llvm-project/compiler-rt/test/gwp_asan/heap_buffer_overflow.cpp
Mitch Phillips dcf23e1361 [GWP-ASan] Fix up bad report for in-page underflow w/ UaF
Complex scenario, but reports when there's both a use-after-free and
buffer-underflow that is in-page (i.e. doesn't touch the guard page)
ended up generating a pretty bad report:

'Use After Free at 0x7ff392e88fef (18446744073709551615 bytes into a
1-byte allocation at 0x7ff392e88ff0) by thread 3836722 here:'

(note the 2^64-bytes-into-alloc, very cool and good!)

Fix up that case, and add a diagnostic about when you have both a
use-after-free and a buffer-overflow that it's probably a bogus report
(assuming the developer didn't *really* screw up and have a uaf+overflow
bug at the same time).

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D139885
2023-01-10 10:29:49 -08:00

18 lines
457 B
C++

// REQUIRES: gwp_asan
// RUN: %clangxx_gwp_asan %s -o %t
// RUN: %expect_crash %run %t 2>&1 | FileCheck %s
// CHECK: GWP-ASan detected a memory error
// CHECK: Buffer Overflow at 0x{{[a-f0-9]+}} ({{[1-9][0-9]*}} bytes to the right
// CHECK-SAME: of a {{[1-9][0-9]*}}-byte allocation
#include <cstdlib>
#include "page_size.h"
int main() {
char *Ptr = reinterpret_cast<char *>(malloc(pageSize()));
volatile char x = *(Ptr + pageSize());
return 0;
}