This is a note to let you know that I've just added the patch titled
virtio_balloon: prevent uninitialized variable use
to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: virtio_balloon-prevent-uninitialized-variable-use.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@vger.kernel.org know about it.
From f0bb2d50dfcc519f06f901aac88502be6ff1df2c Mon Sep 17 00:00:00 2001
From: Arnd Bergmann arnd@arndb.de Date: Tue, 28 Mar 2017 18:46:59 +0200 Subject: virtio_balloon: prevent uninitialized variable use
From: Arnd Bergmann arnd@arndb.de
commit f0bb2d50dfcc519f06f901aac88502be6ff1df2c upstream.
The latest gcc-7.0.1 snapshot reports a new warning:
virtio/virtio_balloon.c: In function 'update_balloon_stats': virtio/virtio_balloon.c:258:26: error: 'events[2]' is used uninitialized in this function [-Werror=uninitialized] virtio/virtio_balloon.c:260:26: error: 'events[3]' is used uninitialized in this function [-Werror=uninitialized] virtio/virtio_balloon.c:261:56: error: 'events[18]' is used uninitialized in this function [-Werror=uninitialized] virtio/virtio_balloon.c:262:56: error: 'events[17]' is used uninitialized in this function [-Werror=uninitialized]
This seems absolutely right, so we should add an extra check to prevent copying uninitialized stack data into the statistics.
From all I can tell, this has been broken since the statistics code
was originally added in 2.6.34.
Fixes: 9564e138b1f6 ("virtio: Add memory statistics reporting to the balloon driver (V4)") Signed-off-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Ladi Prosek lprosek@redhat.com Signed-off-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/virtio/virtio_balloon.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -239,12 +239,14 @@ static void update_balloon_stats(struct all_vm_events(events); si_meminfo(&i);
+#ifdef CONFIG_VM_EVENT_COUNTERS update_stat(vb, idx++, VIRTIO_BALLOON_S_SWAP_IN, pages_to_bytes(events[PSWPIN])); update_stat(vb, idx++, VIRTIO_BALLOON_S_SWAP_OUT, pages_to_bytes(events[PSWPOUT])); update_stat(vb, idx++, VIRTIO_BALLOON_S_MAJFLT, events[PGMAJFAULT]); update_stat(vb, idx++, VIRTIO_BALLOON_S_MINFLT, events[PGFAULT]); +#endif update_stat(vb, idx++, VIRTIO_BALLOON_S_MEMFREE, pages_to_bytes(i.freeram)); update_stat(vb, idx++, VIRTIO_BALLOON_S_MEMTOT,
Patches currently in stable-queue which might be from arnd@arndb.de are
queue-4.4/kasan-rework-kconfig-settings.patch queue-4.4/hdpvr-hide-unused-variable.patch queue-4.4/mtd-ichxrom-maybe-uninitialized-with-gcc-4.9.patch queue-4.4/profile-hide-unused-functions-when-config_proc_fs.patch queue-4.4/perf-x86-shut-up-false-positive-wmaybe-uninitialized-warning.patch queue-4.4/hwrng-exynos-use-__maybe_unused-to-hide-pm-functions.patch queue-4.4/usb-cdc_subset-only-build-when-one-driver-is-enabled.patch queue-4.4/ipv4-ipconfig-avoid-unused-ic_proto_used-symbol.patch queue-4.4/revert-power-bq27xxx_battery-remove-unneeded-dependency-in-kconfig.patch queue-4.4/go7007-add-media_camera_support-dependency.patch queue-4.4/scsi-advansys-fix-build-warning-for-pci-n.patch queue-4.4/ssb-mark-ssb_bus_register-as-__maybe_unused.patch queue-4.4/tty-cyclades-cyz_interrupt-is-only-used-for-pci.patch queue-4.4/infiniband-cxgb4-use-pr-format-string-for-printing-resources.patch queue-4.4/video-fbdev-via-remove-possibly-unused-variables.patch queue-4.4/binfmt_elf-compat-avoid-unused-function-warning.patch queue-4.4/drm-gma500-remove-helper-function.patch queue-4.4/fbdev-s6e8ax0-avoid-unused-function-warnings.patch queue-4.4/netfilter-ipvs-avoid-unused-variable-warnings.patch queue-4.4/idle-i7300-add-pci-dependency.patch queue-4.4/b2c2-flexcop-avoid-unused-function-warnings.patch queue-4.4/fbdev-auo_k190x-avoid-unused-function-warnings.patch