The current memcg container seems to lead to lots of hangs/stalls.
Presumably the problem is with oom_score_adj and KASAN.
Executor process tree eats all memory and then the leaf process is killed
but the memory is not returned to memcg due to KASAN quarantine;
and the parent processes are protected from killing with oom_score_adj=-1000.
As the result the kernel locks up.
1. Don't use oom_score_adj=-1000. Instead bump leaf process score to 1000 (kill always).
2. Increase size of memcg to be larger than expected KASAN quarantine size.
Rewind kmemleak fd before reading it second time,
otherwise we will read truncated reports.
Auto-learn what leak reports we've already seen
and ignore them in future. This is required because
there are some false positives and some fire too frequently.
So now we will hit each leak only once per manager run,
but we still will try to reproduce them.
This sucks a lot, but ebtables.h is now broken too on Debian 4.17:
ebtables.h: In function ‘ebt_entry_target* ebt_get_target(ebt_entry*)’:
ebtables.h:197:19: error: invalid conversion from ‘void*’ to ‘ebt_entry_target*’
Improve go-fuzz fuzzer function and fix few new bugs it finds:
1. Panic in linux parser (bad).
2. Akaros can report empty rep.Report.
3. Fuchsia can return empty rep.Report.
Sometimes race conditions are reproduced by syz-execprog and are not
reproduced by the programs generated with syz-prog2c. In such cases
it's very helpful to know when exactly the fuzzing syscalls are executed.
Unfortunately, adding timestamps to the output of the original 'debug'
mode doesn't work. This mode provides very verbose output, which slows
down executor and breaks the repro.
So let's make the executor debug output less verbose and add
the timestamps.
Signed-off-by: Alexander Popov <alex.popov@linux.com>
On OpenBSD, nm(1) does not support the `-S' option.
The order of symbols from nm(1) varies between platforms, therefore rework the
test case to cope with that.
Fixes#723
Move debug_dump_data back to executor.cc.
debug_dump_data in common_linux.h does not play well
with pkg/csource debug stripping logic. It strips a large
random piece of code since it thinks debug_dump_data
definition is actually debug_dump_data call site.
Currently we have a global fixed set of sandboxes,
which makes it hard to add new OS-specific ones
(all OSes need to updated to say that they don't
support this sandbox).
Let it each OS say what sandboxes it supports instead.
executor: add support for android_untrusted_app sandbox
This adds a new sandbox type, 'android_untrusted_app', which restricts
syz-executor to the privileges which are available to third-party applications,
e.g. those installed from the Google Play store.
In particular, this uses the UID space reserved for applications (instead of
the 'setuid' sandbox, which uses the traditional 'nobody' user / 65534)
as well as a set of groups which the Android-specific kernels are aware of,
and finally ensures that the SELinux context is set appropriately.
Dependencies on libselinux are avoided by manually implementing the few
functions that are needed to change the context of the current process,
and arbitrary files. The underlying mechanisms are relatively simple.
Fixesgoogle/syzkaller#643
Test: make presubmit
Bug: http://b/112900774
For vmm we need a pre-created image.
So if one is provided in the userspace dir,
copy it to output. This should be enough
to get vmm working.
Update #712
We currently have this list in multiple places (somewhat diverged).
Specify this "overcommit" property in VM implementations.
In particular, we also want to allow overcommit for "vmm" type.
Update #712
After generating syscall description for fidl files using fidlgen, prune
all unused structs using the exact same mechanism used by the compiler's
check for unused structs. This allows the FIDL compiler to support
modular compilation; it does not need to have global knowledge of
whether each struct is used or not.
During rcu stalls and cpu lockups kernel loops in some part of code,
usually across several functions. When the stall is detected, traceback
points to a random stack within the looping code. We generally take
the top function in the stack (with few exceptions) as the bug identity.
As the result stalls with the same root would produce multiple reports
in different functions, which is bad.
Instead we identify a representative function deeper in the stack.
For most syscalls it can be the syscall entry function (e.g. SyS_timer_create).
However, for highly discriminated functions syscalls like ioctl/read/write/connect
we take the previous function (e.g. for connect the one that points to exact
protocol, or for ioctl the one that is related to the device).
Fixes#710
Currently we choose block device to use (nbd/loop) based on SYZ_VM_TYPE.
Strictly saying these things are orthogonal.
losetup is broken on Ubuntu. qemu-nbd is broken on Debian.
Try to auto-detect what will work based on uname.
Add simple fuchsia program, the one that is run during image testing.
Fix csource errno printing for fuchsia.
Fix creation of executable files (chmod is not implemented on fuchsia).
Check that we get signal/coverage from all syscalls.
Upstream "selinux: fix mounting of cgroup2 under older policies"
commit fixes mounting of cgroup2 under wheezy selinux policy.
So don't disable selinux on start.
Create separate cmdline arguments that enable selinux and apparmor.
If we build fuchsia with asan, syz-executor binary fails to run with:
$ /tmp/syz-executor
[00041.656] 01128.01275> dlsvc: could not open 'libc++.so.2'
[00041.656] 06074.06088> Error loading shared library libc++.so.2: ZX_ERR_NOT_FOUND (needed by
[00041.656] 06074.06088> /tmp/syz-executor
[00041.656] 06074.06088> )
[00041.656] 01128.01275> dlsvc: could not open 'libc++abi.so.1'
[00041.656] 06074.06088> Error loading shared library libc++abi.so.1: ZX_ERR_NOT_FOUND (needed by
[00041.656] 06074.06088> /tmp/syz-executor
[00041.656] 06074.06088> )
[00041.663] 01128.01275> dlsvc: could not open 'libunwind.so.1'
[00041.663] 06074.06088> Error loading shared library libunwind.so.1: ZX_ERR_NOT_FOUND (needed by
[00041.663] 06074.06088> /tmp/syz-executor
[00041.663] 06074.06088> )
Disable asan until we figure out how to fix this.
