1// SPDX-License-Identifier: GPL-2.0
2/* Converted from tools/testing/selftests/bpf/verifier/search_pruning.c */
3
4#include <linux/bpf.h>
5#include <bpf/bpf_helpers.h>
6#include "bpf_misc.h"
7
8#define MAX_ENTRIES 11
9
10struct test_val {
11 unsigned int index;
12 int foo[MAX_ENTRIES];
13};
14
15struct {
16 __uint(type, BPF_MAP_TYPE_HASH);
17 __uint(max_entries, 1);
18 __type(key, long long);
19 __type(value, struct test_val);
20} map_hash_48b SEC(".maps");
21
22struct {
23 __uint(type, BPF_MAP_TYPE_HASH);
24 __uint(max_entries, 1);
25 __type(key, long long);
26 __type(value, long long);
27} map_hash_8b SEC(".maps");
28
29SEC("socket")
30__description("pointer/scalar confusion in state equality check (way 1)")
31__success __failure_unpriv __msg_unpriv("R0 leaks addr as return value")
32__retval(POINTER_VALUE)
33__naked void state_equality_check_way_1(void)
34{
35 asm volatile (" \
36 r1 = 0; \
37 *(u64*)(r10 - 8) = r1; \
38 r2 = r10; \
39 r2 += -8; \
40 r1 = %[map_hash_8b] ll; \
41 call %[bpf_map_lookup_elem]; \
42 if r0 == 0 goto l0_%=; \
43 r0 = *(u64*)(r0 + 0); \
44 goto l1_%=; \
45l0_%=: r0 = r10; \
46l1_%=: goto l2_%=; \
47l2_%=: exit; \
48" :
49 : __imm(bpf_map_lookup_elem),
50 __imm_addr(map_hash_8b)
51 : __clobber_all);
52}
53
54SEC("socket")
55__description("pointer/scalar confusion in state equality check (way 2)")
56__success __failure_unpriv __msg_unpriv("R0 leaks addr as return value")
57__retval(POINTER_VALUE)
58__naked void state_equality_check_way_2(void)
59{
60 asm volatile (" \
61 r1 = 0; \
62 *(u64*)(r10 - 8) = r1; \
63 r2 = r10; \
64 r2 += -8; \
65 r1 = %[map_hash_8b] ll; \
66 call %[bpf_map_lookup_elem]; \
67 if r0 != 0 goto l0_%=; \
68 r0 = r10; \
69 goto l1_%=; \
70l0_%=: r0 = *(u64*)(r0 + 0); \
71l1_%=: exit; \
72" :
73 : __imm(bpf_map_lookup_elem),
74 __imm_addr(map_hash_8b)
75 : __clobber_all);
76}
77
78SEC("lwt_in")
79__description("liveness pruning and write screening")
80__failure __msg("R0 !read_ok")
81__naked void liveness_pruning_and_write_screening(void)
82{
83 asm volatile (" \
84 /* Get an unknown value */ \
85 r2 = *(u32*)(r1 + 0); \
86 /* branch conditions teach us nothing about R2 */\
87 if r2 >= 0 goto l0_%=; \
88 r0 = 0; \
89l0_%=: if r2 >= 0 goto l1_%=; \
90 r0 = 0; \
91l1_%=: exit; \
92" ::: __clobber_all);
93}
94
95SEC("socket")
96__description("varlen_map_value_access pruning")
97__failure __msg("R0 unbounded memory access")
98__failure_unpriv __msg_unpriv("R0 leaks addr")
99__flag(BPF_F_ANY_ALIGNMENT)
100__naked void varlen_map_value_access_pruning(void)
101{
102 asm volatile (" \
103 r1 = 0; \
104 *(u64*)(r10 - 8) = r1; \
105 r2 = r10; \
106 r2 += -8; \
107 r1 = %[map_hash_48b] ll; \
108 call %[bpf_map_lookup_elem]; \
109 if r0 == 0 goto l0_%=; \
110 r1 = *(u64*)(r0 + 0); \
111 w2 = %[max_entries]; \
112 if r2 s> r1 goto l1_%=; \
113 w1 = 0; \
114l1_%=: w1 <<= 2; \
115 r0 += r1; \
116 goto l2_%=; \
117l2_%=: r1 = %[test_val_foo]; \
118 *(u64*)(r0 + 0) = r1; \
119l0_%=: exit; \
120" :
121 : __imm(bpf_map_lookup_elem),
122 __imm_addr(map_hash_48b),
123 __imm_const(max_entries, MAX_ENTRIES),
