Fix nullptr dereference.
If an entry is found in .eh_frame_hdr, but it's not properly in .eh_frame,
then the code would crash. The assumption that the header always points
to valid fde data is not guaranteed.
Bug: 68813077
Test: Passes new unit test that crashed before the change.
Change-Id: I914d9bda0d442cd232e2a056ae490301a8850105
diff --git a/libunwindstack/DwarfSection.cpp b/libunwindstack/DwarfSection.cpp
index 2292168..91aef80 100644
--- a/libunwindstack/DwarfSection.cpp
+++ b/libunwindstack/DwarfSection.cpp
@@ -39,6 +39,10 @@
return nullptr;
}
const DwarfFde* fde = GetFdeFromOffset(fde_offset);
+ if (fde == nullptr) {
+ return nullptr;
+ }
+
// Guaranteed pc >= pc_start, need to check pc in the fde range.
if (pc < fde->pc_end) {
return fde;
diff --git a/libunwindstack/tests/DwarfEhFrameTest.cpp b/libunwindstack/tests/DwarfEhFrameTest.cpp
index 21114da..3dbabe1 100644
--- a/libunwindstack/tests/DwarfEhFrameTest.cpp
+++ b/libunwindstack/tests/DwarfEhFrameTest.cpp
@@ -399,13 +399,25 @@
EXPECT_EQ(0x20U, fde->cie->return_address_register);
}
+TYPED_TEST_P(DwarfEhFrameTest, GetFdeFromPc_fde_not_found) {
+ this->eh_frame_->TestSetTableEntrySize(16);
+ this->eh_frame_->TestSetFdeCount(1);
+
+ typename DwarfEhFrame<TypeParam>::FdeInfo info;
+ info.pc = 0x550;
+ info.offset = 0x10500;
+ this->eh_frame_->TestSetFdeInfo(0, info);
+
+ ASSERT_EQ(nullptr, this->eh_frame_->GetFdeFromPc(0x800));
+}
+
REGISTER_TYPED_TEST_CASE_P(DwarfEhFrameTest, Init, GetFdeInfoFromIndex_expect_cache_fail,
GetFdeInfoFromIndex_read_pcrel, GetFdeInfoFromIndex_read_datarel,
GetFdeInfoFromIndex_cached, GetFdeOffsetBinary_verify,
GetFdeOffsetSequential, GetFdeOffsetSequential_last_element,
GetFdeOffsetSequential_end_check, GetFdeOffsetFromPc_fail_fde_count,
GetFdeOffsetFromPc_binary_search, GetFdeOffsetFromPc_sequential_search,
- GetCieFde32, GetCieFde64);
+ GetCieFde32, GetCieFde64, GetFdeFromPc_fde_not_found);
typedef ::testing::Types<uint32_t, uint64_t> DwarfEhFrameTestTypes;
INSTANTIATE_TYPED_TEST_CASE_P(, DwarfEhFrameTest, DwarfEhFrameTestTypes);