Pirama Arumuga Nainar | 799172d | 2016-03-03 15:50:30 -0800 | [diff] [blame^] | 1 | // Regression test for https://crbug.com/502974, where ASan was unable to read |
| 2 | // the binary name because of sandbox restrictions. |
| 3 | // This test uses seccomp-BPF to restrict the readlink() system call and makes |
| 4 | // sure ASan is still able to |
| 5 | // RUN: not ls /usr/include/linux/seccomp.h || ( %clang_asan %s -o %t && not %run %t 2>&1 | FileCheck %s ) |
| 6 | // UNSUPPORTED: android |
| 7 | |
| 8 | #include <errno.h> |
| 9 | #include <stddef.h> |
| 10 | #include <stdlib.h> |
| 11 | #include <stdio.h> |
| 12 | #include <sys/prctl.h> |
| 13 | #include <sys/syscall.h> |
| 14 | #include <linux/filter.h> |
| 15 | #include <linux/seccomp.h> |
| 16 | |
| 17 | #ifndef __NR_readlink |
| 18 | # define __NR_readlink __NR_readlinkat |
| 19 | #endif |
| 20 | |
| 21 | #define syscall_nr (offsetof(struct seccomp_data, nr)) |
| 22 | |
| 23 | void corrupt() { |
| 24 | void *p = malloc(10); |
| 25 | free(p); |
| 26 | free(p); |
| 27 | } |
| 28 | |
| 29 | int main() { |
| 30 | prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); |
| 31 | |
| 32 | struct sock_filter filter[] = { |
| 33 | /* Grab the system call number */ |
| 34 | BPF_STMT(BPF_LD + BPF_W + BPF_ABS, syscall_nr), |
| 35 | // If this is __NR_readlink, |
| 36 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, __NR_readlink, 0, 1), |
| 37 | // return with EPERM, |
| 38 | BPF_STMT(BPF_RET + BPF_K, SECCOMP_RET_ERRNO | EPERM), |
| 39 | // otherwise allow the syscall. |
| 40 | BPF_STMT(BPF_RET + BPF_K, SECCOMP_RET_ALLOW) |
| 41 | }; |
| 42 | struct sock_fprog prog; |
| 43 | prog.len = (unsigned short)(sizeof(filter)/sizeof(filter[0])); |
| 44 | prog.filter = filter; |
| 45 | |
| 46 | int res = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); |
| 47 | if (res != 0) { |
| 48 | fprintf(stderr, "PR_SET_SECCOMP unsupported!\n"); |
| 49 | } |
| 50 | corrupt(); |
| 51 | // CHECK: AddressSanitizer |
| 52 | // CHECK-NOT: reading executable name failed |
| 53 | return 0; |
| 54 | } |