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
10 struct test_val {
11 unsigned int index;
12 int foo[MAX_ENTRIES];
13 };
14
15 struct {
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
22 struct {
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
29 SEC("socket")
30 __description("pointer/scalar confusion in state equality check (way 1)")
31 __success __failure_unpriv __msg_unpriv("R0 leaks addr as return value")
__retval(POINTER_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_%=; \
45 l0_%=: r0 = r10; \
46 l1_%=: goto l2_%=; \
47 l2_%=: exit; \
48 " :
49 : __imm(bpf_map_lookup_elem),
50 __imm_addr(map_hash_8b)
51 : __clobber_all);
52 }
53
54 SEC("socket")
55 __description("pointer/scalar confusion in state equality check (way 2)")
56 __success __failure_unpriv __msg_unpriv("R0 leaks addr as return value")
__retval(POINTER_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_%=; \
70 l0_%=: r0 = *(u64*)(r0 + 0); \
71 l1_%=: exit; \
72 " :
73 : __imm(bpf_map_lookup_elem),
74 __imm_addr(map_hash_8b)
75 : __clobber_all);
76 }
77
78 SEC("lwt_in")
79 __description("liveness pruning and write screening")
80 __failure __msg("R0 !read_ok")
liveness_pruning_and_write_screening(void)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; \
89 l0_%=: if r2 >= 0 goto l1_%=; \
90 r0 = 0; \
91 l1_%=: exit; \
92 " ::: __clobber_all);
93 }
94
95 SEC("socket")
96 __description("varlen_map_value_access pruning")
97 __failure __msg("R0 unbounded memory access")
98 __failure_unpriv __msg_unpriv("R0 leaks addr")
__flag(BPF_F_ANY_ALIGNMENT)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; \
114 l1_%=: w1 <<= 2; \
115 r0 += r1; \
116 goto l2_%=; \
117 l2_%=: r1 = %[test_val_foo]; \
118 *(u64*)(r0 + 0) = r1; \
119 l0_%=: 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
128 SEC("tracepoint")
129 __description("search pruning: all branches should be verified (nop operation)")
130 __failure __msg("R6 invalid mem access 'scalar'")
should_be_verified_nop_operation(void)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_%=; \
145 l1_%=: r4 = 1; \
146 l2_%=: *(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; \
153 l0_%=: 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
161 SEC("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)
be_verified_invalid_stack_access(void)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_%=; \
182 l1_%=: *(u64*)(r10 - 24) = r4; \
183 l2_%=: call %[bpf_ktime_get_ns]; \
184 r5 = *(u64*)(r10 - 16); \
185 l0_%=: 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
193 SEC("tracepoint")
194 __description("precision tracking for u32 spill/fill")
195 __failure __msg("R0 min value is outside of the allowed memory range")
tracking_for_u32_spill_fill(void)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; \
204 l0_%=: /* 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; \
210 l1_%=: /* 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); \
223 l2_%=: 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
232 SEC("tracepoint")
233 __description("precision tracking for u32 spills, u64 fill")
234 __failure __msg("div by zero")
for_u32_spills_u64_fill(void)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; \
249 l0_%=: 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; \
257 l1_%=: /* 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; \
265 l2_%=: r0 = 0; \
266 exit; \
267 " :
268 : __imm(bpf_get_prandom_u32)
269 : __clobber_all);
270 }
271
272 SEC("socket")
273 __description("allocated_stack")
274 __success __msg("processed 15 insns")
275 __success_unpriv __msg_unpriv("") __log_level(1) __retval(0)
allocated_stack(void)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); \
288 l0_%=: if r0 != 0 goto l1_%=; \
289 l1_%=: if r0 != 0 goto l2_%=; \
290 l2_%=: if r0 != 0 goto l3_%=; \
291 l3_%=: if r0 != 0 goto l4_%=; \
292 l4_%=: 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
309 SEC("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")
__flag(BPF_F_TEST_STATE_FREQ)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; \
328 l0_%=: 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
339 char _license[] SEC("license") = "GPL";
340