This commit adds a new attribute to syzkaller targets that tells
syzkaller how to invoke the syz-executor command.
Some systems, like Fuchsia, are now building syz-executor as part of the
build, and there is no need to copy it over, or to run it from `/tmp`.
In fact, that might stop working at some time in the future in Fuchsia.
All places that used to copy syz-executor into the target machine will
now check for the SyzExecutorCmd flag, and won't copy it if the flag is
set.
For extractProgSingle() lastEntries are already reversed, so no need to
call reverseEntries().
Also for extractProgBisect() there's no point in reversing the entries,
as the idea is to try connecting multiple programs in chronological order.
Leak checking support was half done and did not really work.
This is heavy-lifting to make it work.
1. Move leak/fault setup into executor.
pkg/host was a wrong place for them because we need then in C repros too.
The pkg/host periodic callback functionality did not work too,
we need it in executor so that we can reuse it in C repros too.
Remove setup/callback functions in pkg/host entirely.
2. Do leak setup/checking in C repros.
The way leak checking is invoked is slightly different from fuzzer,
but much better then no support at all.
At least the checking code is shared.
3. Add Leak option to pkg/csource and -leak flag to syz-prog2c.
4. Don't enalbe leak checking in fuzzer while we are triaging initial corpus.
It's toooo slow.
5. Fix pkg/repro to do something more sane for leak bugs.
Few other minor fixes here and there.
We duplicated the no output timeout in the repro package,
and it got out of sync. It's not 3 mins now, but 5 mins.
Remove the duplication and fix this.
Limit the amount of bisection chunks to 8. Going over this value probably
means that we are bisection a flaky crash, and continuing bisection would
just take a lot of time and likely produce no result.
Instead of always closing open fds (number 3 to 30) after each program,
add an options called EnableCloseFds. It can be passed to syz-execprog,
syz-prog2c and syz-stress via the -enable and -disable flags. Set the
default value to true. Also minimize C repros over it, except for when
repeat is enabled.
Final reproducers are crafty. Sometimes they just stop working.
In that case the detailed listings of the programs executed by syz-repro
are very helpful. Let's print them at the loglevel 3.
Running bisection using an older repro failed with:
<stdin>: In function ‘syz_mount_image.constprop’:
<stdin>:298:3: error: argument 1 null where non-null expected [-Werror=nonnull]
In file included from <stdin>:26:0:
/usr/include/x86_64-linux-gnu/sys/stat.h:320:12: note: in a call to function ‘mkdir’ declared here
extern int mkdir (const char *__path, __mode_t __mode)
Let's be safe and ignore warnings during repro/bisect.
Everything that runs during tests still has all warnings.
Update #501
This change makes all syz-execprog, syz-prog2c and syz-stress accept
-enable and -disable flags to enable or disable additional features
(tun, net_dev, net_reset, cgroups and binfmt_misc) instead of having
a separate flag for each of them.
The default (without any flags) behavior isn't changed: syz-execprog
and syz-stress enabled all the features (provided the runtime supports
them) and syz-prog2c disables all of them.
Currently we only support canExit flag.
However there are actually 3 separate conditions:
- program can exit normally
- program can timeout (e.g. fuzzer test or runtest can't)
- program can exit with error (e.g. C test can)
Allow to specify these 3 conditions separately.
mgrconfig was used only by syz-manager initially,
but now it's used by a dozen of packages and it's
weird to import from under a binary dir.
pkg/ is much more reasonable dir for a widely used
helper package.
Make as much code as possible shared between all OSes.
In particular main is now common across all OSes.
Make more code shared between executor and csource
(in particular, loop function and threaded execution logic).
Also make loop and threaded logic shared across all OSes.
Make more posix/unix code shared across OSes
(e.g. signal handling, pthread creation, etc).
Plus other changes along similar lines.
Also support test OS in executor (based on portable posix)
and add 4 arches that cover all execution modes
(fork server/no fork server, shmem/no shmem).
This change paves way for testing of executor code
and allows to preserve consistency across OSes and executor/csource.
Only akaros needs OS, because the rest assume host OS.
But speciying OS for all OSes breaks patch testing on syzbot
because old execprog does not have os flag.
Provide stats and logs for failed repro and save it in manager.
In particular log is useful for failed repros,
currently there is no visibility into why bugs
failed to reproduce.
Currently getting a complete report requires a complex,
multi-step dance (including getting information that
external users are not interested in -- guilty file).
Simplify interface down to 2 functions: Parse and Symbolize.
Parse does what it did before, Symbolize symbolizes report
and fills in maintainers. This simplifies both implementations
of Reporter interface and all users of the interface.
Potentially we could get this down to 1 function Parse
that does everything. However, (1) Symbolize can fail,
while Parse cannot, (2) usually we want to ignore (log)
Symbolize errors, but otherwise proceed with the report,
(3) repro does not need symbolization for all but the
last report.
Whole raw output is indivisble part of Report,
currently we always pass Output separately along with Report.
Make Output a Report field.
Then, put whole Report into manager Crash and repro context and Result.
There is little point in passing Report as aa bunch of separate fields.
This allows callers to get access to Report.Corrupted.
Better than adding 6-th return value and will allow
to pipe other report properties if necessary.
We currently have several names for crash attributes, which is disturbing.
E.g. crash title is called "Title" or "Desc". Name them consistently.
Title - single line bug identity.
Report - whole crash text.
Log - whole fuzzer/kernel output.
syz-execprog doesn't utilize info about fault injections from a prog log.
Since syz-execprog is used by the repro package to reproduce crashes,
crashes caused by fault injections might not reproduce.
If kernel or syzkaller binaries are rebuilt when manager uses them,
nothing good will happen. Manager can start mixing coverage from
old and new kernels, or crash on unknown syscalls.
Now each prog function accepts the desired target explicitly.
No global, implicit state involved.
This is much cleaner and allows cross-OS/arch testing, etc.
