| 1 |
commit: 67f3ba64c91b5e1ac9fbbd0bc039fb8ca653cae1 |
| 2 |
Author: Mike Frysinger <vapier <AT> gentoo <DOT> org> |
| 3 |
AuthorDate: Sat Mar 4 23:46:33 2017 +0000 |
| 4 |
Commit: Mike Frysinger <vapier <AT> gentoo <DOT> org> |
| 5 |
CommitDate: Fri Apr 16 19:22:01 2021 +0000 |
| 6 |
URL: https://gitweb.gentoo.org/proj/pax-utils.git/commit/?id=67f3ba64 |
| 7 |
|
| 8 |
dumpelf: add libFuzzer support |
| 9 |
|
| 10 |
Now you can build dumpelf with libFuzzer and beat the hell out of it. |
| 11 |
|
| 12 |
Signed-off-by: Mike Frysinger <vapier <AT> gentoo.org> |
| 13 |
|
| 14 |
Makefile | 2 +- |
| 15 |
dumpelf.c | 43 ++++++++++++++++++++++++++++++++++--------- |
| 16 |
2 files changed, 35 insertions(+), 10 deletions(-) |
| 17 |
|
| 18 |
diff --git a/Makefile b/Makefile |
| 19 |
index 8e7b183..9a2c07c 100644 |
| 20 |
--- a/Makefile |
| 21 |
+++ b/Makefile |
| 22 |
@@ -115,7 +115,7 @@ afl-fuzz: clean |
| 23 |
"afl-fuzz -t 100 -i tests/fuzz/small/ -o findings/ ./scanelf -s '*' -axetrnibSDIYZB @@" |
| 24 |
|
| 25 |
# Not all objects support libfuzzer. |
| 26 |
-LIBFUZZER_TARGETS = |
| 27 |
+LIBFUZZER_TARGETS = dumpelf |
| 28 |
LIBFUZZER_FLAGS = \ |
| 29 |
-fsanitize=fuzzer \ |
| 30 |
-fsanitize-coverage=edge |
| 31 |
|
| 32 |
diff --git a/dumpelf.c b/dumpelf.c |
| 33 |
index bc634f0..342251f 100644 |
| 34 |
--- a/dumpelf.c |
| 35 |
+++ b/dumpelf.c |
| 36 |
@@ -11,7 +11,6 @@ const char argv0[] = "dumpelf"; |
| 37 |
#include "paxinc.h" |
| 38 |
|
| 39 |
/* prototypes */ |
| 40 |
-static void dumpelf(const char *filename, size_t file_cnt); |
| 41 |
static void dump_ehdr(elfobj *elf, const void *ehdr); |
| 42 |
static void dump_phdr(elfobj *elf, const void *phdr, size_t phdr_cnt); |
| 43 |
static void dump_shdr(elfobj *elf, const void *shdr, size_t shdr_cnt, const char *section_name); |
| 44 |
@@ -31,15 +30,10 @@ static char be_verbose = 0; |
| 45 |
static const void *phdr_dynamic_void; |
| 46 |
|
| 47 |
/* dump all internal elf info */ |
| 48 |
-static void dumpelf(const char *filename, size_t file_cnt) |
| 49 |
+static void dumpelf(elfobj *elf, size_t file_cnt) |
| 50 |
{ |
| 51 |
- elfobj *elf; |
| 52 |
size_t i, b; |
| 53 |
|
| 54 |
- /* verify this is real ELF */ |
| 55 |
- if ((elf = readelf(filename)) == NULL) |
| 56 |
- return; |
| 57 |
- |
| 58 |
phdr_dynamic_void = NULL; |
| 59 |
|
| 60 |
printf("#include <elf.h>\n"); |
| 61 |
@@ -50,7 +44,7 @@ static void dumpelf(const char *filename, size_t file_cnt) |
| 62 |
" * ELF dump of '%s'\n" |
| 63 |
" * %ji (0x%jX) bytes\n" |
| 64 |
" */\n\n", |
| 65 |
- filename, elf->len, elf->len); |
| 66 |
+ elf->filename, elf->len, elf->len); |
| 67 |
|
| 68 |
/* setup the struct to namespace this elf */ |
| 69 |
#define MAKE_STRUCT(B) \ |
| 70 |
@@ -148,6 +142,17 @@ static void dumpelf(const char *filename, size_t file_cnt) |
| 71 |
printf(" /* no dynamic tags ! */ "); |
| 72 |
} |
| 73 |
printf("};\n"); |
| 74 |
+} |
| 75 |
+ |
| 76 |
+static void dumpelf_file(const char *filename, size_t file_cnt) |
| 77 |
+{ |
| 78 |
+ elfobj *elf = readelf(filename); |
| 79 |
+ |
| 80 |
+ /* verify this is real ELF */ |
| 81 |
+ if (elf == NULL) |
| 82 |
+ return; |
| 83 |
+ |
| 84 |
+ dumpelf(elf, file_cnt); |
| 85 |
|
| 86 |
/* get out of here */ |
| 87 |
unreadelf(elf); |
| 88 |
@@ -570,10 +575,29 @@ static void parseargs(int argc, char *argv[]) |
| 89 |
size_t file_cnt = 0; |
| 90 |
|
| 91 |
while (optind < argc) |
| 92 |
- dumpelf(argv[optind++], file_cnt++); |
| 93 |
+ dumpelf_file(argv[optind++], file_cnt++); |
| 94 |
} |
| 95 |
} |
| 96 |
|
| 97 |
+#if PAX_UTILS_LIBFUZZ |
| 98 |
+int LLVMFuzzerInitialize(int *argc, char ***argv) |
| 99 |
+{ |
| 100 |
+ (void)argc; |
| 101 |
+ (void)argv; |
| 102 |
+ (void)parseargs; |
| 103 |
+ security_init(false); |
| 104 |
+ return 0; |
| 105 |
+} |
| 106 |
+ |
| 107 |
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) |
| 108 |
+{ |
| 109 |
+ elfobj *elf = readelf_buffer("libFuzzer", data, size); |
| 110 |
+ if (elf == NULL) |
| 111 |
+ return 0; |
| 112 |
+ dumpelf(elf, 0); |
| 113 |
+ return 0; |
| 114 |
+} |
| 115 |
+#else |
| 116 |
int main(int argc, char *argv[]) |
| 117 |
{ |
| 118 |
security_init(false); |
| 119 |
@@ -582,3 +606,4 @@ int main(int argc, char *argv[]) |
| 120 |
parseargs(argc, argv); |
| 121 |
return EXIT_SUCCESS; |
| 122 |
} |
| 123 |
+#endif |
Archives