On Thu, Jun 06, 2024 at 03:31:49PM +0200, Daniel v. Kirschten wrote: > If a module is being loaded, and the .gnu.linkonce.this_module section > in the module's ELF file does not have the WRITE flag, the kernel will > map the finished module struct of that module as read-only. > This causes a kernel panic when the struct is written to the first time > after it has been marked read-only. Currently this happens in > complete_formation in kernel/module/main.c:2765 when the module's state is > set to MODULE_STATE_COMING, just after setting up the memory protections. How did you find this issue? > Down the line, this seems to lead to unpredictable freezes when trying to > load other modules - I guess this is due to some structures not being > cleaned up properly, but I didn't investigate this further. > > A check already exists which verifies that .gnu.linkonce.this_module > is ALLOC. This patch simply adds an analogous check for WRITE. Can you check to ensure our modules generated have a respective check to ensure this check exists at build time? That would proactively inform userspace when a built module is not built correctly, and the tool responsible can be identified. Luis
