Kees Cook f4aacea2f5 sysctl: allow for strict write position handling ... When writing to a sysctl string, each write, regardless of VFS position, begins writing the string from the start. This means the contents of the last write to the sysctl controls the string contents instead of the first: open("/proc/sys/kernel/modprobe", O_WRONLY) = 1 write(1, "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"..., 4096) = 4096 write(1, "/bin/true", 9) = 9 close(1) = 0 $ cat /proc/sys/kernel/modprobe /bin/true Expected behaviour would be to have the sysctl be "AAAA..." capped at maxlen (in this case KMOD_PATH_LEN: 256), instead of truncating to the contents of the second write. Similarly, multiple short writes would not append to the sysctl. The old behavior is unlike regular POSIX files enough that doing audits of software that interact with sysctls can end up in unexpected or dangerous situations. For example, "as long as the input starts with a trusted path" turns out to be an insufficient filter, as what must also happen is for the input to be entirely contained in a single write syscall -- not a common consideration, especially for high level tools. This provides kernel.sysctl_writes_strict as a way to make this behavior act in a less surprising manner for strings, and disallows non-zero file position when writing numeric sysctls (similar to what is already done when reading from non-zero file positions). For now, the default (0) is to warn about non-zero file position use, but retain the legacy behavior. Setting this to -1 disables the warning, and setting this to 1 enables the file position respecting behavior. [akpm@linux-foundation.org: fix build] [akpm@linux-foundation.org: move misplaced hunk, per Randy] Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2014-06-06 16:08:13 -07:00
..
ABI	ACPI and power management updates for 3.16-rc1	2014-06-04 08:57:16 -07:00
accounting
acpi	Documentation / ACPI: Fix location of GPIO documentation	2014-05-23 14:39:26 +02:00
aoe
arm	Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm into next	2014-06-05 15:57:04 -07:00
arm64	doc: arm64: add description of EFI stub support	2014-04-30 19:57:05 +01:00
auxdisplay
backlight
blackfin	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
block	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
blockdev	zram: propagate error to user	2014-04-07 16:36:02 -07:00
bus-devices
cdrom
cgroups	Documentation/memcg: warn about incomplete kmemcg state	2014-06-04 16:54:00 -07:00
connector	w1: optional bundling of netlink kernel replies	2014-05-27 13:56:21 -07:00
console
cpu-freq	PM / OPP: Move cpufreq specific OPP functions out of generic OPP library	2014-05-07 00:39:03 +02:00
cpuidle
cris
crypto
development-process
device-mapper	dm thin: add 'no_space_timeout' dm-thin-pool module param	2014-05-20 14:30:36 -04:00
devicetree	drivers/rtc/rtc-hym8563.c: add optional clock-output-names property	2014-06-06 16:08:08 -07:00
DocBook	Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media into next	2014-06-04 14:24:30 -07:00
driver-model	Staging driver patches for 3.16-rc1	2014-06-03 08:34:00 -07:00
dvb	Linux 3.14-rc5	2014-03-11 06:55:49 -03:00
early-userspace
EDID
extcon	extcon: fix switch class porting guide (Documentation)	2014-01-07 11:54:28 +09:00
fault-injection
fb	doc: spelling error changes	2014-05-05 15:32:05 +02:00
filesystems	Documentation/filesystems/seq_file.txt: create_proc_entry deprecated	2014-06-06 16:08:11 -07:00
firmware_class
fmc	FMC: make eeprom attribute writable	2014-02-28 15:12:08 -08:00
frv
gpio	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
hid	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
hwmon	New driver for NCT6683D	2014-06-03 11:09:43 -07:00
i2c	Documentation: i2c: improve section about flags mangling the protocol	2014-04-06 13:53:48 +02:00
i2o
ia64
ide	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
infiniband
input	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
ioctl	s390/hypfs: add interface for diagnose 0x304	2014-01-24 09:40:59 +01:00
isdn
ja_JP	Documentation: Update stable address in Chinese and Japanese translations	2014-04-16 14:13:27 -07:00
kbuild	kconfig: make allnoconfig disable options behind EMBEDDED and EXPERT	2014-04-07 16:36:09 -07:00
kdump
ko_KR	Documentation: HOWTO: Updates on subsystem trees, patchwork, -next (vs. -mm) in ko_KR	2014-01-08 15:32:51 -08:00
laptops	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
leds	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
m68k	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
make
memory-devices
metag
mic	misc: mic: Fix endianness issues.	2013-11-27 11:03:38 -08:00
mips
misc-devices	Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging	2014-01-29 18:56:27 -08:00
mmc
mn10300
mtd	doc: spelling error changes	2014-05-05 15:32:05 +02:00
namespaces
