[04/28] accel/tcg: Replace g_memdup() by g_memdup2_qemu()

Commit Message

Philippe Mathieu-Daudé Sept. 3, 2021, 11:06 a.m. UTC

Per https://discourse.gnome.org/t/port-your-module-from-g-memdup-to-g-memdup2-now/5538

  The old API took the size of the memory to duplicate as a guint,
  whereas most memory functions take memory sizes as a gsize. This
  made it easy to accidentally pass a gsize to g_memdup(). For large
  values, that would lead to a silent truncation of the size from 64
  to 32 bits, and result in a heap area being returned which is
  significantly smaller than what the caller expects. This can likely
  be exploited in various modules to cause a heap buffer overflow.

Replace g_memdup() by the safer g_memdup2_qemu() wrapper.

Signed-off-by: Philippe Mathieu-Daudé <[e-mail]>
---
 accel/tcg/cputlb.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Patch

diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
index b1e5471f949..1d5069a30d1 100644
--- a/accel/tcg/cputlb.c
+++ b/accel/tcg/cputlb.c
@@ -826,7 +826,7 @@  void tlb_flush_range_by_mmuidx(CPUState *cpu, target_ulong addr,
         tlb_flush_range_by_mmuidx_async_0(cpu, d);
     } else {
         /* Otherwise allocate a structure, freed by the worker.  */
-        TLBFlushRangeData *p = g_memdup(&d, sizeof(d));
+        TLBFlushRangeData *p = g_memdup2_qemu(&d, sizeof(d));
         async_run_on_cpu(cpu, tlb_flush_range_by_mmuidx_async_1,
                          RUN_ON_CPU_HOST_PTR(p));
     }
@@ -868,7 +868,7 @@  void tlb_flush_range_by_mmuidx_all_cpus(CPUState *src_cpu,
     /* Allocate a separate data block for each destination cpu.  */
     CPU_FOREACH(dst_cpu) {
         if (dst_cpu != src_cpu) {
-            TLBFlushRangeData *p = g_memdup(&d, sizeof(d));
+            TLBFlushRangeData *p = g_memdup2_qemu(&d, sizeof(d));
             async_run_on_cpu(dst_cpu,
                              tlb_flush_range_by_mmuidx_async_1,
                              RUN_ON_CPU_HOST_PTR(p));
@@ -918,13 +918,13 @@  void tlb_flush_range_by_mmuidx_all_cpus_synced(CPUState *src_cpu,
     /* Allocate a separate data block for each destination cpu.  */
     CPU_FOREACH(dst_cpu) {
         if (dst_cpu != src_cpu) {
-            p = g_memdup(&d, sizeof(d));
+            p = g_memdup2_qemu(&d, sizeof(d));
             async_run_on_cpu(dst_cpu, tlb_flush_range_by_mmuidx_async_1,
                              RUN_ON_CPU_HOST_PTR(p));
         }
     }
 
-    p = g_memdup(&d, sizeof(d));
+    p = g_memdup2_qemu(&d, sizeof(d));
     async_safe_run_on_cpu(src_cpu, tlb_flush_range_by_mmuidx_async_1,
                           RUN_ON_CPU_HOST_PTR(p));
 }