diff options
| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-03-23 20:26:52 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-03-29 19:26:04 +0200 |
| commit | 1a1c130ab7575498eed5bcf7220037ae09cd1f8a (patch) | |
| tree | fe570b16cd0597b532b12981ec4965258e667298 /drivers | |
| parent | a5e13c6df0e41702d2b2c77c8ad41677ebb065b3 (diff) | |
ACPI: tables: x86: Reserve memory occupied by ACPI tables
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>
Tested-by: George Kennedy <george.kennedy@oracle.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: 5.10+ <stable@vger.kernel.org> # 5.10+
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/acpi/tables.c | 42 |
1 files changed, 39 insertions, 3 deletions
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c index e48690a006a4..9d581045acff 100644 --- a/drivers/acpi/tables.c +++ b/drivers/acpi/tables.c @@ -780,7 +780,7 @@ acpi_status acpi_os_table_override(struct acpi_table_header *existing_table, } /* - * 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(struct acpi_table_header *existing_table, * 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; } |