Petr Mladek 3e5903eb9c vsprintf: Prevent crash when dereferencing invalid pointers ... We already prevent crash when dereferencing some obviously broken pointers. But the handling is not consistent. Sometimes we print "(null)" only for pure NULL pointer, sometimes for pointers in the first page and sometimes also for pointers in the last page (error codes). Note that printk() call this code under logbuf_lock. Any recursive printks are redirected to the printk_safe implementation and the messages are stored into per-CPU buffers. These buffers might be eventually flushed in printk_safe_flush_on_panic() but it is not guaranteed. This patch adds a check using probe_kernel_read(). It is not a full-proof test. But it should help to see the error message in 99% situations where the kernel would silently crash otherwise. Also it makes the error handling unified for "%s" and the many %p* specifiers that need to read the data from a given address. We print: + (null) when accessing data on pure pure NULL address + (efault) when accessing data on an invalid address It does not affect the %p* specifiers that just print the given address in some form, namely %pF, %pf, %pS, %ps, %pB, %pK, %px, and plain %p. Note that we print (efault) from security reasons. In fact, the real address can be seen only by %px or eventually %pK. Link: http://lkml.kernel.org/r/20190417115350.20479-9-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>		2019-04-26 16:20:43 +02:00
..
ABI	- New Drivers	2019-03-08 10:02:58 -08:00
accelerators
accounting	psi: cgroup support	2018-10-26 16:26:32 -07:00
acpi	ACPI / tables: table override from built-in initrd	2019-01-14 11:42:18 +01:00
admin-guide	Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2019-03-07 11:44:01 -08:00
aoe
arm	Documentation: Use "while" instead of "whilst"	2018-11-20 09:30:43 -07:00
arm64	clocksource/drivers/arch_timer: Workaround for Allwinner A64 timer instability	2019-02-23 12:13:45 +01:00
auxdisplay
backlight
block	block: document usage of bio iterator helpers	2019-02-15 08:40:12 -07:00
blockdev	zram: idle writeback fixes and cleanup	2019-01-08 17:15:10 -08:00
bpf	docs/bpf: minor casing/punctuation fixes	2019-03-02 00:40:04 +01:00
bus-devices
cdrom
cgroup-v1	Merge branch 'for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2019-03-07 10:11:41 -08:00
cma
connector
console
core-api	vsprintf: Prevent crash when dereferencing invalid pointers	2019-04-26 16:20:43 +02:00
cpu-freq	Documentation: cpu-freq: Frequencies aren't always sorted	2018-11-07 13:29:04 +01:00
crypto	crypto: skcipher - remove remnants of internal IV generators	2018-12-23 11:52:45 +08:00
dev-tools	A fairly normal cycle for documentation stuff. We have a new	2018-12-29 11:21:49 -08:00
device-mapper	Documentation: Use "while" instead of "whilst"	2018-11-20 09:30:43 -07:00
devicetree	This is the bulk of GPIO changes for the v5.1 cycle:	2019-03-08 10:09:53 -08:00
doc-guide	doc:process: add links where missing	2018-12-06 10:21:19 -07:00
driver-api	This is the bulk of GPIO changes for the v5.1 cycle:	2019-03-08 10:09:53 -08:00
driver-model	Documentation: driver core: remove use of BUS_ATTR	2019-01-08 15:17:45 +01:00
early-userspace	Correct gen_init_cpio tool's documentation	2018-11-25 12:25:53 -07:00
