In that case it is very likely that there will be a tag mismatch anyway.
We handle the case that the pointer belongs to neither of the allocators
by getting a nullptr from allocator.GetBlockBegin.
Reviewed By: hctim, eugenis
Differential Revision: https://reviews.llvm.org/D108383
Fixes a regression when the allocator is disabled, and a dirty
allocation is re-used. This only occurs when the allocator is disabled,
so a test-only fix, but still necessary.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D108650
In that case it is very likely that there will be a tag mismatch anyway.
We handle the case that the pointer belongs to neither of the allocators
by getting a nullptr from allocator.GetBlockBegin.
Reviewed By: hctim, eugenis
Differential Revision: https://reviews.llvm.org/D108383
The shadow for a short granule is stored in the last byte of the
granule. Currently, if there's a tail-overwrite report (a
buffer-overflow-write in uninstrumented code), we report the shadow byte
as a mismatch against the magic.
Fix this bug by slapping the shadow into the expected value. This also
makes sure that if the uninstrumented WRITE does clobber the shadow
byte, it reports the shadow was actually clobbered as well.
Reviewed By: eugenis, fmayer
Differential Revision: https://reviews.llvm.org/D107938
Before this change we were locking the StackDepot in the fork()
interceptor. This results in a deadlock when allocator functions are
used in a pthread_atfork() callback.
Instead, set up a pthread_atfork() callback at init that locks/unlocks
both StackDepot and the allocator. Since our callback is set up very
early, the pre-fork callback is executed late, and both post-fork ones
are executed early, which works perfect for us.
Differential Revision: https://reviews.llvm.org/D108063
D104248 moved the call to GetThreadStackAndTls to before the
initialization of the ring buffer TLS slot. As a result, if libc
is instrumented we crash in pthread_getattr_np which is called from
__sanitizer::GetThreadStackTopAndBottom.
Fix the problem by moving the stack ring buffer initialization before
the call to InitStackAndTls.
Differential Revision: https://reviews.llvm.org/D108184
Enable -Wformat in sanitizer_common now that it's
cleaned up from existing warnings.
But disable it in all sanitizers for now since
they are not cleaned up yet, but inherit sanitizer_common CFLAGS.
Depends on D107980.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D107981
Found by an Android toolchain upgrade, inherited module constructors
(like init_have_lse_atomics from the builtins) can sneak into the hwasan
runtime. If these inherited constructors call hwasanified libc
functions, then the HWASan runtime isn't setup enough, and the code
crashes.
Mark the initialized as a high-priority initializer to fix this.
Reviewed By: pcc, yabinc
Differential Revision: https://reviews.llvm.org/D107391
This will just be a call into __sanitizer_fill_shadow defined in the fuchsia source tree. This depends on D105663.
Differential Revision: https://reviews.llvm.org/D105664
This is empty for now, but we will add a check that TBI is enabled once the
tagged pointer ABI for zircon is finalized. This depends on D105667.
Differential Revision: https://reviews.llvm.org/D105668
The current (default) line length is 80 columns.
That's based on old hardware and historical conventions.
There are no existent reasons to keep line length that small,
especially provided that our coding style uses quite lengthy
identifiers. The Linux kernel recently switched to 100,
let's start with 100 as well.
This change intentionally does not re-format code.
Re-formatting is intended to happen incrementally,
or on dir-by-dir basis separately.
Reviewed By: vitalybuka, melver, MaskRay
Differential Revision: https://reviews.llvm.org/D106436
This moves logic for setting kAliasRegionStart into hwasan_allocator.cpp
so other platforms that do not support aliasing mode will not need to define
kAliasRegionStart.
Differential Revision: https://reviews.llvm.org/D105725
Based on comments in D91466, we can make the current implementation
linux-speciic. The fuchsia implementation will just be a call to
`__sanitizer_fill_shadow`.
Differential Revision: https://reviews.llvm.org/D105663
The new name is something less linux-y and more platform generic. Once we
finalize the tagged pointer ABI in zircon, we will do the appropriate check
for fuchsia to see that TBI is enabled.