124 __imm_const(test_val_foo, offsetof(struct test_val, foo))
125 : __clobber_all);
126}
127
128SEC("tracepoint")
129__description("search pruning: all branches should be verified (nop operation)")
130__failure __msg("R6 invalid mem access 'scalar'")
131__naked void should_be_verified_nop_operation(void)
132{
133 asm volatile (" \
134 r2 = r10; \
135 r2 += -8; \
136 r1 = 0; \
137 *(u64*)(r2 + 0) = r1; \
138 r1 = %[map_hash_8b] ll; \
139 call %[bpf_map_lookup_elem]; \
140 if r0 == 0 goto l0_%=; \
141 r3 = *(u64*)(r0 + 0); \
142 if r3 == 0xbeef goto l1_%=; \
143 r4 = 0; \
144 goto l2_%=; \
145l1_%=: r4 = 1; \
146l2_%=: *(u64*)(r10 - 16) = r4; \
147 call %[bpf_ktime_get_ns]; \
148 r5 = *(u64*)(r10 - 16); \
149 if r5 == 0 goto l0_%=; \
150 r6 = 0; \
151 r1 = 0xdead; \
152 *(u64*)(r6 + 0) = r1; \
153l0_%=: exit; \
154" :
155 : __imm(bpf_ktime_get_ns),
156 __imm(bpf_map_lookup_elem),
157 __imm_addr(map_hash_8b)
158 : __clobber_all);
159}
160
161SEC("socket")
162__description("search pruning: all branches should be verified (invalid stack access)")
163/* in privileged mode reads from uninitialized stack locations are permitted */
164__success __failure_unpriv
165__msg_unpriv("invalid read from stack off -16+0 size 8")
166__retval(0)
167__naked void be_verified_invalid_stack_access(void)
168{
169 asm volatile (" \
170 r2 = r10; \
171 r2 += -8; \
172 r1 = 0; \
173 *(u64*)(r2 + 0) = r1; \
174 r1 = %[map_hash_8b] ll; \
175 call %[bpf_map_lookup_elem]; \
176 if r0 == 0 goto l0_%=; \
177 r3 = *(u64*)(r0 + 0); \
178 r4 = 0; \
179 if r3 == 0xbeef goto l1_%=; \
180 *(u64*)(r10 - 16) = r4; \
181 goto l2_%=; \
182l1_%=: *(u64*)(r10 - 24) = r4; \
183l2_%=: call %[bpf_ktime_get_ns]; \
184 r5 = *(u64*)(r10 - 16); \
185l0_%=: exit; \
186" :
187 : __imm(bpf_ktime_get_ns),
188 __imm(bpf_map_lookup_elem),
189 __imm_addr(map_hash_8b)
190 : __clobber_all);
191}
192
193SEC("tracepoint")
194__description("precision tracking for u32 spill/fill")
195__failure __msg("R0 min value is outside of the allowed memory range")
196__naked void tracking_for_u32_spill_fill(void)
197{
198 asm volatile (" \
199 r7 = r1; \
200 call %[bpf_get_prandom_u32]; \
201 w6 = 32; \
202 if r0 == 0 goto l0_%=; \
203 w6 = 4; \
204l0_%=: /* Additional insns to introduce a pruning point. */\
205 call %[bpf_get_prandom_u32]; \
206 r3 = 0; \
207 r3 = 0; \
208 if r0 == 0 goto l1_%=; \
209 r3 = 0; \
210l1_%=: /* u32 spill/fill */ \
211 *(u32*)(r10 - 8) = r6; \
212 r8 = *(u32*)(r10 - 8); \
213 /* out-of-bound map value access for r6=32 */ \
214 r1 = 0; \
215 *(u64*)(r10 - 16) = r1; \
216 r2 = r10; \
217 r2 += -16; \
218 r1 = %[map_hash_8b] ll; \
219 call %[bpf_map_lookup_elem]; \
220 if r0 == 0 goto l2_%=; \
221 r0 += r8; \
222 r1 = *(u32*)(r0 + 0); \
223l2_%=: r0 = 0; \
224 exit; \
225" :
226 : __imm(bpf_get_prandom_u32),
227 __imm(bpf_map_lookup_elem),
228 __imm_addr(map_hash_8b)
229 : __clobber_all);
230}
231
232SEC("tracepoint")
233__description("precision tracking for u32 spills, u64 fill")
234__failure __msg("div by zero")
235__naked void for_u32_spills_u64_fill(void)
236{
237 asm volatile (" \
238 call %[bpf_get_prandom_u32]; \
