diff options
Diffstat (limited to 'executor/executor_linux.cc')
| -rw-r--r-- | executor/executor_linux.cc | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/executor/executor_linux.cc b/executor/executor_linux.cc index 4b88946dd..2df74250c 100644 --- a/executor/executor_linux.cc +++ b/executor/executor_linux.cc @@ -144,11 +144,13 @@ void cover_open() if (ioctl(th->cover_fd, kcov_init_trace, kCoverSize)) fail("cover init trace write failed"); size_t mmap_alloc_size = kCoverSize * (is_kernel_64_bit ? 8 : 4); - th->cover_data = (char*)mmap(NULL, mmap_alloc_size, - PROT_READ | PROT_WRITE, MAP_SHARED, th->cover_fd, 0); + th->cover_data = (char*)mmap(NULL, mmap_alloc_size, PROT_READ, MAP_SHARED, th->cover_fd, 0); th->cover_end = th->cover_data + mmap_alloc_size; if (th->cover_data == MAP_FAILED) fail("cover mmap failed"); + // We only write to the first page, so protect the rest from fuzzer. + if (mprotect(th->cover_data, SYZ_PAGE_SIZE, PROT_READ | PROT_WRITE)) + fail("cover mprotect failed"); } } |