On 10/01/2025 02:50, Dave Young wrote: > Hi Usama, > > On Thu, 9 Jan 2025 at 06:00, Usama Arif <usamaarif642@xxxxxxxxx> wrote: >> >> When this area is not reserved, it comes up as usable in >> /sys/firmware/memmap. This means that kexec, which uses that memmap >> to find usable memory regions, can select the region where >> efi_mem_attr_table is and overwrite it and relocate_kernel. > > Is the attr table BOOT SERVICE DATA? If so, does efi_mem_reserve() > work for you? > Just refer to esrt.c. > Hi Dave, Its a bit difficult to reproduce the problem and therefore test the fix, but we are seeing it a lot in production. Ard proposed the same thing in https://lore.kernel.org/all/6b4780a5-ada0-405e-9f0a-4d2186177f29@xxxxxxxxx/ but as I mentioned there, I dont think that efi_mem_reserve would help, as efi_mem_reserve changes e820_table, while kexec looks at /sys/firmware/memmap which uses e820_table_firmware. Thanks, Usama > Thanks > Dave >
