This is a note to let you know that I've just added the patch titled hv: don't reset hv_context.tsc_page on crash to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: hv-don-t-reset-hv_context.tsc_page-on-crash.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 56ef6718a1d8d77745033c5291e025ce18504159 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> Date: Wed, 7 Dec 2016 01:16:27 -0800 Subject: hv: don't reset hv_context.tsc_page on crash From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> commit 56ef6718a1d8d77745033c5291e025ce18504159 upstream. It may happen that secondary CPUs are still alive and resetting hv_context.tsc_page will cause a consequent crash in read_hv_clock_tsc() as we don't check for it being not NULL there. It is safe as we're not freeing this page anyways. Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/hv/hv.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -309,9 +309,10 @@ void hv_cleanup(bool crash) hypercall_msr.as_uint64 = 0; wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64); - if (!crash) + if (!crash) { vfree(hv_context.tsc_page); - hv_context.tsc_page = NULL; + hv_context.tsc_page = NULL; + } } #endif } Patches currently in stable-queue which might be from vkuznets@xxxxxxxxxx are queue-4.9/hv-init-percpu_list-in-hv_synic_alloc.patch queue-4.9/drivers-hv-vmbus-raise-retry-wait-limits-in-vmbus_post_msg.patch queue-4.9/hv-allocate-synic-pages-for-all-present-cpus.patch queue-4.9/hv-don-t-reset-hv_context.tsc_page-on-crash.patch