239 r6 = r0; \
240 w7 = 0xffffffff; \
241 /* Additional insns to introduce a pruning point. */\
242 r3 = 1; \
243 r3 = 1; \
244 r3 = 1; \
245 r3 = 1; \
246 call %[bpf_get_prandom_u32]; \
247 if r0 == 0 goto l0_%=; \
248 r3 = 1; \
249l0_%=: w3 /= 0; \
250 /* u32 spills, u64 fill */ \
251 *(u32*)(r10 - 4) = r6; \
252 *(u32*)(r10 - 8) = r7; \
253 r8 = *(u64*)(r10 - 8); \
254 /* if r8 != X goto pc+1 r8 known in fallthrough branch */\
255 if r8 != 0xffffffff goto l1_%=; \
256 r3 = 1; \
257l1_%=: /* if r8 == X goto pc+1 condition always true on first\
258 * traversal, so starts backtracking to mark r8 as requiring\
259 * precision. r7 marked as needing precision. r6 not marked\
260 * since it's not tracked. \
261 */ \
262 if r8 == 0xffffffff goto l2_%=; \
263 /* fails if r8 correctly marked unknown after fill. */\
264 w3 /= 0; \
265l2_%=: r0 = 0; \
266 exit; \
267" :
268 : __imm(bpf_get_prandom_u32)
269 : __clobber_all);
270}
271
272SEC("socket")
273__description("allocated_stack")
274__success __msg("processed 15 insns")
275__success_unpriv __msg_unpriv("") __log_level(1) __retval(0)
276__naked void allocated_stack(void)
277{
278 asm volatile (" \
279 r6 = r1; \
280 call %[bpf_get_prandom_u32]; \
281 r7 = r0; \
282 if r0 == 0 goto l0_%=; \
283 r0 = 0; \
284 *(u64*)(r10 - 8) = r6; \
285 r6 = *(u64*)(r10 - 8); \
286 *(u8*)(r10 - 9) = r7; \
287 r7 = *(u8*)(r10 - 9); \
288l0_%=: if r0 != 0 goto l1_%=; \
289l1_%=: if r0 != 0 goto l2_%=; \
290l2_%=: if r0 != 0 goto l3_%=; \
291l3_%=: if r0 != 0 goto l4_%=; \
292l4_%=: exit; \
293" :
294 : __imm(bpf_get_prandom_u32)
295 : __clobber_all);
296}
297
298/* The test performs a conditional 64-bit write to a stack location
299 * fp[-8], this is followed by an unconditional 8-bit write to fp[-8],
300 * then data is read from fp[-8]. This sequence is unsafe.
301 *
302 * The test would be mistakenly marked as safe w/o dst register parent
303 * preservation in verifier.c:copy_register_state() function.
304 *
305 * Note the usage of BPF_F_TEST_STATE_FREQ to force creation of the
306 * checkpoint state after conditional 64-bit assignment.
307 */
308
309SEC("socket")
310__description("write tracking and register parent chain bug")
311/* in privileged mode reads from uninitialized stack locations are permitted */
312__success __failure_unpriv
313__msg_unpriv("invalid read from stack off -8+1 size 8")
314__retval(0) __flag(BPF_F_TEST_STATE_FREQ)
315__naked void and_register_parent_chain_bug(void)
316{
317 asm volatile (" \
318 /* r6 = ktime_get_ns() */ \
319 call %[bpf_ktime_get_ns]; \
320 r6 = r0; \
321 /* r0 = ktime_get_ns() */ \
322 call %[bpf_ktime_get_ns]; \
323 /* if r0 > r6 goto +1 */ \
324 if r0 > r6 goto l0_%=; \
325 /* *(u64 *)(r10 - 8) = 0xdeadbeef */ \
326 r0 = 0xdeadbeef; \
327 *(u64*)(r10 - 8) = r0; \
328l0_%=: r1 = 42; \
329 *(u8*)(r10 - 8) = r1; \
330 r2 = *(u64*)(r10 - 8); \
331 /* exit(0) */ \
332 r0 = 0; \
333 exit; \
334" :
335 : __imm(bpf_ktime_get_ns)
336 : __clobber_all);
337}
338
339char _license[] SEC("license") = "GPL";
340

source code of linux/tools/testing/selftests/bpf/progs/verifier_search_pruning.c