From 1a1c130ab7575498eed5bcf7220037ae09cd1f8a Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 23 Mar 2021 20:26:52 +0100 Subject: 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 Tested-by: George Kennedy Signed-off-by: Rafael J. Wysocki Reviewed-by: Mike Rapoport Cc: 5.10+ # 5.10+ --- 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(-) diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 7bdc0239a943..14cd3186dc77 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/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 diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index d883176ef2ce..5ecd69a48393 100644 --- a/arch/x86/kernel/setup.c +++ b/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(); 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; } diff --git a/include/linux/acpi.h b/include/linux/acpi.h index fcdaab723916..3bdcfc4401b7 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -222,10 +222,14 @@ void __iomem *__acpi_map_table(unsigned long phys, unsigned long size); 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) -- cgit v1.2.3 From 3e759425cc3cf9a43392309819d34c65a3644c59 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Tue, 30 Mar 2021 20:49:32 +0200 Subject: ACPI: scan: Fix _STA getting called on devices with unmet dependencies Commit 71da201f38df ("ACPI: scan: Defer enumeration of devices with _DEP lists") dropped the following 2 lines from acpi_init_device_object(): /* Assume there are unmet deps until acpi_device_dep_initialize() runs */ device->dep_unmet = 1; Leaving the initial value of dep_unmet at the 0 from the kzalloc(). This causes the acpi_bus_get_status() call in acpi_add_single_object() to actually call _STA, even though there maybe unmet deps, leading to errors like these: [ 0.123579] ACPI Error: No handler for Region [ECRM] (00000000ba9edc4c) [GenericSerialBus] (20170831/evregion-166) [ 0.123601] ACPI Error: Region GenericSerialBus (ID=9) has no handler (20170831/exfldio-299) [ 0.123618] ACPI Error: Method parse/execution failed \_SB.I2C1.BAT1._STA, AE_NOT_EXIST (20170831/psparse-550) Fix this by re-adding the dep_unmet = 1 initialization to acpi_init_device_object() and modifying acpi_bus_check_add() to make sure that dep_unmet always gets setup there, overriding the initial 1 value. This re-fixes the issue initially fixed by commit 63347db0affa ("ACPI / scan: Use acpi_bus_get_status() to initialize ACPI_TYPE_DEVICE devs"), which introduced the removed "device->dep_unmet = 1;" statement. This issue was noticed; and the fix tested on a Dell Venue 10 Pro 5055. Fixes: 71da201f38df ("ACPI: scan: Defer enumeration of devices with _DEP lists") Suggested-by: Rafael J. Wysocki Signed-off-by: Hans de Goede Cc: 5.11+ # 5.11+ Signed-off-by: Rafael J. Wysocki --- drivers/acpi/scan.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 84bb7c1929f1..6efe7edd7b1e 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1670,6 +1670,8 @@ void acpi_init_device_object(struct acpi_device *device, acpi_handle handle, device_initialize(&device->dev); dev_set_uevent_suppress(&device->dev, true); acpi_init_coherency(device); + /* Assume there are unmet deps to start with. */ + device->dep_unmet = 1; } void acpi_device_add_finalize(struct acpi_device *device) @@ -1933,6 +1935,8 @@ static void acpi_scan_dep_init(struct acpi_device *adev) { struct acpi_dep_data *dep; + adev->dep_unmet = 0; + mutex_lock(&acpi_dep_list_lock); list_for_each_entry(dep, &acpi_dep_list, node) { @@ -1980,7 +1984,13 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep, return AE_CTRL_DEPTH; acpi_scan_init_hotplug(device); - if (!check_dep) + /* + * If check_dep is true at this point, the device has no dependencies, + * or the creation of the device object would have been postponed above. + */ + if (check_dep) + device->dep_unmet = 0; + else acpi_scan_dep_init(device); out: -- cgit v1.2.3