ACPI: Harden acpi_table_parse_entries() against BIOS bug (369d913b) · Commits · 戴 / test

Parsing acpi table entries may fall into an infinite loop on a buggy BIOS which has entry length=0 in acpi table. Instead of kernel hang with few failure clue which leads to heavy lifting debug effort, this patch hardens kernel boot by booting into non NUMA mode. The debug info left in log buffer helps people identify the issue. Signed-off-by:

Fenghua Yu <fenghua.yu@intel.com> Signed-off-by:

Len Brown <len.brown@intel.com>

drivers/acpi/tables.c

+14 −4

Original line number	Diff line number	Diff line
		@@ -240,9 +240,16 @@ acpi_table_parse_entries(char *id,
		table_end) {
		if (entry->type == entry_id
		&& (!max_entries \|\| count++ < max_entries))
		if (handler(entry, table_end)) {
		early_acpi_os_unmap_memory((char *)table_header, tbl_size);
		return -EINVAL;
		if (handler(entry, table_end))
		goto err;

		/*
		* If entry->length is 0, break from this loop to avoid
		* infinite loop.
		*/
		if (entry->length == 0) {
		pr_err(PREFIX "[%4.4s:0x%02x] Invalid zero length\n", id, entry_id);
		goto err;
		}

		entry = (struct acpi_subtable_header *)
		@@ -255,6 +262,9 @@ acpi_table_parse_entries(char *id,

		early_acpi_os_unmap_memory((char *)table_header, tbl_size);
		return count;
		err:
		early_acpi_os_unmap_memory((char *)table_header, tbl_size);
		return -EINVAL;
		}

		int __init

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