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

[George Kennedy <george.kennedy@oracle.com>]

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.