| From df9e4f8ea1b0f3dd1a8bb89cf48d5a4cccffa69e Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Thu, 30 Jan 2020 16:48:16 -0800 |
| Subject: x86/boot: Handle malformed SRAT tables during early ACPI parsing |
| |
| From: Steven Clarkson <sc@lambdal.com> |
| |
| [ Upstream commit 2b73ea3796242608b4ccf019ff217156c92e92fe ] |
| |
| Break an infinite loop when early parsing of the SRAT table is caused |
| by a subtable with zero length. Known to affect the ASUS WS X299 SAGE |
| motherboard with firmware version 1201 which has a large block of |
| zeros in its SRAT table. The kernel could boot successfully on this |
| board/firmware prior to the introduction of early parsing this table or |
| after a BIOS update. |
| |
| [ bp: Fixup whitespace damage and commit message. Make it return 0 to |
| denote that there are no immovable regions because who knows what |
| else is broken in this BIOS. ] |
| |
| Fixes: 02a3e3cdb7f1 ("x86/boot: Parse SRAT table and count immovable memory regions") |
| Signed-off-by: Steven Clarkson <sc@lambdal.com> |
| Signed-off-by: Borislav Petkov <bp@suse.de> |
| Cc: linux-acpi@vger.kernel.org |
| Link: https://bugzilla.kernel.org/show_bug.cgi?id=206343 |
| Link: https://lkml.kernel.org/r/CAHKq8taGzj0u1E_i=poHUam60Bko5BpiJ9jn0fAupFUYexvdUQ@mail.gmail.com |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| arch/x86/boot/compressed/acpi.c | 6 ++++++ |
| 1 file changed, 6 insertions(+) |
| |
| diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c |
| index 25019d42ae937..ef2ad7253cd5e 100644 |
| --- a/arch/x86/boot/compressed/acpi.c |
| +++ b/arch/x86/boot/compressed/acpi.c |
| @@ -393,7 +393,13 @@ int count_immovable_mem_regions(void) |
| table = table_addr + sizeof(struct acpi_table_srat); |
| |
| while (table + sizeof(struct acpi_subtable_header) < table_end) { |
| + |
| sub_table = (struct acpi_subtable_header *)table; |
| + if (!sub_table->length) { |
| + debug_putstr("Invalid zero length SRAT subtable.\n"); |
| + return 0; |
| + } |
| + |
| if (sub_table->type == ACPI_SRAT_TYPE_MEMORY_AFFINITY) { |
| struct acpi_srat_mem_affinity *ma; |
| |
| -- |
| 2.20.1 |
| |