linux/drivers/xen
Stefano Stabellini 4f1adc3f57 xen: detect uninitialized xenbus in xenbus_init
commit 36e8f60f0867d3b70d398d653c17108459a04efe upstream.

If the xenstore page hasn't been allocated properly, reading the value
of the related hvm_param (HVM_PARAM_STORE_PFN) won't actually return
error. Instead, it will succeed and return zero. Instead of attempting
to xen_remap a bad guest physical address, detect this condition and
return early.

Note that although a guest physical address of zero for
HVM_PARAM_STORE_PFN is theoretically possible, it is not a good choice
and zero has never been validly used in that capacity.

Also recognize all bits set as an invalid value.

For 32-bit Linux, any pfn above ULONG_MAX would get truncated. Pfns
above ULONG_MAX should never be passed by the Xen tools to HVM guests
anyway, so check for this condition and return early.

Cc: stable@vger.kernel.org
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Link: https://lore.kernel.org/r/20211123210748.1910236-1-sstabellini@kernel.org
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-01 09:23:28 +01:00
..
events
xen-pciback xen-pciback: Fix return in pm_ctrl_init() 2021-11-17 09:48:46 +01:00
xenbus xen: detect uninitialized xenbus in xenbus_init 2021-12-01 09:23:28 +01:00
xenfs
acpi.c
arm-device.c
balloon.c xen/balloon: add late_initcall_sync() for initial ballooning done 2021-11-17 09:48:25 +01:00
biomerge.c
cpu_hotplug.c
dbgp.c
efi.c
evtchn.c
features.c
gntalloc.c
gntdev-common.h
gntdev-dmabuf.c
gntdev-dmabuf.h
gntdev.c
grant-table.c
Kconfig
Makefile
manage.c
mcelog.c
mem-reservation.c
pci.c
pcpu.c
platform-pci.c
preempt.c
privcmd-buf.c
privcmd.c
privcmd.h
pvcalls-back.c
pvcalls-front.c
pvcalls-front.h
swiotlb-xen.c
sys-hypervisor.c
time.c
xen-acpi-cpuhotplug.c
xen-acpi-memhotplug.c
xen-acpi-pad.c
xen-acpi-processor.c
xen-balloon.c
xen-front-pgdir-shbuf.c
xen-scsiback.c
xen-stub.c
xlate_mmu.c