The following commit has been merged into the x86/urgent branch of tip: Commit-ID: 32ea5bc7ab8344600e87acf68cd6981c845d6edc Gitweb: https://git.kernel.org/tip/32ea5bc7ab8344600e87acf68cd6981c845d6edc Author: Steven Clarkson <sc@xxxxxxxxxxx> AuthorDate: Thu, 30 Jan 2020 16:48:16 -08:00 Committer: Borislav Petkov <bp@xxxxxxx> CommitterDate: Fri, 31 Jan 2020 19:54:35 +01:00 x86/boot: Handle malformed SRAT tables during early ACPI parsing 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. ] Fixes: 02a3e3cdb7f1 ("x86/boot: Parse SRAT table and count immovable memory regions") Signed-off-by: Steven Clarkson <sc@xxxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Cc: linux-acpi@xxxxxxxxxxxxxxx Link: https://bugzilla.kernel.org/show_bug.cgi?id=206343 Link: https://lkml.kernel.org/r/CAHKq8taGzj0u1E_i=poHUam60Bko5BpiJ9jn0fAupFUYexvdUQ@xxxxxxxxxxxxxx --- 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 25019d4..ef2ad72 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;
