[PATCH 3.14 195/228] ACPICA: Tables: Fix invalid pointer accesses in acpi_tb_parse_root_table().

Greg Kroah-Hartman
2014-06-04T23:23:12Z

From: Lv Zheng <lv.zheng@intel.com>

commit d48dc067450d84324067f4472dc0b169e9af4454 upstream.

Linux XSDT validation mechanism backport has introduced a regreession:
Commit: 671cc68dc61f029d44b43a681356078e02d8dab8
Subject: ACPICA: Back port and refine validation of the XSDT root table.
There is a pointer still accessed after unmapping.

This patch fixes this issue. Lv Zheng.

Fixes: 671cc68dc61f (ACPICA: Back port and refine validation of the XSDT root table.)
References: https://bugzilla.kernel.org/show_bug.cgi?id=73911
References: https://bugs.archlinux.org/task/39811
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Reported-and-tested-by: Bruce Chiarelli <mano155@gmail.com>
Reported-and-tested-by: Spyros Stathopoulos <spystath@gmail.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/acpi/acpica/tbutils.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/acpi/acpica/tbutils.c
+++ b/drivers/acpi/acpica/tbutils.c
@@ -461,6 +461,7 @@ acpi_status __init acpi_tb_parse_root_ta
u32 table_count;
struct acpi_table_header *table;
acpi_physical_address address;
+ acpi_physical_address rsdt_address;
u32 length;
u8 *table_entry;
acpi_status status;
@@ -488,11 +489,14 @@ acpi_status __init acpi_tb_parse_root_ta
* as per the ACPI specification.
*/
address = (acpi_physical_address) rsdp->xsdt_physical_address;
+ rsdt_address =
+ (acpi_physical_address) rsdp->rsdt_physical_address;
table_entry_size = ACPI_XSDT_ENTRY_SIZE;
} else {
/* Root table is an RSDT (32-bit physical addresses) */

address = (acpi_physical_address) rsdp->rsdt_physical_address;
+ rsdt_address = address;
table_entry_size = ACPI_RSDT_ENTRY_SIZE;
}

@@ -515,8 +519,7 @@ acpi_status __init acpi_tb_parse_root_ta

/* Fall back to the RSDT */

- address =
- (acpi_physical_address) rsdp->rsdt_physical_address;
+ address = rsdt_address;
table_entry_size = ACPI_RSDT_ENTRY_SIZE;
}
}