diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/Changelog.md | 17 | ||||
| -rw-r--r-- | docs/PATCHES.md | 43 | ||||
| -rw-r--r-- | docs/custom_mutators.md | 2 | ||||
| -rw-r--r-- | docs/env_variables.md | 64 | ||||
| -rw-r--r-- | docs/notes_for_asan.md | 7 | ||||
| -rw-r--r-- | docs/perf_tips.md | 3 |
6 files changed, 60 insertions, 76 deletions
diff --git a/docs/Changelog.md b/docs/Changelog.md index 5b7d6ab6..24877f9a 100644 --- a/docs/Changelog.md +++ b/docs/Changelog.md @@ -8,6 +8,23 @@ Want to stay in the loop on major new features? Join our mailing list by sending a mail to <afl-users+subscribe@googlegroups.com>. +### Version ++3.13a (development) + - frida_mode - new mode that uses frida to fuzz binary-only targets, + thanks to @WorksButNotTested! + - create a fuzzing dictionary with the help of CodeQL thanks to + @microsvuln! see utils/autodict_ql + - afl-fuzz: + - added patch by @realmadsci to support @@ as part of command line + options, e.g. `afl-fuzz ... -- ./target --infile=@@` + - add recording of previous fuzz attempts for persistent mode + to allow replay of non-reproducable crashes, see + AFL_PERSISTENT_RECORD in config.h and docs/envs.h + - default cmplog level (-l) is now 2, better efficiency. + - ensure one fuzzer sync per cycle + - afl-cc: + - Leak Sanitizer support (AFL_USE_LSAN) added by Joshua Rogers, thanks! + - Removed InsTrim instrumentation as it is not as good as PCGUARD + ### Version ++3.12c (release) - afl-fuzz: - added AFL_TARGET_ENV variable to pass extra env vars to the target diff --git a/docs/PATCHES.md b/docs/PATCHES.md deleted file mode 100644 index b2cff43a..00000000 --- a/docs/PATCHES.md +++ /dev/null @@ -1,43 +0,0 @@ -# Applied Patches - -The following patches from https://github.com/vanhauser-thc/afl-patches -have been installed or not installed: - - -## INSTALLED -``` -afl-llvm-fix.diff by kcwu(at)csie(dot)org -afl-sort-all_uniq-fix.diff by legarrec(dot)vincent(at)gmail(dot)com -laf-intel.diff by heiko(dot)eissfeldt(at)hexco(dot)de -afl-llvm-optimize.diff by mh(at)mh-sec(dot)de -afl-fuzz-tmpdir.diff by mh(at)mh-sec(dot)de -afl-fuzz-79x24.diff by heiko(dot)eissfeldt(at)hexco(dot)de -afl-fuzz-fileextensionopt.diff tbd -afl-as-AFL_INST_RATIO.diff by legarrec(dot)vincent(at)gmail(dot)com -afl-qemu-ppc64.diff by william(dot)barsse(at)airbus(dot)com -afl-qemu-optimize-entrypoint.diff by mh(at)mh-sec(dot)de -afl-qemu-speed.diff by abiondo on github -afl-qemu-optimize-map.diff by mh(at)mh-sec(dot)de -``` - -+ llvm_mode ngram prev_loc coverage (github.com/adrianherrera/afl-ngram-pass) -+ Custom mutator (native library) (by kyakdan) -+ unicorn_mode (modernized and updated by domenukk) -+ instrim (https://github.com/csienslab/instrim) was integrated -+ MOpt (github.com/puppet-meteor/MOpt-AFL) was imported -+ AFLfast additions (github.com/mboehme/aflfast) were incorporated. -+ Qemu 3.1 upgrade with enhancement patches (github.com/andreafioraldi/afl) -+ Python mutator modules support (github.com/choller/afl) -+ Instrument file list in LLVM mode (github.com/choller/afl) -+ forkserver patch for afl-tmin (github.com/nccgroup/TriforceAFL) - - -## NOT INSTALLED - -``` -afl-fuzz-context_sensitive.diff - changes too much of the behaviour -afl-tmpfs.diff - same as afl-fuzz-tmpdir.diff but more complex -afl-cmin-reduce-dataset.diff - unsure of the impact -afl-llvm-fix2.diff - not needed with the other patches -``` - diff --git a/docs/custom_mutators.md b/docs/custom_mutators.md index 61d711e4..62e01f83 100644 --- a/docs/custom_mutators.md +++ b/docs/custom_mutators.md @@ -89,10 +89,10 @@ def queue_get(filename): def queue_new_entry(filename_new_queue, filename_orig_queue): pass -``` def introspection(): return string +``` ### Custom