4.9-stable review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter dan.carpenter@oracle.com
[ Upstream commit c37a3c94775855567b90f91775b9691e10bd2806 ]
If acpi_id is == nr_acpi_bits, then we access one element beyond the end of the acpi_psd[] array or we set one bit beyond the end of the bit map when we do __set_bit(acpi_id, acpi_id_present);
Fixes: 59a568029181 ("xen/acpi-processor: C and P-state driver that uploads said data to hypervisor.") Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Reviewed-by: Joao Martins joao.m.martins@oracle.com Reviewed-by: Juergen Gross jgross@suse.com Signed-off-by: Boris Ostrovsky boris.ostrovsky@oracle.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/xen/xen-acpi-processor.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/xen/xen-acpi-processor.c +++ b/drivers/xen/xen-acpi-processor.c @@ -362,9 +362,9 @@ read_acpi_id(acpi_handle handle, u32 lvl } /* There are more ACPI Processor objects than in x2APIC or MADT. * This can happen with incorrect ACPI SSDT declerations. */ - if (acpi_id > nr_acpi_bits) { - pr_debug("We only have %u, trying to set %u\n", - nr_acpi_bits, acpi_id); + if (acpi_id >= nr_acpi_bits) { + pr_debug("max acpi id %u, trying to set %u\n", + nr_acpi_bits - 1, acpi_id); return AE_OK; } /* OK, There is a ACPI Processor object */