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 // REQUIRES: shell 7 // UNSUPPORTED: android 8 9 #include <errno.h> 10 #include <stddef.h> 11 #include <stdlib.h> 12 #include <stdio.h> 13 #include <sys/prctl.h> 14 #include <sys/syscall.h> 15 #include <linux/filter.h> 16 #include <linux/seccomp.h> 17 18 #ifndef __NR_readlink 19 # define __NR_readlink __NR_readlinkat 20 #endif 21 22 #define syscall_nr (offsetof(struct seccomp_data, nr)) 23 24 void corrupt() { 25 void *p = malloc(10); 26 free(p); 27 free(p); 28 } 29 30 int main() { 31 prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); 32 33 struct sock_filter filter[] = { 34 /* Grab the system call number */ 35 BPF_STMT(BPF_LD + BPF_W + BPF_ABS, syscall_nr), 36 // If this is __NR_readlink, 37 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, __NR_readlink, 0, 1), 38 // return with EPERM, 39 BPF_STMT(BPF_RET + BPF_K, SECCOMP_RET_ERRNO | EPERM), 40 // otherwise allow the syscall. 41 BPF_STMT(BPF_RET + BPF_K, SECCOMP_RET_ALLOW) 42 }; 43 struct sock_fprog prog; 44 prog.len = (unsigned short)(sizeof(filter)/sizeof(filter[0])); 45 prog.filter = filter; 46 47 int res = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); 48 if (res != 0) { 49 fprintf(stderr, "PR_SET_SECCOMP unsupported!\n"); 50 } 51 corrupt(); 52 // CHECK: AddressSanitizer 53 // CHECK-NOT: reading executable name failed 54 return 0; 55 } 56