From 169b38373fd4a7d47cac0e5fdeeae90b8c076f32 Mon Sep 17 00:00:00 2001 From: Shanker Donthineni Date: Wed, 6 Apr 2016 12:49:24 -0500 Subject: [PATCH] mailbox: pcc: Don't access an unmapped memory address space The acpi_pcc_probe() may end up accessing memory outside of the PCCT table space causing the kernel panic(). Increment the pcct_entry pointer after parsing 'HW-reduced Communications Subspace' to fix the problem. This change also enables the parsing of subtable at index 0. Signed-off-by: Shanker Donthineni Acked-by: Ashwin Chaugule Signed-off-by: Rafael J. Wysocki --- drivers/mailbox/pcc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c index ac11a9b395d3..9d3955e6ab44 100644 --- a/drivers/mailbox/pcc.c +++ b/drivers/mailbox/pcc.c @@ -367,8 +367,6 @@ static int __init acpi_pcc_probe(void) struct acpi_generic_address *db_reg; struct acpi_pcct_hw_reduced *pcct_ss; pcc_mbox_channels[i].con_priv = pcct_entry; - pcct_entry = (struct acpi_subtable_header *) - ((unsigned long) pcct_entry + pcct_entry->length); /* If doorbell is in system memory cache the virt address */ pcct_ss = (struct acpi_pcct_hw_reduced *)pcct_entry; @@ -376,6 +374,8 @@ static int __init acpi_pcc_probe(void) if (db_reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) pcc_doorbell_vaddr[i] = acpi_os_ioremap(db_reg->address, db_reg->bit_width/8); + pcct_entry = (struct acpi_subtable_header *) + ((unsigned long) pcct_entry + pcct_entry->length); } pcc_mbox_ctrl.num_chans = count; -- 2.30.2