Don't corrupt instruction if map offset is too large

1 files changed, 12 insertions, 0 deletions

diff --git a/frida_mode/src/instrument/instrument_arm64.c b/frida_mode/src/instrument/instrument_arm64.c
index 2256f941..a0c66697 100644
--- a/frida_mode/src/instrument/instrument_arm64.c
+++ b/frida_mode/src/instrument/instrument_arm64.c
@@ -402,6 +402,18 @@ bool instrument_write_inline(GumArm64Writer *cw, GumAddress code_addr,
 
   }
 
+  /* 
+   * The mov instruction supports up to a 16-bit offset. If our offset is out of 
+   * range, then it can end up clobbering the op-code portion of the instruction 
+   * rather than just the operands. So return false and fall back to the 
+   * alternative instrumentation.
+   */
+  if (area_offset > UINT16_MAX) {
+
+    return false;
+    
+  }
+
   code.code.mov_x0_curr_loc |= area_offset << 5;
 
   if (!instrument_patch_ardp(