Mutation diff --git a/docs/env_variables.md b/docs/env_variables.md index 409425f1..8d482e20 100644 --- a/docs/env_variables.md +++ b/docs/env_variables.md @@ -55,7 +55,7 @@ make fairly broad use of environmental variables instead: overridden. - Setting `AFL_USE_ASAN` automatically enables ASAN, provided that your - compiler supports that. Note that fuzzing with ASAN is mildly challenging + compiler supports it. Note that fuzzing with ASAN is mildly challenging - see [notes_for_asan.md](notes_for_asan.md). (You can also enable MSAN via `AFL_USE_MSAN`; ASAN and MSAN come with the @@ -64,6 +64,13 @@ make fairly broad use of environmental variables instead: there is the Control Flow Integrity sanitizer that can be activated by `AFL_USE_CFISAN=1`) + - Setting `AFL_USE_LSAN` automatically enables Leak-Sanitizer, provided + that your compiler supports it. To perform a leak check within your + program at a certain point (such as at the end of an __AFL_LOOP), + you can run the macro __AFL_LEAK_CHECK(); which will cause + an abort if any memory is leaked (you can combine this with the + LSAN_OPTIONS=suppressions option to supress some known leaks). + - Setting `AFL_CC`, `AFL_CXX`, and `AFL_AS` lets you use alternate downstream compilation tools, rather than the default 'clang', 'gcc', or 'as' binaries in your `$PATH`. @@ -130,16 +137,15 @@ Then there are a few specific features that are only available in instrumentatio PCGUARD - our own pcgard based instrumentation (default) NATIVE - clang's original pcguard based instrumentation CLASSIC - classic AFL (map[cur_loc ^ prev_loc >> 1]++) (default) - CFG - InsTrim instrumentation (see below) LTO - LTO instrumentation (see below) CTX - context sensitive instrumentation (see below) NGRAM-x - deeper previous location coverage (from NGRAM-2 up to NGRAM-16) GCC - outdated gcc instrumentation CLANG - outdated clang instrumentation - In CLASSIC (default) and CFG/INSTRIM you can also specify CTX and/or - NGRAM, seperate the options with a comma "," then, e.g.: - `AFL_LLVM_INSTRUMENT=CFG,CTX,NGRAM-4` - Not that this is a good idea to use both CTX and NGRAM :) + In CLASSIC you can also specify CTX and/or NGRAM, seperate the options + with a comma "," then, e.g.: + `AFL_LLVM_INSTRUMENT=CLASSIC,CTX,NGRAM-4` + Note that this is actually not a good idea to use both CTX and NGRAM :) ### LTO @@ -173,24 +179,6 @@ Then there are a few specific features that are only available in instrumentatio See [instrumentation/README.lto.md](../instrumentation/README.lto.md) for more information. -### INSTRIM - - This feature increases the speed by ~15% without any disadvantages to the - classic instrumentation. - - Note that there is also an LTO version (if you have llvm 11 or higher) - - that is the best instrumentation we have. Use `afl-clang-lto` to activate. - The InsTrim LTO version additionally has all the options and features of - LTO (see above). - - - Setting `AFL_LLVM_INSTRIM` or `AFL_LLVM_INSTRUMENT=CFG` activates this mode - - - Setting `AFL_LLVM_INSTRIM_LOOPHEAD=1` expands on INSTRIM to optimize loops. - afl-fuzz will only be able to see the path the loop took, but not how - many times it was called (unless it is a complex loop). - - See [instrumentation/README.instrim.md](../instrumentation/README.instrim.md) - ### NGRAM - Setting `AFL_LLVM_NGRAM_SIZE` or `AFL_LLVM_INSTRUMENT=NGRAM-{value}` @@ -391,7 +379,8 @@ checks or alter some of the more exotic semantics of the tool: may complain of high load prematurely, especially on systems with low core counts. To avoid the alarming red color, you can set `AFL_NO_CPU_RED`. - - In QEMU mode (-Q), `AFL_PATH` will be searched for afl-qemu-trace. + - In QEMU mode (-Q), Unicorn mode (-U) and