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 4.4-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-4.4 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: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
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
@@ -305,9 +305,10 @@ 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-4.4/drivers-hv-balloon-keep-track-of-where-ha_region-starts.patch
queue-4.4/drivers-hv-get-rid-of-timeout-in-vmbus_open.patch
queue-4.4/hv-don-t-reset-hv_context.tsc_page-on-crash.patch
queue-4.4/drivers-hv-don-t-leak-memory-in-vmbus_establish_gpadl.patch
queue-4.4/tools-hv-kvp-ensure-kvp-device-fd-is-closed-on-exec.patch
queue-4.4/drivers-hv-balloon-account-for-gaps-in-hot-add-regions.patch