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=poHUam60Bko5BpiJ9jn0fAupFUYexvdU... 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;