Differential Revision: https://reviews.llvm.org/D105667
This contains all the definitions required by hwasan for the fuchsia
implementation and can be landed independently from the remaining parts of D91466.
Differential Revision: https://reviews.llvm.org/D103936
This disables use of hwasan interceptors which we do not use on Fuchsia. This
explicitly sets the macro for defining the hwasan versions of new/delete.
Differential Revision: https://reviews.llvm.org/D103544
This patch splits up hwasan thread creation between `__sanitizer_before_thread_create_hook`,
`__sanitizer_thread_create_hook`, and `__sanitizer_thread_start_hook`.
The linux implementation creates the hwasan thread object inside the
new thread. On Fuchsia, we know the stack bounds before thread creation,
so we can initialize part of the thread object in `__sanitizer_before_thread_create_hook`,
then initialize the stack ring buffer in `__sanitizer_thread_start_hook`
once we enter the thread.
Differential Revision: https://reviews.llvm.org/D104085
We would find an address with matching tag, only to discover in
ShowCandidate that it's very far away from [stack].
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D105197
If the fault address is at the boundary of memory regions, this could
cause us to segfault otherwise.
Ran test with old compiler_rt to make sure it fails.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D105032
Users can call HwasanThreadList::GetRingBufferSize rather than RingBufferSize
to prevent having to do the calculation in RingBufferSize. This will be useful
for Fuchsia where we plan to initialize the stack ring buffer separately from
the rest of thread initialization.
Differential Revision: https://reviews.llvm.org/D104823
A heap or global buffer that is far away from the faulting address is
unlikely to be the cause, especially if there is a potential
use-after-free as well, so we want to show it after the other
causes.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D104781
Similar to InitOptions in asan, we can use this optional struct for
initializing some members thread objects before they are created. On
linux, this is unused and can remain undefined. On fuchsia, this will
just be the stack bounds.
Differential Revision: https://reviews.llvm.org/D104553
Once D104553 lands, CreateCurrentThread will be able to accept optional
parameters for initializing the hwasan thread object. On fuchsia, we can get
stack info in the platform-specific InitThreads and pass it through
CreateCurrentThread. On linux, this is a no-op.
Differential Revision: https://reviews.llvm.org/D104561
Explain what the given stack trace means before showing it, rather than
only in the paragraph at the end.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D104523
This allows for other implementations to define their own version of `Thread::Init`.
This will be the case for Fuchsia where much of the thread initialization can be
broken up between different thread hooks (`__sanitizer_before_thread_create_hook`,
`__sanitizer_thread_create_hook`, `__sanitizer_thread_start_hook`). Namely, setting
up the heap ring buffer and stack info and can be setup before thread creation.
The stack ring buffer can also be setup before thread creation, but storing it into
`__hwasan_tls` can only be done on the thread start hook since it's only then we
can access `__hwasan_tls` for that thread correctly.
Differential Revision: https://reviews.llvm.org/D104248
The default callback instrumentation in x86 LAM mode uses ASLR bits
to randomly choose a tag, and thus has a 1/64 chance of choosing a
stack tag of 0, causing stack tests to fail intermittently. By using
__hwasan_generate_tag to pick tags, we guarantee non-zero tags and
eliminate the test flakiness.
aarch64 doesn't seem to have this problem using thread-local addresses
to pick tags, so perhaps we can remove this workaround once we implement
a similar mechanism for LAM.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D104470
This is to fix build on Android. And we don't want to intercept more new/delete operators on Android.
Differential Revision: https://reviews.llvm.org/D104313
Before: ADDR is located -320 bytes to the right of 1072-byte region
After: ADDR is located 752 bytes inside 1072-byte region
Reviewed By: eugenis, walli99
Differential Revision: https://reviews.llvm.org/D104412
Short granule tags as poison cause a UaF to read the referenced
memory to retrieve the tag, and means we do not detect the UaF
if the last granule's tag is still around.
This only increases the change of not catching a UaF from
0.39 % (1 / 256) to 0.42 % (1 / (256 - 17)).
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D104304
