Since commit 7fef431be9c9 ("mm/page_alloc: place pages to tail
in __free_pages_core()") the following use after free occurs
intermittently when acpi tables are accessed.BUG: KASAN: use-after-free in ibft_init+0x134/0xc49 Read of size 4 at addr ffff8880be453004 by task swapper/0/1 CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc1-7a7fd0d #1 Call Trace: dump_stack+0xf6/0x158 print_address_description.constprop.9+0x41/0x60 kasan_report.cold.14+0x7b/0xd4 __asan_report_load_n_noabort+0xf/0x20 ibft_init+0x134/0xc49 do_one_initcall+0xc4/0x3e0 kernel_init_freeable+0x5af/0x66b kernel_init+0x16/0x1d0 ret_from_fork+0x22/0x30 ACPI tables mapped via kmap() do not have their mapped pages reserved and the pages can be "stolen" by the buddy allocator. Use memblock_reserve() to reserve all the ACPI table pages. Signed-off-by: George Kennedy <[email protected]> --- arch/x86/kernel/setup.c | 3 +-- drivers/acpi/acpica/tbinstal.c | 4 ++++ 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index d883176..97deea3 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1046,6 +1046,7 @@ void __init setup_arch(char **cmdline_p) cleanup_highmap(); memblock_set_current_limit(ISA_END_ADDRESS); + acpi_boot_table_init(); e820__memblock_setup(); /* @@ -1139,8 +1140,6 @@ void __init setup_arch(char **cmdline_p) /* * Parse the ACPI tables for possible boot-time SMP configuration. */ - acpi_boot_table_init(); - early_acpi_boot_init(); initmem_init(); diff --git a/drivers/acpi/acpica/tbinstal.c b/drivers/acpi/acpica/tbinstal.c index 8d1e5b5..4e32b22 100644 --- a/drivers/acpi/acpica/tbinstal.c +++ b/drivers/acpi/acpica/tbinstal.c @@ -8,6 +8,7 @@ *****************************************************************************/ #include <acpi/acpi.h> +#include <linux/memblock.h> #include "accommon.h" #include "actables.h" @@ -58,6 +59,9 @@ new_table_desc->flags, new_table_desc->pointer); + memblock_reserve(new_table_desc->address, + PAGE_ALIGN(new_table_desc->pointer->length)); + acpi_tb_print_table_header(new_table_desc->address, new_table_desc->pointer); -- 1.8.3.1