queue-4.4/cw1200-fix-bogus-maybe-uninitialized-warning.patch queue-4.4/x86-build-silence-the-build-with-make-s.patch queue-4.4/gpio-xgene-mark-pm-functions-as-__maybe_unused.patch queue-4.4/kvm-add-x86_local_apic-dependency.patch queue-4.4/arm-tegra-select-usb_ulpi-from-ehci-rather-than-platform.patch queue-4.4/asoc-mediatek-add-i2c-dependency.patch queue-4.4/reiserfs-avoid-a-wmaybe-uninitialized-warning.patch queue-4.4/scsi-advansys-fix-uninitialized-data-access.patch queue-4.4/mtd-sh_flctl-pass-fifo-as-physical-address.patch queue-4.4/driver-core-use-dev-argument-in-dev_dbg_ratelimited-stub.patch queue-4.4/modsign-hide-openssl-output-in-silent-builds.patch queue-4.4/net-hp100-remove-unnecessary-ifdefs.patch queue-4.4/genirq-msi-add-stubs-for-get_cached_msi_msg-pci_write_msi_msg.patch queue-4.4/asoc-intel-kconfig-fix-build-when-acpi-is-not-enabled.patch queue-4.4/asoc-ux500-add-module_license-tag.patch queue-4.4/wireless-cw1200-use-__maybe_unused-to-hide-pm-functions_.patch queue-4.4/mptfusion-hide-unused-seq_mpt_print_ioc_summary-function.patch queue-4.4/tlan-avoid-unused-label-with-pci-n.patch queue-4.4/usb-musb-ux500-remove-duplicate-check-for-dma_is_compatible.patch queue-4.4/mtd-cfi-enforce-valid-geometry-configuration.patch queue-4.4/thermal-spear-use-__maybe_unused-for-pm-functions.patch queue-4.4/x86-microcode-amd-change-load_microcode_amd-s-param-to-bool-to-fix-preemptibility-bug.patch queue-4.4/video-fbdev-mmp-add-module_license.patch queue-4.4/fbdev-sis-enforce-selection-of-at-least-one-backend.patch queue-4.4/x86-boot-avoid-warning-for-zero-filling-.bss.patch queue-4.4/power-bq27xxx_battery-mark-some-symbols-__maybe_unused.patch queue-4.4/scsi-mvumi-use-__maybe_unused-to-hide-pm-functions.patch queue-4.4/usb-phy-msm-add-regulator-dependency.patch queue-4.4/isdn-icn-remove-a-warning.patch queue-4.4/ncr5380-shut-up-gcc-indentation-warning.patch queue-4.4/arm64-dts-add-cooling-cells-to-cpu-nodes.patch queue-4.4/vmxnet3-prevent-building-with-64k-pages.patch queue-4.4/genksyms-fix-segfault-with-invalid-declarations.patch queue-4.4/x86-platform-add-pci-dependency-for-punit_atom_debug.patch queue-4.4/target-user-fix-cast-from-pointer-to-phys_addr_t.patch queue-4.4/rtlwifi-fix-gcc-6-indentation-warning.patch queue-4.4/alsa-hda-ca0132-fix-possible-null-pointer-use.patch queue-4.4/thermal-fix-intel_soc_dts_iosf_core-dependencies.patch queue-4.4/arm64-define-bug-instruction-without-config_bug.patch queue-4.4/v4l-remove-media_tuner-dependency-for-video_tuner.patch queue-4.4/tc358743-fix-register-i2c_rd-wr-functions.patch queue-4.4/scsi-fdomain-drop-fdomain_pci_tbl-when-built-in.patch queue-4.4/scsi-initio-remove-duplicate-module-device-table.patch queue-4.4/netlink-fix-nla_put_-u8-u16-u32-for-kasan.patch queue-4.4/x86-fpu-math-emu-fix-possible-uninitialized-variable-use.patch queue-4.4/asoc-rockchip-use-__maybe_unused-to-hide-st_irq_syscfg_resume.patch queue-4.4/staging-ste_rmi4-avoid-unused-function-warnings.patch queue-4.4/em28xx-only-use-mt9v011-if-camera-support-is-enabled.patch queue-4.4/pwc-hide-unused-label.patch queue-4.4/input-tca8418_keypad-hide-gcc-4.9-wmaybe-uninitialized-warning.patch queue-4.4/fbdev-sm712fb-avoid-unused-function-warnings.patch queue-4.4/isdn-sc-work-around-type-mismatch-warning.patch queue-4.4/tty-hvc_xen-hide-xen_console_remove-when-unused.patch queue-4.4/virtio_balloon-prevent-uninitialized-variable-use.patch queue-4.4/drm-nouveau-hide-gcc-4.9-wmaybe-uninitialized.patch queue-4.4/dell-wmi-dell-laptop-depends-dmi.patch queue-4.4/x86-add-multiuser-dependency-for-kvm.patch queue-4.4/md-avoid-warning-for-32-bit-sector_t.patch queue-4.4/isdn-eicon-reduce-stack-size-of-sig_ind-function.patch