Hi, this can be triggered simply by running
# echo 0 > /sys/devices/system/cpu/cpu3/online # echo 1 > /sys/devices/system/cpu/cpu3/online [ 455.904854] ================================================================== [ 455.906108] BUG: KASAN: global-out-of-bounds in unmap_kernel_at_el0+0x70/0x1a0 [ 455.906668] Read of size 4 at addr ffff200008e3a9d8 by task swapper/3/0 [ 455.907122] [ 455.907647] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 4.17.0-rc1-00257-gbf20b92a3b12 #76 [ 455.908158] Hardware name: linux,dummy-virt (DT) [ 455.908802] Call trace: [ 455.909126] dump_backtrace+0x0/0x230 [ 455.909522] show_stack+0x14/0x20 [ 455.909848] dump_stack+0xa8/0xcc [ 455.910180] print_address_description+0x13c/0x250 [ 455.910576] kasan_report+0x254/0x328 [ 455.910985] __asan_load4+0x88/0xb0 [ 455.911326] unmap_kernel_at_el0+0x70/0x1a0 [ 455.911702] __verify_local_cpu_caps+0x78/0x178 [ 455.912098] verify_local_cpu_caps+0x4c/0x60 [ 455.912509] check_local_cpu_capabilities+0x64/0x158 [ 455.912955] secondary_start_kernel+0x178/0x260 [ 455.913366] [ 455.913586] The buggy address belongs to the variable: [ 455.914026] kpti_safe_list.26846+0x18/0x1460 [ 455.914382] [ 455.914606] Memory state around the buggy address: [ 455.915349] ffff200008e3a880: 00 00 00 01 fa fa fa fa 00 00 04 fa fa fa fa fa [ 455.915942] ffff200008e3a900: 03 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa [ 455.916483] >ffff200008e3a980: 00 00 00 06 fa fa fa fa 00 00 00 fa fa fa fa fa [ 455.917077] ^ [ 455.917539] ffff200008e3aa00: 00 00 00 00 00 00 00 05 fa fa fa fa 00 00 00 00 [ 455.918055] ffff200008e3aa80: 00 00 00 00 03 fa fa fa fa fa fa fa 00 00 00 00 [ 455.918579] ================================================================== Issue is new with 4.17-rc. Can provide .config if needed. Device was qemu-system-aarch64. Jan
signature.asc
Description: OpenPGP digital signature