EDID	Docs/EDID: Calculate CRC while building the code	2018-11-06 07:36:22 -07:00
extcon
fault-injection
fb	fbdev: fbmem: convert CONFIG_FB_LOGO_CENTER into a cmd line option	2019-01-16 17:42:35 +01:00
features	Documentation/features: Add csky kernel features	2019-01-07 22:22:16 +08:00
filesystems	for-5.1/block-20190302	2019-03-08 14:12:17 -08:00
firmware_class
fmc
fpga
gpio
gpu	Merge drm/drm-next into drm-misc-next	2019-02-11 10:35:35 +01:00
hid	HID: doc: fix wrong data structure reference for UHID_OUTPUT	2018-12-18 14:55:22 +01:00
hwmon	hwmon: (lm85) add support for LM96000 high frequencies	2019-02-18 14:23:29 -08:00
i2c	i2c: gpio: fault-injector: add 'inject_panic' injector	2019-02-23 10:34:08 +01:00
ia64
ide
iio
infiniband
input	Input: add REL_WHEEL_HI_RES and REL_HWHEEL_HI_RES	2018-12-07 16:27:11 +01:00
interconnect	interconnect: Add generic on-chip interconnect API	2019-01-22 13:37:25 +01:00
ioctl	seccomp: add a return code to trap to userspace	2018-12-11 16:28:41 -08:00
isdn
kbuild	kbuild: generate asm-generic wrappers if mandatory headers are missing	2019-01-06 09:46:51 +09:00
kdump	kdump: Document kernel data exported in the vmcoreinfo note	2019-01-15 11:05:28 +01:00
kernel-hacking
laptops	platform-drivers-x86 for v4.20-1	2018-11-01 08:42:21 -07:00
leds	Documentation: Use "while" instead of "whilst"	2018-11-20 09:30:43 -07:00
lightnvm
livepatch	livepatch: Remove signal sysfs attribute	2019-01-16 22:09:33 +01:00
locking	This is a fairly typical cycle for documentation. There's some welcome	2018-10-24 18:01:11 +01:00
m68k
maintainer
md
media	A fairly normal cycle for documentation stuff. We have a new	2018-12-29 11:21:49 -08:00
memory-devices
mic
mips
misc-devices
mmc
mtd
namespaces
netlabel
networking	Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next	2019-03-04 10:14:31 -08:00
nfc
nios2
nvdimm	libnvdimm/security: Add documentation for nvdimm security support	2018-12-21 12:44:41 -08:00
nvmem
openrisc
parisc
PCI	pci-v4.20-changes	2018-10-25 06:50:48 -07:00
pcmcia
perf	Documentation: perf: Add documentation for ThunderX2 PMU uncore driver	2018-12-06 12:29:47 +00:00
phy
platform
power	PM/EM: Document the Energy Model framework	2019-01-27 12:29:37 +01:00
powerpc	powerpc/fadump: Reservationless firmware assisted dump	2018-12-21 11:32:49 +11:00
pps
process	configs: get rid of obsolete CONFIG_ENABLE_WARN_DEPRECATED	2019-03-07 18:32:02 -08:00
pti
ptp
rapidio
RCU	Merge branches 'doc.2019.01.26a', 'fixes.2019.01.26a', 'sil.2019.01.26a', 'spdx.2019.02.09a', 'srcu.2019.01.26a' and 'torture.2019.01.26a' into HEAD	2019-02-09 08:47:52 -08:00
riscv
s390	Documentation: Use "while" instead of "whilst"	2018-11-20 09:30:43 -07:00
scheduler	sched/doc: Document Energy Aware Scheduling	2019-01-27 12:29:37 +01:00
scsi	SCSI misc on 20181224	2018-12-28 14:48:06 -08:00
security	Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2019-01-02 09:43:14 -08:00
serial	Documentation: Use "while" instead of "whilst"	2018-11-20 09:30:43 -07:00
sh	sh: remove board_time_init() callback	2018-12-18 16:13:04 +01:00
sound	ASoC: More changes for v5.1	2019-02-28 13:30:55 +01:00
sparc
sphinx
sphinx-static
spi	pxa2xx: replace spi_master with spi_controller	2019-01-23 10:59:56 +00:00
