drm/nouveau/pmu: do not assume a PMU is present (Closes: #809481)

debian/changelog

@@ -13,6 +13,7 @@ linux (4.3.3-3) UNRELEASED; urgency=medium
   * KEYS: Fix race between read and revoke (CVE-2015-7550)
   * [armhf] udeb: Add modular clock, GPIO, PHY and regulator drivers to
     core-modules (Closes: #809521)
+  * drm/nouveau/pmu: do not assume a PMU is present (Closes: #809481)
 
   [ Salvatore Bonaccorso ]
   * ovl: fix permission checking for setattr (CVE-2015-8660)

debian/patches/bugfix/all/drm-nouveau-pmu-do-not-assume-a-pmu-is-present.patch

@@ -0,0 +1,29 @@
+From: Alexandre Courbot <acourbot@nvidia.com>
+Date: Thu, 3 Sep 2015 17:39:52 +0900
+Subject: drm/nouveau/pmu: do not assume a PMU is present
+Origin: https://git.kernel.org/linus/579b7c58215329803ce184704463de09f0f310ac
+Bug-Debian: https://bugs.debian.org/809481
+
+Some devices may not have a PMU. Avoid a NULL pointer dereference in
+such cases by checking whether the pointer given to nvkm_pmu_pgob() is
+valid.
+
+Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
+Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
+---
+ drivers/gpu/drm/nouveau/nvkm/subdev/pmu/base.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/pmu/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/pmu/base.c
+index 27a79c0..d95eb86 100644
+--- a/drivers/gpu/drm/nouveau/nvkm/subdev/pmu/base.c
++++ b/drivers/gpu/drm/nouveau/nvkm/subdev/pmu/base.c
+@@ -28,7 +28,7 @@
+ void
+ nvkm_pmu_pgob(struct nvkm_pmu *pmu, bool enable)
+ {
+-	if (pmu->func->pgob)
++	if (pmu && pmu->func->pgob)
+ 		pmu->func->pgob(pmu, enable);
+ }
+ 

debian/patches/series

@@ -128,3 +128,4 @@ bugfix/all/xen-pciback-don-t-allow-msi-x-ops-if-pci_command_mem.patch
 bugfix/all/ptrace-being-capable-wrt-a-process-requires-mapped-uids-gids.patch
 bugfix/all/keys-fix-race-between-read-and-revoke.patch
 bugfix/x86/KVM-x86-Reload-pit-counters-for-all-channels-when-re.patch
+bugfix/all/drm-nouveau-pmu-do-not-assume-a-pmu-is-present.patch