| // TODO: remove need for this option: |
| /* { dg-additional-options "-fanalyzer-checker=taint" } */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| struct foo |
| { |
| ssize_t offset; |
| }; |
| |
| char *p; |
| |
| char test_1(FILE *f) |
| { |
| struct foo tmp; |
| |
| if (1 == fread(&tmp, sizeof(tmp), 1, f)) { /* { dg-message "\\(\[0-9\]+\\) 'tmp' gets an unchecked value here" "event: tmp gets unchecked value" { xfail *-*-* } } */ |
| /* { dg-message "\\(\[0-9\]+\\) following 'true' branch\\.\\.\\." "event: following true branch" { target *-*-* } .-1 } */ |
| /* BUG: the following array lookup trusts that the input data's index is |
| in the range 0 <= i < 256; otherwise it's accessing the stack */ |
| *(p + tmp.offset) = 42; // { dg-warning "use of attacker-controlled value 'tmp.offset' as offset without bounds checking" "warning" } */ |
| /* { dg-message "\\(\[0-9\]+\\) \\.\\.\\.to here" "event: to here" { target *-*-* } .-1 } */ |
| /* { dg-message "\\(\[0-9\]+\\) 'tmp.offset' has an unchecked value here \\(from 'tmp'\\)" "event: tmp.offset has an unchecked value" { xfail *-*-* } .-2 } */ |
| /* { dg-message "\\(\[0-9\]+\\) use of attacker-controlled value 'tmp.offset' as offset without bounds checking" "final event" { target *-*-* } .-3 } */ |
| |
| // TOOD: better messages for state changes |
| } |
| return 0; |
| } |
| |
| char test_2(struct foo *f) |
| { |
| /* not a bug: the data is not known to be tainted: */ |
| *(p + f->offset) = 42; |
| } |
| |
| char test_3(FILE *f) |
| { |
| struct foo tmp; |
| |
| if (1 == fread(&tmp, sizeof(tmp), 1, f)) { |
| if (tmp.offset >= 0 && tmp.offset < 256) { |
| /* not a bug: the access is guarded by upper and lower bounds: */ |
| *(p + tmp.offset) = 42; |
| } |
| } |
| return 0; |
| } |
| |
| char test_4(FILE *f) |
| { |
| struct foo tmp; |
| |
| if (1 == fread(&tmp, sizeof(tmp), 1, f)) { |
| if (tmp.offset >= 0) { /* { dg-message "'tmp.offset' has an unchecked value here \\(from 'tmp'\\)" "event: tmp.offset has an unchecked value" { xfail *-*-* } } */ |
| /* { dg-message "'tmp.offset' has its lower bound checked here" "event: lower bound checked" { xfail *-*-* } .-1 } */ |
| *(p + tmp.offset) = 42; /* { dg-warning "use of attacker-controlled value 'tmp.offset' as offset without upper-bounds checking" "warning" } */ |
| } |
| } |
| return 0; |
| } |
| |
| char test_5(FILE *f) |
| { |
| struct foo tmp; |
| |
| if (1 == fread(&tmp, sizeof(tmp), 1, f)) { |
| if (tmp.offset < 256) { /* { dg-message "'tmp.offset' has an unchecked value here \\(from 'tmp'\\)" "event: tmp.offset has an unchecked value" { xfail *-*-* } } */ |
| /* { dg-message "'tmp.offset' has its upper bound checked here" "event: upper bound checked" { xfail *-*-* } .-1 } */ |
| *(p + tmp.offset) = 42; /* { dg-warning "use of attacker-controlled value 'tmp.offset' as offset without lower-bounds checking" "warning" } */ |
| } |
| } |
| return 0; |
| } |
| |
| /* unsigned types have a natural lower bound of 0 */ |
| struct bar |
| { |
| unsigned int offset; |
| char buf[256]; |
| }; |
| |
| char test_6(FILE *f) |
| { |
| struct bar tmp; |
| |
| if (1 == fread(&tmp, sizeof(tmp), 1, f)) { |
| *(p + tmp.offset) = 42; /* { dg-warning "use of attacker-controlled value 'tmp.offset' as offset without upper-bounds checking" } */ |
| } |
| return 0; |
| } |
| |
| char test_7(FILE *f) |
| { |
| struct bar tmp; |
| |
| if (1 == fread(&tmp, sizeof(tmp), 1, f)) { |
| if (tmp.offset >= 0) { |
| *(p + tmp.offset) = 42; /* { dg-warning "use of attacker-controlled value 'tmp.offset' as offset without upper-bounds checking" } */ |
| } |
| } |
| return 0; |
| } |
| |
| char test_8(FILE *f) |
| { |
| struct bar tmp; |
| |
| if (1 == fread(&tmp, sizeof(tmp), 1, f)) { |
| if (tmp.offset < 256) { |
| /* not a bug: has an upper bound, and an implicit lower bound: */ |
| *(p + tmp.offset) = 42; |
| } |
| } |
| return 0; |
| } |
| |
| char test_9(FILE *f) |
| { |
| struct foo tmp; |
| |
| if (1 == fread(&tmp, sizeof(tmp), 1, f)) { |
| if (tmp.offset == 42) { |
| /* not a bug: tmp.offset compared against a specific value: */ |
| *(p + tmp.offset) = 42; /* { dg-bogus "tainted" "" { xfail *-*-* } } */ |
| // TODO: xfail |
| } |
| } |
| return 0; |
| } |