sysctl	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2019-03-06 08:14:05 -08:00
target
thermal	Documentation: Use "while" instead of "whilst"	2018-11-20 09:30:43 -07:00
timers
trace	Merge branches 'pm-cpuidle', 'pm-cpufreq' and 'pm-sleep'	2019-01-11 10:09:51 +01:00
translations	configs: get rid of obsolete CONFIG_ENABLE_WARN_DEPRECATED	2019-03-07 18:32:02 -08:00
usb	usb: core: add option of only authorizing internal devices	2019-02-22 09:27:55 +01:00
userspace-api	x86/speculation: Add PR_SPEC_DISABLE_NOEXEC	2019-01-29 22:11:49 +01:00
virtual	Documentation/virtual/kvm: Update URL for AMD SEV API specification	2019-01-11 18:38:07 +01:00
vm	A fairly normal cycle for documentation stuff. We have a new	2018-12-29 11:21:49 -08:00
w1
watchdog	watchdog: docs: kernel-api: don't reference removed functions	2018-12-24 13:15:06 +01:00
wimax
x86	x86/resctrl: Avoid confusion over the new X86_RESCTRL config	2019-02-02 10:34:52 +01:00
xilinx	Documentation: xilinx: Add documentation for eemi APIs	2018-10-09 13:26:05 +02:00
xtensa	xtensa: document boot parameter passing	2019-02-03 18:06:19 -08:00
.gitignore
atomic_bitops.txt
atomic_t.txt
bt8xxgpio.txt
btmrvl.txt
bus-virt-phys-mapping.txt
Changes
clearing-warn-once.txt
CodingStyle
conf.py	This is a fairly typical cycle for documentation. There's some welcome	2018-10-24 18:01:11 +01:00
cpu-load.txt
cputopology.txt
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt
dell_rbu.txt
digsig.txt
DMA-API-HOWTO.txt
DMA-API.txt	dma-mapping: deprecate dma_zalloc_coherent	2018-12-20 08:14:09 +01:00
DMA-attributes.txt
DMA-ISA-LPC.txt
docutils.conf
dontdiff	kernel/configs: use .incbin directive to embed config_data.gz	2019-03-07 18:32:02 -08:00
efi-stub.txt
eisa.txt
flexible-arrays.txt
futex-requeue-pi.txt
gcc-plugins.txt
highuid.txt
hw_random.txt
hwspinlock.txt
index.rst
intel_txt.txt
Intel-IOMMU.txt
io_ordering.txt
io-mapping.txt
iostats.txt
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt
IRQ.txt
irqflags-tracing.txt
isa.txt
isapnp.txt
kernel-per-CPU-kthreads.txt
kobject.txt	kref/kobject: Improve documentation	2018-12-06 13:57:03 +01:00
kprobes.txt
kref.txt
ldm.txt
lockup-watchdogs.txt
logo.gif
logo.txt
lsm.txt
lzo.txt	lib/lzo: separate lzo-rle from lzo	2019-03-07 18:32:03 -08:00
mailbox.txt
Makefile	kbuild: Add support for DT binding schema checks	2018-12-13 09:41:32 -06:00
memory-barriers.txt	Documentation: Use "while" instead of "whilst"	2018-11-20 09:30:43 -07:00
men-chameleon-bus.txt
nommu-mmap.txt
ntb.txt
numastat.txt
padata.txt
parport-lowlevel.txt
percpu-rw-semaphore.txt
phy.txt
pi-futex.txt
pnp.txt
preempt-locking.txt	Documentation: preempt-locking: Use better example	2018-10-12 11:35:47 -06:00
pwm.txt
rbtree.txt
remoteproc.txt
rfkill.txt
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
rtc.txt
SAK.txt
sgi-ioc4.txt
siphash.txt
SM501.txt
smsc_ece1099.txt
speculation.txt
static-keys.txt	Documentation: Use "while" instead of "whilst"	2018-11-20 09:30:43 -07:00
SubmittingPatches
svga.txt
switchtec.txt	NTB: switchtec_ntb: Update switchtec documentation with prerequisites for NTB	2018-10-11 11:28:53 -05:00
sync_file.txt
tee.txt
this_cpu_ops.txt
unaligned-memory-access.txt
vfio-mediated-device.txt
vfio.txt
video-output.txt
xillybus.txt
xz.txt
zorro.txt