Frida mode (-O), `AFL_PATH` will + be searched for afl-qemu-trace. - In QEMU mode (-Q), setting `AFL_QEMU_CUSTOM_BIN` cause afl-fuzz to skip prepending `afl-qemu-trace` to your command line. Use this if you wish to use a @@ -424,6 +413,16 @@ checks or alter some of the more exotic semantics of the tool: - Setting `AFL_FORCE_UI` will force painting the UI on the screen even if no valid terminal was detected (for virtual consoles) + - If you are using persistent mode (you should, see [instrumentation/README.persistent_mode.md](instrumentation/README.persistent_mode.md)) + some targets keep inherent state due which a detected crash testcase does + not crash the target again when the testcase is given. To be able to still + re-trigger these crashes you can use the `AFL_PERSISTENT_RECORD` variable + with a value of how many previous fuzz cases to keep prio a crash. + if set to e.g. 10, then the 9 previous inputs are written to + out/default/crashes as RECORD:000000,cnt:000000 to RECORD:000000,cnt:000008 + and RECORD:000000,cnt:000009 being the crash case. + NOTE: This option needs to be enabled in config.h first! + - If you are Jakub, you may need `AFL_I_DONT_CARE_ABOUT_MISSING_CRASHES`. Others need not apply, unless they also want to disable the `/proc/sys/kernel/core_pattern` check. @@ -614,7 +613,7 @@ optimal values if not already present in the environment: override this by setting `LD_BIND_LAZY` beforehand, but it is almost certainly pointless. - - By default, `ASAN_OPTIONS` are set to: + - By default, `ASAN_OPTIONS` are set to (among others): ``` abort_on_error=1 detect_leaks=0 @@ -635,7 +634,14 @@ optimal values if not already present in the environment: msan_track_origins=0 allocator_may_return_null=1 ``` - Be sure to include the first one when customizing anything, since some - MSAN versions don't call `abort()` on error, and we need a way to detect - faults. + - Similarly, the default `LSAN_OPTIONS` are set to: +``` + exit_code=23 + fast_unwind_on_malloc=0 + symbolize=0 + print_suppressions=0 +``` + Be sure to include the first ones for LSAN and MSAN when customizing + anything, since some MSAN and LSAN versions don't call `abort()` on + error, and we need a way to detect faults. diff --git a/docs/notes_for_asan.md b/docs/notes_for_asan.md index 2b3bc028..f55aeaf2 100644 --- a/docs/notes_for_asan.md +++ b/docs/notes_for_asan.md @@ -28,6 +28,13 @@ Note that ASAN is incompatible with -static, so be mindful of that. (You can also use AFL_USE_MSAN=1 to enable MSAN instead.) +When compiling with AFL_USE_LSAN, the leak sanitizer will normally run +when the program exits. In order to utilize this check at different times, +such as at the end of a loop, you may use the macro __AFL_LEAK_CHECK();. +This macro will report a crash in afl-fuzz if any memory is left leaking +at this stage. You can also use LSAN_OPTIONS and a supressions file +for more fine-tuned checking, however make sure you keep exitcode=23. + NOTE: if you run several secondary instances, only one should run the target compiled with ASAN (and UBSAN, CFISAN), the others should run the target with no sanitizers compiled in. diff --git a/docs/perf_tips.md b/docs/perf_tips.md index fbcb4d8d..c5968206 100644 --- a/docs/perf_tips.md +++ b/docs/perf_tips.md @@ -69,9 +69,6 @@ If you are only interested in specific parts of the code being fuzzed, you can instrument_files the files that are actually relevant. This improves the speed and accuracy of afl. See instrumentation/README.instrument_list.md -Also use the InsTrim mode on larger binaries, this improves performance and -coverage a lot. - ## 4. Profile and optimize the binary Check for any parameters or settings that obviously improve performance. For |