Commit graph

11 commits

Author SHA1 Message Date
Florian Mayer
bd49c387f0 Use scudo_ring_buffer_size from process_info
This is a no-op but will be used in upcoming scudo changes that allow to
change the buffer size at process startup time, and as such we will no
longer be able to call __scudo_get_ring_buffer_size in debuggerd.

Bug: 263287052
Change-Id: I350421d1fcdf22ce3b8b73780b88c1e10fa8a074
2023-01-05 15:14:56 -08:00
Peter Collingbourne
7827991d7f Fix scudo MTE tests.
r.android.com/2108505 was intended to fix a crash in Scudo in
the case where the stack depot, region info or ring buffer were
unreadable. However, it also ended up introducing a number of bugs into
the code. It failed to call __scudo_get_error_info if the page at the
fault address was unreadable. This can happen in legitimate crash cases
if a primary allocation was close to the boundary of a mapped region,
or if the allocation was a secondary allocation with guard pages. It
also used long as the type for tags, whereas Scudo expects it to be
char. In combination this ended up causing most of the MTE tests to
fail. Therefore, mostly revert that change.

Fix the original crash by null checking the pointers returned by
AllocAndReadFully before proceeding with the rest of the function.

Bug: 233720136
Change-Id: I04d70d2abffaa35fe315d15d9224f9b412a9825d
2022-06-30 18:54:19 -07:00
liyong
381b89c8db Fix scudo fault address processing.
The code doesn't properly check if data is not read properly, so
make it fail if reads fail. Also, change the algorithm so that
first try and read the faulting page then 16 pages before and 16
pages after. Rather than trying to read every one of these pages,
stop as soon as one is unreadable. This means that the total memory
passed to the scudo error function is all valid data, rather than
potentially being some uninitialized memory.

Added new unit tests to cover scudo address processing.

Bug: 233720136

Test: All unit tests pass.
Test: atest CtsIncidentHostTestCases
Change-Id: I18a97bdee9a0c44075c1c31ccd1b546d10895be9
2022-05-26 18:50:52 -07:00
Christopher Ferris
3b7b7ba90e Use the new AndroidUnwinder object.
This simplifies most of the calls to avoid doing any Android
specific code.

Bug: 120606663

Test: All unit tests pass.
Change-Id: I511e637b9459a1f052a01e501b134e31d65b5fbe
2022-05-12 15:18:46 -07:00
Peter Collingbourne
a6fac881b2 Remove dead non-proto tombstone reporting code.
Bug: 197981919
Change-Id: I58a98070198ef0b686229bd54f87b9073df12d66
2022-03-07 17:03:18 -08:00
Christopher Ferris
22ad09b01d Update for MapInfo objects in frame data.
The frame data no longer contains map_XXX fields which represent
the map data. Now there is only a shared pointer to the MapInfo
object with which this frame is associated.

Bug: 120606663

Test: Unit tests pass.
Change-Id: I89282963f742f6fcc07e48533da4108dc16bdce9
2022-01-06 14:37:46 -08:00
Peter Collingbourne
773acaa18e Improvements to tombstone output.
- Use "likelihood" instead of "probability" since that has connotations
  of being less precise, and our probability ordering isn't very precise
  anyway.

- Hide the fault address with SEGV_MTEAERR because it is not available.

- Pad the fault address with leading zeroes to make it clearer which
  bits of the top byte (and any following bytes such as PAC signature
  bits) are set.

Bug: 206015287
Change-Id: I5e1e99b7f3e967c44781d8550bbd7158eb421b64
2021-11-11 15:05:47 -08:00
Peter Collingbourne
1a1f7d79a4 Support MTE and GWP-ASan features in proto tombstones.
Proto tombstones were missing tagged fault addresses, tagged_addr_ctrl,
tags in memory dumps and Scudo and GWP-ASan error reports. Since text
tombstones now go via protos, all of these features broke when we
switched to text tombstones generated from protos by default. Fix
the features by adding support for them to the proto format,
tombstone_proto and tombstone_proto_to_text.

Bug: 135772972
Bug: 182489365
Change-Id: I3ca854546c38755b1f6410a1f6198a44d25ed1c5
2021-03-16 10:59:39 -07:00
Peter Collingbourne
bb4b49c63c Teach debuggerd to pass the secondary ring buffer to __scudo_get_error_info().
With this change we can report memory errors involving secondary
allocations. Update the existing crasher tests to also test
UAF/overflow/underflow on allocations with sizes sufficient to trigger
the secondary allocator.

Bug: 135772972
Change-Id: Ic8925c1f18621a8f272e26d5630e5d11d6d34d38
2021-02-12 12:30:52 -08:00
Mitch Phillips
e4adff0721 [MTE] Cleanup tagged si_addr refs to fix mappings OOB bug.
Currently, all MTE failures end up displaying 'Fault address falls at
0x<addr> after any mapped regions'. Clearly when scanning, we should use
the untagged address to figure out which ranges it's in.

I've taken the liberty of removing all si_addr parsing and moving it
into the common ProcessInfo, as well as making it really explicit
whether you want the (possibly tagged) original si_addr, or whether you
want the untagged variant (for scanning /proc/maps or whatever).

This is not particularly easily testable, as ReadCrashInfo isn't easily
injectable and `dump_all_maps` should already be passed the untagged
pointer to scan for. I've tested this locally on FVP under SYNC MTE with
a simple UaF binary and noted the problem is fixed. Given that this is
making the code more clear, I'm hoping the owners see no need for a
regression test :).

Bug: 135772972
Test: On FVP, run 'adb shell MEMTAG_OPTIONS=sync sanitizer-status' and
      check that the use-after-free test ends up with the /proc/maps
      desription in the right place.
Change-Id: I220e4200c75a72474a95a67e5bbc36173a438dd2
2021-01-21 20:49:06 -08:00
Peter Collingbourne
f86225206d Add support for MTE error reports in tombstones.
Teach debuggerd to use the new scudo APIs proposed in
https://reviews.llvm.org/D77283 for extracing MTE error reports from crashed
processes, and include those reports in tombstones if possible.

Bug: 135772972
Change-Id: I082dfd0ac9d781cfed2b8c34cc73562614bb0dbb
2020-04-27 13:15:49 -07:00