Re: [PATCH] ACPI: tables: x86: Reserve memory occupied by ACPI tables

George Kennedy
2021-03-24T15:43:56Z

On 3/24/2021 9:27 AM, Rafael J. Wysocki wrote:
> On Wed, Mar 24, 2021 at 9:24 AM Mike Rapoport <rppt@linux.ibm.com> wrote:
>> On Tue, Mar 23, 2021 at 08:26:52PM +0100, Rafael J. Wysocki wrote:
>>> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>>>
>>> The following problem has been reported by George Kennedy:
>>>
>>> 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.
>>>
>>> Apparently, on the affected system, the ACPI table in question is
>>> not located in "reserved" memory, like ACPI NVS or ACPI Data, that
>>> will not be used by the buddy allocator, so the memory occupied by
>>> that table has to be explicitly reserved to prevent the buddy
>>> allocator from using it.
>>>
>>> In order to address this problem, rearrange the initialization of the
>>> ACPI tables on x86 to locate the initial tables earlier and reserve
>>> the memory occupied by them.
>>>
>>> The other architectures using ACPI should not be affected by this
>>> change.
>>>
>>> Link: https://lore.kernel.org/linux-acpi/1614802160-29362-1-git-send-email-george.kennedy@oracle.com/
>>> Reported-by: George Kennedy <george.kennedy@oracle.com>
>>> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>> FWIW:
>> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
> Thank you!
>
> George, can you please try this patch on the affected system?

Rafael,

10 for 10 successful reboots with your patch.

First, verified the failure is still there with latest 5.12.0-rc4.

