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| author | Dmitry Vyukov <dvyukov@google.com> | 2017-01-25 11:01:30 +0100 |
|---|---|---|
| committer | Dmitry Vyukov <dvyukov@google.com> | 2017-01-25 11:01:30 +0100 |
| commit | f810d0844478c385985e2d0fe0a6a603a7b1c8bd (patch) | |
| tree | 6f1c5ff716e3e22d1f3cda7d681d349fd7f659fb /executor/executor.cc | |
| parent | 40723a067e2216f643485b732f90202b38b59e4b (diff) | |
executor: protect against memory corruptions better
Fuzzer has figured out how to corrupt input/output shmem regions
abusing the text memcpy in syz_kvm_setup_cpu. It guessed a negative
text_size value that causes the memcpy to overwrite shmem regions.
Protect better against such cases:
1. Make text_size unsigned (there is already a check that it is less than 1000).
2. Map input region as readable only, we don't write to it.
3. Add address sanity check to segv_handler, if we see that we are writing
into executable data, it's better to crash instantly.
Diffstat (limited to 'executor/executor.cc')
| -rw-r--r-- | executor/executor.cc | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/executor/executor.cc b/executor/executor.cc index 9ef2248be..03999559a 100644 --- a/executor/executor.cc +++ b/executor/executor.cc @@ -139,7 +139,7 @@ int main(int argc, char** argv) } prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); - if (mmap(&input_data[0], kMaxInput, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_FIXED, kInFd, 0) != &input_data[0]) + if (mmap(&input_data[0], kMaxInput, PROT_READ, MAP_PRIVATE | MAP_FIXED, kInFd, 0) != &input_data[0]) fail("mmap of input file failed"); if (mmap(&output_data[0], kMaxOutput, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, kOutFd, 0) != &output_data[0]) fail("mmap of output file failed"); |