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ACPICA: Tables: Do not validate signature for dynamic table load

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ACPICA commit d3c944f2cdc8c7e847b7942b1864f285189f7bce

Windows seems to allow arbitrary table signatures for Load/load_table
opcodes:
  ACPI BIOS Error (bug): Table has invalid signature [PRAD] (0x44415250)
So this patch removes dynamic load signature checks. However we need to
find a way to avoid table loading against tables like MADT. This is not
covered by this commit.

This Windows behavior has been validated on link #1. An end user bug
report can also be found on link #2.

This patch also includes simple cleanup for static load signature check
code. Reported by Ye Xiaolong, Fixed by Lv Zheng.

Link: https://github.com/acpica/acpica/commit/d3c944f2
Link: https://github.com/acpica/acpica/pull/121 [#1]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=118601 [#2]
Reported-by: Ye Xiaolong <xiaolong.ye@intel.com>
Reported-by: Olga Uhina <olga.uhina@gmail.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Lv Zheng 2017-07-10 15:23:37 +08:00 committed by Rafael J. Wysocki
parent 9b019b0f67
commit 04ba15aa55
2 changed files with 1 additions and 29 deletions
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28
drivers/acpi/acpica/tbinstal.c
View File

@ -222,34 +222,6 @@ acpi_tb_install_standard_table(acpi_physical_address address,
(void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
if (reload) {
/*
* Validate the incoming table signature.
*
* 1) Originally, we checked the table signature for "SSDT" or "PSDT".
* 2) We added support for OEMx tables, signature "OEM".
* 3) Valid tables were encountered with a null signature, so we just
* gave up on validating the signature, (05/2008).
* 4) We encountered non-AML tables such as the MADT, which caused
* interpreter errors and kernel faults. So now, we once again allow
* only "SSDT", "OEMx", and now, also a null signature. (05/2011).
*/
if ((new_table_desc.signature.ascii[0] != 0x00) &&
(!ACPI_COMPARE_NAME
(&new_table_desc.signature, ACPI_SIG_SSDT))
&& (strncmp(new_table_desc.signature.ascii, "OEM", 3))) {
ACPI_BIOS_ERROR((AE_INFO,
"Table has invalid signature [%4.4s] (0x%8.8X), "
"must be SSDT or OEMx",
acpi_ut_valid_nameseg(new_table_desc.
signature.
ascii) ?
new_table_desc.signature.
ascii : "????",
new_table_desc.signature.integer));
status = AE_BAD_SIGNATURE;
goto unlock_and_exit;
}
/* Check if table is already registered */

2
drivers/acpi/acpica/tbxfload.c
View File

@ -206,7 +206,7 @@ acpi_status acpi_tb_load_namespace(void)
for (i = 0; i < acpi_gbl_root_table_list.current_table_count; ++i) {
table = &acpi_gbl_root_table_list.tables[i];
if (!acpi_gbl_root_table_list.tables[i].address ||
if (!table->address ||
(!ACPI_COMPARE_NAME(table->signature.ascii, ACPI_SIG_SSDT)
&& !ACPI_COMPARE_NAME(table->signature.ascii,
ACPI_SIG_PSDT)