George
P.S. Thanks Mike, Rafael & David

>
>>> ---
>>> arch/x86/kernel/acpi/boot.c | 25 ++++++++++++-------------
>>> arch/x86/kernel/setup.c | 8 +++-----
>>> drivers/acpi/tables.c | 42 +++++++++++++++++++++++++++++++++++++++---
>>> include/linux/acpi.h | 9 ++++++++-
>>> 4 files changed, 62 insertions(+), 22 deletions(-)
>>>
>>> Index: linux-pm/arch/x86/kernel/acpi/boot.c
>>> ===================================================================
>>> --- linux-pm.orig/arch/x86/kernel/acpi/boot.c
>>> +++ linux-pm/arch/x86/kernel/acpi/boot.c
>>> @@ -1554,10 +1554,18 @@ void __init acpi_boot_table_init(void)
>>> /*
>>> * Initialize the ACPI boot-time table parser.
>>> */
>>> - if (acpi_table_init()) {
>>> + if (acpi_locate_initial_tables())
>>> disable_acpi();
>>> - return;
>>> - }
>>> + else
>>> + acpi_reserve_initial_tables();
>>> +}
>>> +
>>> +int __init early_acpi_boot_init(void)
>>> +{
>>> + if (acpi_disabled)
>>> + return 1;
>>> +
>>> + acpi_table_init_complete();
>>>
>>> acpi_table_parse(ACPI_SIG_BOOT, acpi_parse_sbf);
>>>
>>> @@ -1570,18 +1578,9 @@ void __init acpi_boot_table_init(void)
>>> } else {
>>> printk(KERN_WARNING PREFIX "Disabling ACPI support\n");
>>> disable_acpi();
>>> - return;
>>> + return 1;
>>> }
>>> }
>>> -}
>>> -
>>> -int __init early_acpi_boot_init(void)
>>> -{
>>> - /*
>>> - * If acpi_disabled, bail out
>>> - */
>>> - if (acpi_disabled)
>>> - return 1;
>>>
>>> /*
>>> * Process the Multiple APIC Description Table (MADT), if present
>>> Index: linux-pm/arch/x86/kernel/setup.c
>>> ===================================================================
>>> --- linux-pm.orig/arch/x86/kernel/setup.c
>>> +++ linux-pm/arch/x86/kernel/setup.c
>>> @@ -1045,6 +1045,9 @@ void __init setup_arch(char **cmdline_p)
>>>
>>> cleanup_highmap();
>>>
>>> + /* Look for ACPI tables and reserve memory occupied by them. */
>>> + acpi_boot_table_init();
>>> +
>>> memblock_set_current_limit(ISA_END_ADDRESS);
>>> e820__memblock_setup();
>>>
>>> @@ -1136,11 +1139,6 @@ void __init setup_arch(char **cmdline_p)
>>>
>>> early_platform_quirks();
>>>
>>> - /*
>>> - * Parse the ACPI tables for possible boot-time SMP configuration.
>>> - */
>>> - acpi_boot_table_init();
>>> -
>>> early_acpi_boot_init();
>>>
>>> initmem_init();
>>> Index: linux-pm/include/linux/acpi.h
>>> ===================================================================
>>> --- linux-pm.orig/include/linux/acpi.h
>>> +++ linux-pm/include/linux/acpi.h
>>> @@ -222,10 +222,14 @@ void __iomem *__acpi_map_table(unsigned
>>> void __acpi_unmap_table(void __iomem *map, unsigned long size);
>>> int early_acpi_boot_init(void);
>>> int acpi_boot_init (void);
>>> +void acpi_boot_table_prepare (void);
>>> void acpi_boot_table_init (void);
>>> int acpi_mps_check (void);
>>> int acpi_numa_init (void);
>>>
>>> +int acpi_locate_initial_tables (void);
>>> +void acpi_reserve_initial_tables (void);
>>> +void acpi_table_init_complete (void);
>>> int acpi_table_init (void);
>>> int acpi_table_parse(char *id, acpi_tbl_table_handler handler);
>>> int __init acpi_table_parse_entries(char *id, unsigned long table_size,
>>> @@ -814,9 +818,12 @@ static inline int acpi_boot_init(void)
>>> return 0;
>>> }
>>>
>>> +static inline void acpi_boot_table_prepare(void)
>>> +{
>>> +}
>>> +
>>> static inline void acpi_boot_table_init(void)
>>> {
>>> - return;
>>> }
>>>
>>> static inline int acpi_mps_check(void)
>>> Index: linux-pm/drivers/acpi/tables.c
>>> ===================================================================
>>> --- linux-pm.orig/drivers/acpi/tables.c
>>> +++ linux-pm/drivers/acpi/tables.c
>>> @@ -780,7 +780,7 @@ acpi_status acpi_os_table_override(struc
>>> }
>>>
>>> /*
>>> - * acpi_table_init()
>>> + * acpi_locate_initial_tables()
>>> *
>>> * find RSDP, find and checksum SDT/XSDT.
>>> * checksum all tables, print SDT/XSDT
>>> @@ -788,7 +788,7 @@ acpi_status acpi_os_table_override(struc
>>> * result: sdt_entry[] is initialized
>>> */
>>>
>>> -int __init acpi_table_init(void)
>>> +int __init acpi_locate_initial_tables(void)
>>> {
>>> acpi_status status;
>>>
>>> @@ -803,9 +803,45 @@ int __init acpi_table_init(void)
>>> status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
>>> if (ACPI_FAILURE(status))
>>> return -EINVAL;
>>> - acpi_table_initrd_scan();
>>>
>>> + return 0;
>>> +}
>>> +
>>> +void __init acpi_reserve_initial_tables(void)
>>> +{
>>> + int i;
>>> +
>>> + for (i = 0; i < ACPI_MAX_TABLES; i++) {
>>> + struct acpi_table_desc *table_desc = &initial_tables[i];
>>> + u64 start = table_desc->address;
>>> + u64 size = table_desc->length;
>>> +
>>> + if (!start || !size)
>>> + break;
>>> +
>>> + pr_info("Reserving %4s table memory at [mem 0x%llx-0x%llx]\n",
>>> + table_desc->signature.ascii, start, start + size - 1);
>>> +
>>> + memblock_reserve(start, size);
>>> + }
>>> +}
>>> +
>>> +void __init acpi_table_init_complete(void)
>>> +{
>>> + acpi_table_initrd_scan();
>>> check_multiple_madt();
>>> +}
>>> +
>>> +int __init acpi_table_init(void)
>>> +{
>>> + int ret;
>>> +
>>> + ret = acpi_locate_initial_tables();
>>> + if (ret)
>>> + return ret;
>>> +
>>> + acpi_table_init_complete();
>>> +
>>> return 0;
>>> }
>>>
>>>
>>>
>>>
>> --
>> Sincerely yours,
>> Mike.