ACPI: APEI: Fix possible out-of-bounds access to BERT region (1c0d9b1c) · Commits · 戴 / test

Check that the length recorded in the generic error status block is within the region before checking the contents of the region itself. Otherwise it may result in an out-of-bounds access if the system firmware has generated a status block with an invalid length (larger than the mapped region). Also move the block_status check so that it only happens after the block has been verified to be within the mapped region. Signed-off-by:

Ross Lagerwall <ross.lagerwall@citrix.com> Acked-by:

Borislav Petkov <bp@suse.de> Tested-by:

Tyler Baicar <baicar.tyler@gmail.com> Signed-off-by:

Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/apei/bert.c

+10 −13

Original line number	Diff line number	Diff line
		@@ -42,22 +42,23 @@ static void __init bert_print_all(struct acpi_bert_region *region,
		int remain = region_len;
		u32 estatus_len;

		while (remain >= sizeof(struct acpi_bert_region)) {
		estatus_len = cper_estatus_len(estatus);
		if (remain < estatus_len) {
		pr_err(FW_BUG "Truncated status block (length: %u).\n",
		estatus_len);
		return;
		}

		/* No more error records. */
		if (!estatus->block_status)
		return;

		while (remain > sizeof(struct acpi_bert_region)) {
		if (cper_estatus_check(estatus)) {
		pr_err(FW_BUG "Invalid error record.\n");
		return;
		}

		estatus_len = cper_estatus_len(estatus);
		if (remain < estatus_len) {
		pr_err(FW_BUG "Truncated status block (length: %u).\n",
		estatus_len);
		return;
		}

		pr_info_once("Error records from previous boot:\n");

		cper_estatus_print(KERN_INFO HW_ERR, estatus);
		@@ -70,10 +71,6 @@ static void __init bert_print_all(struct acpi_bert_region *region,
		estatus->block_status = 0;

		estatus = (void *)estatus + estatus_len;
		/* No more error records. */
		if (!estatus->block_status)
		return;

		remain -= estatus_len;
		}
		}

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