From 84b9dd08af3cabe2c588ea9775c42575da45fd40 Mon Sep 17 00:00:00 2001 From: Kostya Kortchinsky Date: Mon, 31 Jul 2017 18:45:17 +0000 Subject: [msan] Check for pvalloc overflow Summary: `CheckForPvallocOverflow` was introduced with D35818 to detect when pvalloc would wrap when rounding up to the next multiple of the page size. Add this check to MSan's pvalloc implementation. Reviewers: alekseyshl Reviewed By: alekseyshl Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D36093 git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@309601 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/msan/msan_allocator.cc | 6 +++++- lib/msan/tests/msan_test.cc | 11 +++++++++++ 2 files changed, 16 insertions(+), 1 deletion(-) (limited to 'lib/msan') diff --git a/lib/msan/msan_allocator.cc b/lib/msan/msan_allocator.cc index 1034dbdf9..1b134e15a 100644 --- a/lib/msan/msan_allocator.cc +++ b/lib/msan/msan_allocator.cc @@ -255,8 +255,12 @@ void *msan_valloc(uptr size, StackTrace *stack) { void *msan_pvalloc(uptr size, StackTrace *stack) { uptr PageSize = GetPageSizeCached(); + if (UNLIKELY(CheckForPvallocOverflow(size, PageSize))) { + errno = errno_ENOMEM; + return Allocator::FailureHandler::OnBadRequest(); + } // pvalloc(0) should allocate one page. - size = size == 0 ? PageSize : RoundUpTo(size, PageSize); + size = size ? RoundUpTo(size, PageSize) : PageSize; return SetErrnoOnNull(MsanAllocate(stack, size, PageSize, false)); } diff --git a/lib/msan/tests/msan_test.cc b/lib/msan/tests/msan_test.cc index b2d5f7c60..b4cc8493a 100644 --- a/lib/msan/tests/msan_test.cc +++ b/lib/msan/tests/msan_test.cc @@ -3449,6 +3449,17 @@ TEST(MemorySanitizer, pvalloc) { EXPECT_EQ(0U, (uintptr_t)p % PageSize); EXPECT_EQ(PageSize, __sanitizer_get_allocated_size(p)); free(p); + + // Overflows in pvalloc should be caught. + errno = 0; + p = pvalloc((uintptr_t)-PageSize); + EXPECT_EQ(p, nullptr); + EXPECT_EQ(errno, ENOMEM); + + errno = 0; + p = pvalloc((uintptr_t)-1); + EXPECT_EQ(p, nullptr); + EXPECT_EQ(errno, ENOMEM); } #endif -- cgit v1.2.3