WSL2-Linux-Kernel/drivers
Vladis Dronov 286d3250c9 efi: Fix a race and a buffer overflow while reading efivars via sysfs
There is a race and a buffer overflow corrupting a kernel memory while
reading an EFI variable with a size more than 1024 bytes via the older
sysfs method. This happens because accessing struct efi_variable in
efivar_{attr,size,data}_read() and friends is not protected from
a concurrent access leading to a kernel memory corruption and, at best,
to a crash. The race scenario is the following:

CPU0:                                CPU1:
efivar_attr_read()
  var->DataSize = 1024;
  efivar_entry_get(... &var->DataSize)
    down_interruptible(&efivars_lock)
                                     efivar_attr_read() // same EFI var
                                       var->DataSize = 1024;
                                       efivar_entry_get(... &var->DataSize)
                                         down_interruptible(&efivars_lock)
    virt_efi_get_variable()
    // returns EFI_BUFFER_TOO_SMALL but
    // var->DataSize is set to a real
    // var size more than 1024 bytes
    up(&efivars_lock)
                                         virt_efi_get_variable()
                                         // called with var->DataSize set
                                         // to a real var size, returns
                                         // successfully and overwrites
                                         // a 1024-bytes kernel buffer
                                         up(&efivars_lock)

This can be reproduced by concurrent reading of an EFI variable which size
is more than 1024 bytes:

  ts# for cpu in $(seq 0 $(nproc --ignore=1)); do ( taskset -c $cpu \
  cat /sys/firmware/efi/vars/KEKDefault*/size & ) ; done

Fix this by using a local variable for a var's data buffer size so it
does not get overwritten.

