linux/drivers/misc
Marco Elver 941faf832d UPSTREAM: lkdtm: disable KASAN for rodata.o
[ Upstream commit 6d5a88cd0c ]

Building lkdtm with KASAN and Clang 11 or later results in the following
error when attempting to load the module:

  kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
  BUG: unable to handle page fault for address: ffffffffc019cd70
  #PF: supervisor instruction fetch in kernel mode
  #PF: error_code(0x0011) - permissions violation
  ...
  RIP: 0010:asan.module_ctor+0x0/0xffffffffffffa290 [lkdtm]
  ...
  Call Trace:
   do_init_module+0x17c/0x570
   load_module+0xadee/0xd0b0
   __x64_sys_finit_module+0x16c/0x1a0
   do_syscall_64+0x34/0x50
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

The reason is that rodata.o generates a dummy function that lives in
.rodata to validate that .rodata can't be executed; however, Clang 11 adds
KASAN globals support by generating module constructors to initialize
globals redzones.  When Clang 11 adds a module constructor to rodata.o, it
is also added to .rodata: any attempt to call it on initialization results
in the above error.

Therefore, disable KASAN instrumentation for rodata.o.

Link: https://lkml.kernel.org/r/20201214191413.3164796-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bug: 172318110
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Change-Id: I0a3662322bac8961b0f87ab5e8e87acfb1ac3ec5
2021-01-19 21:47:27 -08:00
..
altera-stapl
c2port
cardreader
cb710
cxl
echo
eeprom
genwqe
habanalabs
ibmasm
lis3lv02d
lkdtm UPSTREAM: lkdtm: disable KASAN for rodata.o 2021-01-19 21:47:27 -08:00
mei
ocxl
sgi-gru
sgi-xp
ti-st
uacce
vmw_vmci
ad525x_dpot-i2c.c
ad525x_dpot-spi.c
ad525x_dpot.c
ad525x_dpot.h
apds990x.c
apds9802als.c
atmel_tclib.c
atmel-ssc.c
bh1770glc.c
cs5535-mfgpt.c
ds1682.c
dummy-irq.c
enclosure.c
fastrpc.c
hisi_hikey_usb.c
hmc6352.c
hpilo.c
hpilo.h
ibmvmc.c
ibmvmc.h
ics932s401.c
isl29003.c
isl29020.c
Kconfig
kgdbts.c
lattice-ecp3-config.c
Makefile
pch_phub.c
pci_endpoint_test.c
phantom.c
pti.c
pvpanic.c
qcom-coincell.c
sram-exec.c
sram.c
sram.h
tifm_7xx1.c
tifm_core.c
tsl2550.c
uid_sys_stats.c
vmw_balloon.c
xilinx_sdfec.c