Segmenation fault while stepping on Ubuntu Linux

Author: nnelgxorzCreated Aug 28, 2026Updated Sep 9, 2026
LabelsBugDebuggerLinux

I did a little bit of snooping in gdb. Looks like a bad value comes out of a call to uwnd_step.

I'm guessing there's an unsigned arithmetic overflow somewhere in the unwinder code?

c
{ status = UWND_StepStatus_FailedMemoryRead
, missed_read_vaddr_range = {
  { min = 0
  , max = 18446744073709551608
  }
  , v = {0, 18446744073709551608}
  }
}
A fatal signal was received: Segmentation fault (11). The process is terminating.
Create a new issue with this report at https://github.com/EpicGames/raddebugger/issues.

Callstack:
1. [0x000058ea530f2e57] raddbg, lnx_signal_handler linux_base.c:1557:7
2. [0x00007e2e19442520] libc.so.6
3. [0x00007e2e195a10ca] libc.so.6,  memset-vec-unaligned-erms.S:351:0
4. [0x000058ea530f3d62] raddbg, arena_push base_arena.c:298:6
5. [0x000058ea5322de6b] raddbg, d_unwind_from_thread dbg_engine_ctrl.c:1996:15
6. [0x000058ea533080d3] raddbg, d_call_stack_artifact_create dbg_engine_ctrl.c:6491:18
7. [0x000058ea5312b6ac] raddbg, ac_async_tick artifact_cache.c:523:9
8. [0x000058ea53120504] raddbg, async_thread_entry_point base_entry_point.c:223:7
9. [0x000058ea5312a03c] raddbg, supplement_thread_base_entry_point base_entry_point.c:169:16
10. [0x000058ea53129ff9] raddbg, lnx_thread_entry_point linux_base.c:127:3
11. [0x00007e2e19494a83] libc.so.6, start_thread pthread_create.c:442:8
12. [0x00007e2e19526890] libc.so.6,  clone3.S:83:0

Version: 0.9.29 [174bdd58-dirty]

Getting to run this on Linux is so awesome. Keep up the great work!

ETA: I applied the change in #922 to be able to step at all.