") +__failure __msg("the prog does not allow writes to packet data") +int invalid_slice_rdwr_rdonly(struct __sk_buff *skb) +{ + char buffer[sizeof(struct ethhdr)] = {}; + struct bpf_dynptr ptr; + struct ethhdr *hdr; + + bpf_dynptr_from_skb(skb, 0, &ptr); + + /* this should fail since cgroup_skb doesn't allow + * changing packet data + */ + hdr = bpf_dynptr_slice_rdwr(&ptr, 0, buffer, sizeof(buffer)); + __sink(hdr); + + return 0; +} + +/* bpf_dynptr_adjust can only be called on initialized dynptrs */ +SEC("?raw_tp") +__failure __msg("Expected an initialized dynptr as arg #1") +int dynptr_adjust_invalid(void *ctx) +{ + struct bpf_dynptr ptr; + + /* this should fail */ + bpf_dynptr_adjust(&ptr, 1, 2); + + return 0; +} + +/* bpf_dynptr_is_null can only be called on initialized dynptrs */ +SEC("?raw_tp") +__failure __msg("Expected an initialized dynptr as arg #1") +int dynptr_is_null_invalid(void *ctx) +{ + struct bpf_dynptr ptr; + + /* this should fail */ + bpf_dynptr_is_null(&ptr); + + return 0; +} + +/* bpf_dynptr_is_rdonly can only be called on initialized dynptrs */ +SEC("?raw_tp") +__failure __msg("Expected an initialized dynptr as arg #1") +int dynptr_is_rdonly_invalid(void *ctx) +{ + struct bpf_dynptr ptr; + + /* this should fail */ + bpf_dynptr_is_rdonly(&ptr); + + return 0; +} + +/* bpf_dynptr_size can only be called on initialized dynptrs */ +SEC("?raw_tp") +__failure __msg("Expected an initialized dynptr as arg #1") +int dynptr_size_invalid(void *ctx) +{ + struct bpf_dynptr ptr; + + /* this should fail */ + bpf_dynptr_size(&ptr); + + return 0; +} + +/* Only initialized dynptrs can be cloned */ +SEC("?raw_tp") +__failure __msg("Expected an initialized dynptr as arg #1") +int clone_invalid1(void *ctx) +{ + struct bpf_dynptr ptr1; + struct bpf_dynptr ptr2; + + /* this should fail */ + bpf_dynptr_clone(&ptr1, &ptr2); + + return 0; +} + +/* Can't overwrite an existing dynptr when cloning */ +SEC("?xdp") +__failure __msg("cannot overwrite referenced dynptr") +int clone_invalid2(struct xdp_md *xdp) +{ + struct bpf_dynptr ptr1; + struct bpf_dynptr clone; + + bpf_dynptr_from_xdp(xdp, 0, &ptr1); + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &clone); + + /* this should fail */ + bpf_dynptr_clone(&ptr1, &clone); + + bpf_ringbuf_submit_dynptr(&clone, 0); + + return 0; +} + +/* Invalidating a dynptr should invalidate its clones */ +SEC("?raw_tp") +__failure __msg("Expected an initialized dynptr as arg #3") +int clone_invalidate1(void *ctx) +{ + struct bpf_dynptr clone; + struct bpf_dynptr ptr; + char read_data[64]; + + bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr); + + bpf_dynptr_clone(&ptr, &clone); + + bpf_ringbuf_submit_dynptr(&ptr, 0); + + /* this should fail */ + bpf_dynptr_read(read_data, sizeof(read_data), &clone, 0, 0); + + return 0; +} + +/* Invalidating a dynptr should invalidate its parent */ +SEC("?raw_tp") +__failure __msg("Expected an initialized dynptr as arg #3") +int clone_invalidate2(void *ctx) +{ + struct bpf_dynptr ptr; + struct bpf_dynptr clone; + char read_data[64]; + + bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr); + + bpf_dynptr_clone(&ptr, &clone); + + bpf_ringbuf_submit_dynptr(&clone, 0); + + /* this should fail */ + bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0, 0); + + return 0; +} + +/* Invalidating a dynptr should invalidate its siblings */ +SEC("?raw_tp") +__failure __msg("Expected an initialized dynptr as arg #3") +int clone_invalidate3(void *ctx) +{ + struct bpf_dynptr ptr; + struct bpf_dynptr clone1; + struct bpf_dynptr clone2; + char read_data[64]; + + bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr); + + bpf_dynptr_clone(&ptr, &clone1); + + bpf_dynptr_clone(&ptr, &clone2); + + bpf_ringbuf_submit_dynptr(&clone2, 0); + + /* this should fail */ + bpf_dynptr_read(read_data, sizeof(read_data), &clone1, 0, 0); + + return 0; +} + +/* Invalidating a dynptr should invalidate any data slices + * of its clones + */ +SEC("?raw_tp") +__failure __msg("invalid mem access 'scalar'") +int clone_invalidate4(void *ctx) +{ + struct bpf_dynptr ptr; + struct bpf_dynptr 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) + return 0; + + bpf_ringbuf_submit_dynptr(&ptr, 0); + + /* this should fail */ + *data = 123; + + return 0; +} + +/* Invalidating a dynptr should invalidate any data slices + * of its parent + */ +SEC("?raw_tp") +__failure __msg("invalid mem access 'scalar'") +int clone_invalidate5(void *ctx) +{ + struct bpf_dynptr ptr; + struct bpf_dynptr 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); + + bpf_ringbuf_submit_dynptr(&clone, 0); + + /* this should fail */ + *data = 123; + + return 0; +} + +/* Invalidating a dynptr should invalidate any data slices + * of its sibling + */ +SEC("?raw_tp") +__failure __msg("invalid mem access 'scalar'") +int clone_invalidate6(void *ctx) +{ + struct bpf_dynptr ptr; + struct bpf_dynptr clone1; + struct bpf_dynptr clone2; + int *data; + + bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr); + + bpf_dynptr_clone(&ptr, &clone1); + + bpf_dynptr_clone(&ptr, &clone2); + + data = bpf_dynptr_data(&clone1, 0, sizeof(val)); + if (!data) + return 0; + + bpf_ringbuf_submit_dynptr(&clone2, 0); + + /* this should fail */ + *data = 123; + + return 0; +} + +/* A skb clone's data slices should be invalid anytime packet data changes */ +SEC("?tc") +__failure __msg("invalid mem access 'scalar'") +int clone_skb_packet_data(struct __sk_buff *skb) +{ + char buffer[sizeof(__u32)] = {}; + struct bpf_dynptr clone; + struct bpf_dynptr ptr; + __u32 *data; + + bpf_dynptr_from_skb(skb, 0, &ptr); + + bpf_dynptr_clone(&ptr, &clone); + data = bpf_dynptr_slice_rdwr(&clone, 0, buffer, sizeof(buffer)); + if (!data) + return XDP_DROP; + + if (bpf_skb_pull_data(skb, skb->len)) + return SK_DROP; + + /* this should fail */ + *data = 123; + + return 0; +} + +/* A xdp clone's data slices should be invalid anytime packet data changes */ +SEC("?xdp") +__failure __msg("invalid mem access 'scalar'") +int clone_xdp_packet_data(struct xdp_md *xdp) +{ + char buffer[sizeof(__u32)] = {}; + struct bpf_dynptr clone; + struct bpf_dynptr ptr; + struct ethhdr *hdr; + __u32 *data; + + bpf_dynptr_from_xdp(xdp, 0, &ptr); + + bpf_dynptr_clone(&ptr, &clone); + data = bpf_dynptr_slice_rdwr(&clone, 0, buffer, sizeof(buffer)); + if (!data) + return XDP_DROP; + + if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(*hdr))) + return XDP_DROP; + + /* this should fail */ + *data = 123; + + return 0; +} + +/* Buffers that are provided must be sufficiently long */ +SEC("?cgroup_skb/egress") +__failure __msg("memory, len pair leads to invalid memory access") +int test_dynptr_skb_small_buff(struct __sk_buff *skb) +{ + struct bpf_dynptr ptr; + char buffer[8] = {}; + __u64 *data; + + if (bpf_dynptr_from_skb(skb, 0, &ptr)) { + err = 1; + return 1; + } + + /* This may return NULL. SKB may require a buffer */ + data = bpf_dynptr_slice(&ptr, 0, buffer, 9); + + return !!data; +} -- cgit v1.2.3