Setting variables in a Linux kernel instance does not work with `pwndbg`

Description

Setting variables on a running Linux kernel (6.5.7) that is being debugged with kgdb, pwndbg and QEMU doesn't work, even if it does on common gdb.

Steps to reproduce

• Download the source to the Linux kernel: https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-6.5.7.tar.xz
  • Note: I used the virtual machine image provided here as part of a university course: https://teaching.os.rwth-aachen.de/LKP/data/lkp-arch.img
  • Download the config provided here: https://teaching.os.rwth-aachen.de/LKP/data/config-lkp, enable all relevant debugging-related options
• Compile the kernel and boot it using QEMU with the kernel options rw console=ttyS0 kgdboc=ttyS1 kgdbwait nokaslr (and the QEMU option -serial mon:stdio -serial tcp::1234,server,nowait)
• On the root folder of the kernel sources, run gdb ./vmlinux
• On Linux (running on QEMU), run continue, let the machine boot, then run echo g > /proc/sysrq-trigger to invoke the debugger again
• Try running set variable nit_uts_ns.name.sysname = "Test"

pwndbg> set variable init_uts_ns.name.release = "dskasd"
Cannot access memory at address 0xffffffff82c66b42

• This should not happen, as it works on GDB.

My setup

pwndbg> version
Gdb:      15.0.50.20240403-git
Python:   3.12.3 (main, Sep 11 2024, 14:17:37) [GCC 13.2.0]
Pwndbg:   2024.08.29 build: 88c363a6
Capstone: 5.0.1280