Fixes: e14ab23dde ("efivars: efivar_entry API")
Reported-by: Bob Sanders <bob.sanders@hpe.com> and the LTP testsuite
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200305084041.24053-2-vdronov@redhat.com
Link: https://lore.kernel.org/r/20200308080859.21568-24-ardb@kernel.org
2020-03-08 09:56:34 +01:00
..
accessibility
acpi ACPI fixes for 5.6-rc4 2020-02-28 09:02:18 -08:00
amba
android for-5.6/io_uring-vfs-2020-01-29 2020-01-29 18:53:37 -08:00
ata libata-5.6-2020-02-05 2020-02-06 06:11:50 +00:00
atm Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-01-28 16:02:33 -08:00
auxdisplay
base Revert "software node: Simplify software_node_release() function" 2020-03-04 22:31:44 +01:00
bcma Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-01-28 16:02:33 -08:00
block xen: branch for v5.6-rc5 2020-03-07 08:04:54 -06:00
bluetooth
bus bus: moxtet: fix potential stack buffer overflow 2020-02-15 10:33:19 -08:00
cdrom scsi: compat_ioctl: cdrom: Replace .ioctl with .compat_ioctl in four appropriate places 2020-02-24 15:06:07 -05:00
char tpm: Initialize crypto_id of allocated_banks to HASH_ALGO__LAST 2020-02-17 20:47:06 +02:00
clk ARM: SoC: late updates 2020-02-08 14:17:27 -08:00
clocksource ARM: SoC: late updates 2020-02-08 14:17:27 -08:00
connector
counter
cpufreq cpufreq: Fix policy initialization for internal governor drivers 2020-02-27 08:57:48 +01:00
cpuidle ARM: SoC-related driver updates 2020-02-08 14:04:19 -08:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-01-28 16:02:33 -08:00
dax
dca
devfreq Revert "PM / devfreq: Modify the device name as devfreq(X) for sysfs" 2020-02-24 11:14:29 +09:00
dio
dma dmaengine: imx-sdma: Fix the event id check to include RX event for UART6 2020-02-25 14:15:26 +05:30
dma-buf dma-buf: free dmabuf->name in dma_buf_release() 2020-02-27 18:01:58 +05:30
edac EDAC/sysfs: Remove csrow objects on errors 2020-02-13 13:29:41 +01:00
eisa
extcon
firewire
firmware efi: Fix a race and a buffer overflow while reading efivars via sysfs 2020-03-08 09:56:34 +01:00
fpga
fsi fsi: aspeed: add unspecified HAS_IOMEM dependency 2020-02-10 13:45:49 -08:00
gnss
gpio gpio: sifive: fix static checker warning 2020-02-10 13:54:17 +01:00
gpu Merge tag 'amd-drm-fixes-5.6-2020-03-05' of git://people.freedesktop.org/~agd5f/linux into drm-fixes 2020-03-06 11:06:33 +10:00
greybus
hid HID: hyperv: NULL check before some freeing functions is not needed. 2020-03-05 14:17:11 +00:00
hsi
hv - Most of the commits here are work to enable host-initiated hibernation 2020-02-03 14:42:03 +00:00
hwmon hwmon: (adt7462) Fix an error return in ADT7462_REG_VOLT() 2020-03-03 12:42:55 -08:00
hwspinlock
hwtracing
i2c i2c: altera: Fix potential integer overflow 2020-02-13 09:29:30 +01:00
i3c
ide scsi: compat_ioctl: cdrom: Replace .ioctl with .compat_ioctl in four appropriate places 2020-02-24 15:06:07 -05:00
idle intel_idle: Introduce 'states_off' module parameter 2020-02-03 11:57:18 +01:00
iio chrome platform changes for 5.6 2020-02-04 07:17:41 +00:00
infiniband Second RDMA 5.6 pull request 2020-03-07 19:52:55 -06:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2020-02-15 16:49:25 -08:00
interconnect
iommu iommu/arm-smmu: Restore naming of driver parameter prefix 2020-02-19 12:03:21 +01:00
ipack
irqchip irqchip/gic-v4.1: Avoid 64bit division for the sake of 32bit ARM 2020-02-09 15:47:37 -08:00
isdn proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
leds
lightnvm
macintosh macintosh: therm_windtunnel: fix regression when instantiating devices 2020-02-29 21:13:22 +01:00
mailbox
mcb
md block-5.6-2020-03-07 2020-03-07 14:14:38 -06:00
media media: mc-entity.c: use & to check pad flags, not == 2020-02-24 15:10:04 +01:00
memory
memstick
message
mfd chrome platform changes for 5.6 2020-02-04 07:17:41 +00:00
misc habanalabs: patched cb equals user cb in device memset 2020-02-11 11:12:47 +02:00
mmc ioremap changes for 5.6 2020-01-27 13:03:00 -08:00
mtd treewide: remove redundant IS_ERR() before error code check 2020-02-04 03:05:27 +00:00
mux
net net: dsa: mv88e6xxx: Fix masking of egress port 2020-02-27 12:29:09 -08:00
nfc nfc: pn544: Fix occasional HW initialization failure 2020-02-19 11:09:27 -08:00
ntb
nubus
nvdimm mm: Cleanup __put_devmap_managed_page() vs ->page_free() 2020-01-31 10:30:37 -08:00
nvme nvme-pci: Hold cq_poll_lock while completing CQEs 2020-02-28 01:32:14 +09:00
nvmem Merge branch 'i2c/for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2020-02-07 12:54:13 -08:00
of ARM: SoC-related driver updates 2020-02-08 14:04:19 -08:00
opp ioremap changes for 5.6 2020-01-27 13:03:00 -08:00
oprofile
parisc proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
parport
pci PCI: brcmstb: Fix build on 32bit ARM platforms with older compilers 2020-02-27 08:06:20 -06:00
pcmcia
perf drivers/perf: arm_pmu_acpi: Fix incorrect checking of gicc pointer 2020-03-02 12:07:35 +00:00
phy treewide: remove redundant IS_ERR() before error code check 2020-02-04 03:05:27 +00:00
pinctrl pinctrl: fix pxa2xx.c build warnings 2020-02-04 03:05:24 +00:00
platform platform/chrome: wilco_ec: Include asm/unaligned instead of linux/ path 2020-02-11 09:10:36 +01:00
pnp proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
power ARM: SoC platform updates 2020-02-08 13:55:25 -08:00
powercap
pps
ps3
ptp
pwm
rapidio
ras
regulator regulator: Fixes for v5.6 2020-03-06 14:48:30 -06:00
remoteproc
reset
rpmsg
rtc chrome platform changes for 5.6 2020-02-04 07:17:41 +00:00
s390 SCSI fixes on 20200229 2020-02-29 09:58:47 -06:00
sbus
scsi scsi: compat_ioctl: cdrom: Replace .ioctl with .compat_ioctl in four appropriate places 2020-02-24 15:06:07 -05:00
sfi
sh
siox
slimbus
soc soc/tegra: fuse: Fix build with Tegra194 configuration 2020-02-11 15:00:15 -08:00
soundwire
spi spi: Fixes for v5.6 2020-03-06 14:50:16 -06:00
spmi spmi: pmic-arb: Set lockdep class for hierarchical irq domains 2020-02-10 13:16:04 +01:00
ssb
staging media fixes for v5.6-rc5 2020-03-07 12:00:13 -06:00
target scsi: Revert "target: iscsi: Wait for all commands to finish before freeing a session" 2020-02-14 17:13:54 -05:00
tc The main MIPS changes for 5.6: 2020-01-31 11:28:31 -08:00
tee Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2020-02-24 11:40:23 -08:00
thermal - Fix a SEVERE docs build failure for cpu idle cooling device (Randy Dunlap) 2020-01-31 14:39:21 -08:00
thunderbolt thunderbolt: Prevent crash if non-active NVMem file is read 2020-02-13 04:59:30 -08:00
tty vt: selection, close sel_buffer race 2020-02-13 12:10:07 -08:00
uio
usb USB: misc: iowarrior: add support for the 100 device 2020-02-17 10:44:43 +01:00
vfio VFIO updates for v5.6-rc1 2020-02-03 22:22:05 +00:00
vhost vhost: Check docket sk_family instead of call getname 2020-02-22 21:41:42 -08:00
video vgacon: Fix a UAF in vgacon_invert_region 2020-03-06 21:06:34 +01:00
virt
virtio virtio_balloon: Fix memory leaks on errors in virtballoon_probe() 2020-02-06 03:40:27 -05:00
visorbus
vlynq
vme Char/Misc driver changes for 5.6-rc1 2020-01-29 10:35:54 -08:00
w1 Char/Misc driver changes for 5.6-rc1 2020-01-29 10:35:54 -08:00
watchdog ACPI fixes for 5.6-rc4 2020-02-28 09:02:18 -08:00
xen xen/xenbus: fix locking 2020-03-05 09:42:23 -06:00
zorro Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
Kconfig
Makefile