linux/drivers/firmware
Arend van Spriel ab2180a15c firmware/efi: Add NULL pointer checks in efivars API functions
Since commit:

   ce2e6db554 ("brcmfmac: Add support for getting nvram contents from EFI variables")

we have a device driver accessing the efivars API. Several functions in
the efivars API assume __efivars is set, i.e., that they will be accessed
only after efivars_register() has been called. However, the following NULL
pointer access was reported calling efivar_entry_size() from the brcmfmac
device driver:

  Unable to handle kernel NULL pointer dereference at virtual address 00000008
  pgd = 60bfa5f1
  [00000008] *pgd=00000000
  Internal error: Oops: 5 [#1] SMP ARM
  ...
  Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
  Workqueue: events request_firmware_work_func
  PC is at efivar_entry_size+0x28/0x90
  LR is at brcmf_fw_complete_request+0x3f8/0x8d4 [brcmfmac]
  pc : [<c0c40718>]    lr : [<bf2a3ef4>]    psr: a00d0113
  sp : ede7fe28  ip : ee983410  fp : c1787f30
  r10: 00000000  r9 : 00000000  r8 : bf2b2258
  r7 : ee983000  r6 : c1604c48  r5 : ede7fe88  r4 : edf337c0
  r3 : 00000000  r2 : 00000000  r1 : ede7fe88  r0 : c17712c8
  Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
  Control: 10c5387d  Table: ad16804a  DAC: 00000051

Disassembly showed that the local static variable __efivars is NULL,
which is not entirely unexpected given that it is a non-EFI platform.

So add a NULL pointer check to efivar_entry_size(), and to related
functions while at it. In efivars_register() a couple of sanity checks
are added as well.

Reported-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Snowberg <eric.snowberg@oracle.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Julien Thierry <julien.thierry@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: YiFei Zhu <zhuyifei1999@gmail.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181129171230.18699-9-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-11-30 09:06:32 +01:00
..
arm_scmi firmware: arm_scmi: add a getter for power of performance states 2018-09-10 17:37:06 +01:00
broadcom firmware: bcm47xx_nvram: Support small (0x6000 B) NVRAM partitions 2018-04-23 16:39:35 +01:00
efi firmware/efi: Add NULL pointer checks in efivars API functions 2018-11-30 09:06:32 +01:00
google gsmi: Add GSMI commands to log S0ix info 2018-10-15 20:32:26 +02:00
imx firmware: imx: add misc svc support 2018-10-08 22:09:09 +08:00
meson firmware: meson_sm: Add serial number sysfs entry 2018-09-12 20:54:07 -07:00
tegra firmware: tegra: bpmp: Implement suspend/resume support 2018-10-10 16:47:22 +02:00
xilinx firmware: xilinx: Add zynqmp IOCTL API for device control 2018-10-09 13:26:21 +02:00
arm_scpi.c treewide: devm_kzalloc() -> devm_kcalloc() 2018-06-12 16:19:22 -07:00
arm_sdei.c firmware: arm_sdei: Fix return value check in sdei_present_dt() 2018-01-15 18:16:59 +00:00
dmi_scan.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
dmi-id.c firmware: dmi: Add access to the SKU ID string 2018-06-17 14:09:42 +02:00
dmi-sysfs.c firmware: dmi: handle missing DMI data gracefully 2018-02-03 11:25:20 +01:00
edd.c edd: don't spam log if no EDD information is present 2018-03-27 09:51:23 +02:00
iscsi_ibft_find.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
iscsi_ibft.c ibft: Deprecate pci_get_bus_and_slot() 2018-01-11 17:26:55 -06:00
Kconfig platform-drivers-x86 for v4.20-1 2018-11-01 08:42:21 -07:00
Makefile platform-drivers-x86 for v4.20-1 2018-11-01 08:42:21 -07:00
memmap.c memblock: stop using implicit alignment to SMP_CACHE_BYTES 2018-10-31 08:54:16 -07:00
pcdp.c
pcdp.h
psci_checker.c drivers/firmware: psci_checker: stash and use topology_core_cpumask for hotplug tests 2018-07-26 00:16:58 -07:00
psci.c firmware/psci: Expose SMCCC version through psci_ops 2018-02-06 22:54:11 +00:00
qcom_scm-32.c firmware: qcom: scm: Fix crash in qcom_scm_call_atomic1() 2018-05-24 22:36:45 -05:00
qcom_scm-64.c
qcom_scm.c firmware: qcom: scm: Refactor clock handling 2018-09-14 00:31:52 -05:00
qcom_scm.h
qemu_fw_cfg.c media: headers: fix linux/mod_devicetable.h inclusions 2018-08-02 18:30:54 -04:00
raspberrypi.c firmware: raspberrypi: Remove VLA usage 2018-07-09 10:47:29 -07:00
scpi_pm_domain.c firmware: Convert to using %pOFn instead of device_node.name 2018-10-04 14:16:01 -05:00
ti_sci.c firmware: ti_sci: Provide host-id as an optional dt parameter 2018-08-28 13:22:13 -07:00
ti_sci.h firmware: ti_sci: Switch to SPDX Licensing 2018-05-04 23:10:23 -07:00