Commit Graph

724 Commits (2024120200)

Author SHA1 Message Date
Daniel Micay a7302add63 update outdated branch in README 2024-10-23 06:36:02 -04:00
Daniel Micay b1d9571fec remove trailing whitespace 2024-10-12 03:23:52 -04:00
Daniel Micay e03579253a preserve PROT_MTE when releasing memory 2024-10-12 03:19:16 -04:00
Daniel Micay 9739cb4690 use wrapper for calling memory_map_mte 2024-10-12 03:19:03 -04:00
Daniel Micay aa950244f8 reuse code for memory_map_mte
This drops the separate error message since that doesn't seem useful.
2024-10-12 03:18:36 -04:00
Daniel Micay 6402e2b0d4 reduce probability hint for is_memtag_enabled 2024-10-12 03:17:44 -04:00
Daniel Micay e86192e7fe remove redundant warning switches for Android
Android already enables -Wall and -Wextra in the global soong build
settings.
2024-10-09 19:57:15 -04:00
Julien Voisin 6ce663a8bd Fix -Wimplicit-function-declaration error with gcc 14.
```
malloc_info.c: In function 'leak_memory':
malloc_info.c:12:12: error: implicit declaration of function 'malloc' [-Wimplicit-function-declaration]
   12 |     (void)!malloc(1024 * 1024 * 1024);
      |            ^~~~~~
malloc_info.c:10:1: note: include '<stdlib.h>' or provide a declaration of 'malloc'
    9 | #include "../util.h"
  +++ |+#include <stdlib.h>
   10 |
malloc_info.c:12:12: warning: incompatible implicit declaration of built-in function 'malloc' [-Wbuiltin-declaration-mismatch]
   12 |     (void)!malloc(1024 * 1024 * 1024);
      |            ^~~~~~
```

Taken from https://gitlab.alpinelinux.org/alpine/aports/-/merge_requests/72971/

Co-authored-by: @mio
2024-10-03 23:44:15 -04:00
maade93791 9ca9d2d925 android: use more basic CPU target for memtag
This is required for hardened_malloc to work in microdroid on MTE-enabled devices (currently, 8th
and 9th generation Pixels) since PVMFW only supports ARMv8 cores.

https://android.googlesource.com/platform/packages/modules/Virtualization/+/refs/tags/android-15.0.0_r1/pvmfw/platform.dts#100
2024-09-09 19:22:23 -04:00
Daniel Micay 3f07acfab1 update libdivide to 5.1 2024-08-05 02:25:55 -04:00
Daniel Micay 749640c274 update copyright notice 2024-02-15 02:57:33 -05:00
Dmitry Muhomor 7268189933 mte: use tag 0 for freed slots, stop reserving tag 15 2024-01-23 12:56:54 -05:00
Dmitry Muhomor 3c1f40aff0 amend memory tagging README section
Memory tagging is enabled by default in bionic, but can be disabled at any point.
Memory tagging can't be re-enabled after it's disabled.
2024-01-23 12:56:54 -05:00
Dmitry Muhomor 5fbbdc2ef8 memtag_test: add test for MADV_DONTNEED behavior 2024-01-23 12:56:54 -05:00
Dmitry Muhomor 7d2151e40c mte: remove util.h dependency from arm_mte.h
It's needed for including arm_mte.h into memtag_test.cc
2024-01-23 12:56:54 -05:00
Dmitry Muhomor 4756716904 memtag_test: move SEGV code checks to device-side binary 2024-01-23 12:56:54 -05:00
Daniel Micay a3bf742c3e remove trailing whitespace 2024-01-03 14:44:08 -05:00
Julien Voisin 53a45b4661 Improve a bit the formulation of the MTE documentation 2024-01-03 13:40:42 -05:00
Daniel Micay abe54dba27 update memory tagging documentation 2024-01-03 12:22:56 -05:00
Dmitry Muhomor 365ee6900d android: restore the default SIGABRT handler in fatal_error()
async_safe_fatal() calls abort() at the end, which can be intercepted by a custom SIGABRT handler.

In particular, crashlytics installs such a handler and tries to fork() after catching SIGABRT.

hardened_malloc uses pthread_atfork() to register fork handlers. These handlers try to lock internal
hardened_malloc mutexes. If at least one of those mutexes is already locked, which is usually the
case, thread that called fatai_error() gets deadlocked, while the other threads (if there are any)
continue to run.
2023-12-31 11:21:28 -05:00
Christian Göttsche 7093fdc482 README: add note about AppArmor constraint on Debian 2023-12-14 09:06:32 -05:00
jvoisin 61821b02c8 Clarify a bit why a particular magic number was chosen 2023-11-16 14:25:54 -05:00
Daniel Micay 3c274731ba Revert "use safe_flag for -fstack-clash-protection"
This reverts commit 4171bd164e.
2023-11-14 16:19:33 -05:00
Daniel Micay 4171bd164e use safe_flag for -fstack-clash-protection 2023-11-08 14:21:04 -05:00
jvoisin 352c083f65 Run the testsuite on multiple compiler versions 2023-11-05 17:58:32 -05:00
Dmitry Muhomor 88b3c1acf9 memtag_test: fix sporadic failures of overflow/underflow tests 2023-11-01 17:33:20 -04:00
Daniel Micay f793a3edf6 update README now that MTE is implemented 2023-10-30 14:23:48 -04:00
Dmitry Muhomor fd75fc1ba8 mte: add scudo to CREDITS file 2023-10-30 14:20:53 -04:00
Dmitry Muhomor 72dc236d5f mte: add untag_pointer() variant for const pointers 2023-10-30 14:20:53 -04:00
Dmitry Muhomor be08eeee2d mte: update comment about skipped tag array update in deallocate_small() 2023-10-30 14:20:53 -04:00
Dmitry Muhomor 25f0fe9c69 remove an always-true sizeof(u8) assert 2023-10-30 14:20:53 -04:00
Dmitry Muhomor c75cb4c3f3 mte: refactor tag_and_clear_slab_slot()
Explicitly call is_memtag_enabled() before calling tag_and_clear_slab_slot() to make it clearer that
memory is not zeroed when MTE is disabled.
2023-10-30 14:20:53 -04:00
Dmitry Muhomor b560431c01 mte: note why 0 tag is excluded 2023-10-30 14:20:53 -04:00
Dmitry Muhomor 009f2dad76 mte: note alignment requirements of arm_mte_tag_and_clear_mem() 2023-10-30 14:20:53 -04:00
Dmitry Muhomor 03883eb2ce mte: rename arm_mte_store_tags_and_clear() to arm_mte_tag_and_clear_mem() 2023-10-30 14:20:53 -04:00
Dmitry Muhomor 7a6dbd8152 mte: add comment about the reserved slab canary value 2023-10-30 14:20:53 -04:00
Dmitry Muhomor f16ef601d4 memtag_test: improve capturing of test results
Using debuggerd + logcat parsing is unreliable and slow, print SEGV signal code to stderr instead.
2023-10-30 14:20:53 -04:00
Dmitry Muhomor 155800526a memtag_test: improve tag_distinctness test
- check that tag distinctess checks are actually reached (it was previously verified manually by
looking at the now-removed printf output)
- check that only non-reserved tags are used
- check that all of non-reserved tags are used
- print tag usage statistics at the end of run
2023-10-30 14:20:53 -04:00
Dmitry Muhomor 28d5d394cf memtag_test: remove usages of rand()
It didn't work correctly due to not being seeded and its usage wasn't necessary.
2023-10-30 14:20:53 -04:00
Dmitry Muhomor 577d9583eb mte: add licensing info for code that was copied from scudo 2023-10-30 14:20:53 -04:00
Dmitry Muhomor 93aa9eefe4 mte: make h_malloc_disable_memory_tagging() thread-safe 2023-10-30 14:20:53 -04:00
Dmitry Muhomor 01a199e19e mte: move is_memtag_enabled to read-only allocator data 2023-10-30 14:20:53 -04:00
Dmitry Muhomor 576328b1b4 android: add MTE tests
To run them, connect an MTE-enabled device via adb and execute `atest HMallocTest:MemtagTest`.

Since these tests are not deterministic (and neither is hardened_malloc itself), it's better to run
them multiple times, e.g. `atest --iterations 30 HMallocTest:MemtagTest`.

There are also CTS tests that are useful for checking correctness of the Android integration:
`atest CtsTaggingHostTestCases`
2023-10-30 14:20:53 -04:00
Dmitry Muhomor 5137d2da4d android: enable MTE on devices that declare having it 2023-10-30 14:20:53 -04:00
Dmitry Muhomor f042a6b9b0 android: add function for disabling MTE at runtime
On Android, MTE is always enabled in Zygote, and is disabled after fork for apps that didn't opt-in
to MTE.

Depends on the slab canary adjustments in the previous commit.
2023-10-30 14:20:53 -04:00
Dmitry Muhomor 001fc86585 mte: disable slab canaries when MTE is on
Canary with the "0" value is now reserved to support re-enabling slab canaries if MTE is turned off
at runtime.
2023-10-30 14:20:53 -04:00
Dmitry Muhomor 70c91f4c3e mte: disable write-after-free check for slab allocations when MTE is on
Freed slab memory is tagged with a reserved tag value that is never used for live allocations.
2023-10-30 14:20:53 -04:00
Dmitry Muhomor e3686ae457 add support for Arm MTE memory tagging
- tag slab allocations with [1..14] tags
- tag freed slab allocations with the "15" tag value to detect accesses to freed slab memory
- when generating tag value for a slab slot, always exclude most recent tag value for that slot
(to make use-after-free detection more reliable) and most recent tag values of its immediate
neighbors (to detect linear overflows and underflows)
2023-10-30 14:20:53 -04:00
Dmitry Muhomor 19a46e0f96 add helper functions for using u8 array as u4 array 2023-10-30 14:20:53 -04:00
Dmitry Muhomor 8d5c631224 android: implement fatal_error() via async_safe_fatal()
async_safe_fatal() performs the following steps:
- logs the error message to stderr and logcat
- passes error message to debuggerd via android_set_abort_message(). debuggerd then saves the error
message in the crash report file ("tombstone")
- calls abort()
2023-09-28 13:47:11 -04:00