netlabel
networking	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
nfc
parisc
PCI	Merge branch 'pci/dead-code' into next	2014-02-20 14:32:34 -07:00
pcmcia
phy	phy: Add new Exynos USB 2.0 PHY driver	2014-03-08 12:39:44 +05:30
power	Merge branch 'pm-cpufreq'	2014-06-03 23:13:20 +02:00
powerpc	doc: spelling error changes	2014-05-05 15:32:05 +02:00
pps
prctl
pti
ptp	ptp: Fix compiler warnings in the testptp utility	2014-03-27 14:51:47 -04:00
rapidio	rapidio: rework device hierarchy and introduce mport class of devices	2014-04-07 16:36:07 -07:00
RCU	documentation: Update API documentation	2014-04-29 08:38:53 -07:00
s390	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
scheduler	asm/system.h: clean asm/system.h from docs	2014-04-07 16:36:11 -07:00
scsi	[SCSI] megaraid_sas: Version and Changelog update	2014-03-15 10:19:21 -07:00
security	doc: spelling error changes	2014-05-05 15:32:05 +02:00
serial	tty/serial: Add GPIOLIB helpers for controlling modem lines	2014-05-28 12:49:14 -07:00
sh
sound	doc: spelling error changes	2014-05-05 15:32:05 +02:00
spi	Merge remote-tracking branches 'spi/topic/s3c64xx', 'spi/topic/sc18is602', 'spi/topic/sh-hspi', 'spi/topic/sh-msiof', 'spi/topic/sh-sci', 'spi/topic/sirf' and 'spi/topic/spidev' into spi-next	2014-03-30 00:51:34 +00:00
sysctl	sysctl: allow for strict write position handling	2014-06-06 16:08:13 -07:00
target
thermal
timers	timer_stats/doc: Fix /proc/timer_stats documentation	2014-05-04 20:46:32 +02:00
tpm
trace	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
usb	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
vDSO
video4linux	[media] exynos4-is: Remove support for non-dt platforms	2014-05-23 18:52:54 -03:00
virtual	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
vm	mm/memory-failure.c: support use of a dedicated thread to handle SIGBUS(BUS_MCEERR_AO)	2014-06-04 16:54:13 -07:00
w1	w1: optional bundling of netlink kernel replies	2014-05-27 13:56:21 -07:00
watchdog	watchdog: it87_wdt: Work around non-working CIR interrupts	2014-03-31 13:33:55 +02:00
wimax
x86	Merge branch 'x86/espfix' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next	2014-06-05 07:46:15 -07:00
xtensa	xtensa: remap io area defined in device tree	2014-01-15 00:25:14 +04:00
zh_CN	driver core fixes for 3.15-rc2	2014-04-18 16:59:52 -07:00
.gitignore
00-INDEX	Merge branch 'x86-nuke-platforms-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-04-02 13:15:58 -07:00
applying-patches.txt
assoc_array.txt	KEYS: Fix multiple key add into associative array	2013-12-02 11:24:18 +00:00
atomic_ops.txt	arch,doc: Convert smp_mb__*()	2014-04-18 14:20:48 +02:00
bad_memory.txt
basic_profiling.txt
bcache.txt
binfmt_misc.txt
braille-console.txt
bt8xxgpio.txt
btmrvl.txt
BUG-HUNTING
bus-virt-phys-mapping.txt
cachetlb.txt
Changes	doc: Note need of bc in the kernel build from 3.10 onwards	2014-05-19 16:27:20 +02:00
circular-buffers.txt	documentation: Update circular buffer for load-acquire/store-release	2013-12-03 10:08:57 -08:00
clk.txt	Documentation: clk: Add locking documentation	2014-03-19 14:56:06 -07:00
coccinelle.txt
CodingStyle	Documentation: expand/clarify debug documentation	2014-06-04 16:54:17 -07:00
cpu-hotplug.txt	Doc/cpu-hotplug: Specify race-free way to register CPU hotplug callbacks	2014-03-20 13:43:40 +01:00
cpu-load.txt
cputopology.txt
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt	firewire: revert to 4 GB RDMA, fix protocols using Memory Space	2014-05-29 15:50:30 +02:00
dell_rbu.txt
devices.txt	Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media	2014-04-04 09:50:07 -07:00
digsig.txt
DMA-API-HOWTO.txt	DMA-API: Update dma_pool_create ()and dma_pool_alloc() descriptions	2014-05-26 17:28:28 -06:00
DMA-API.txt	DMA-API: Capitalize "CPU" consistently	2014-05-26 17:28:27 -06:00
DMA-attributes.txt	doc: spelling error changes	2014-05-05 15:32:05 +02:00
dma-buf-sharing.txt	doc: spelling error changes	2014-05-05 15:32:05 +02:00
DMA-ISA-LPC.txt	DMA-API: Clarify physical/bus address distinction	2014-05-20 16:54:21 -06:00
dmaengine.txt
dmatest.txt	dmatest: add a 'wait' parameter	2013-11-14 11:04:40 -08:00
dontdiff	Documentation: LLVMLinux: Update Documentation/dontdiff	2014-04-09 13:44:34 -07:00
dynamic-debug-howto.txt	doc: spelling error changes	2014-05-05 15:32:05 +02:00
edac.txt	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
efi-stub.txt	doc: arm64: add description of EFI stub support	2014-04-30 19:57:05 +01:00
eisa.txt
email-clients.txt	Documentation: update thunderbird email client settings	2014-05-25 12:39:00 -07:00
flexible-arrays.txt
futex-requeue-pi.txt	doc: fix double words	2014-03-21 13:16:58 +01:00
gcov.txt
highuid.txt
HOWTO	Documentation: HOWTO: Update broken links to tpp	2013-12-10 23:09:08 -08:00
hsi.txt	Documentation: HSI: Add some general description for the HSI subsystem	2014-05-04 09:49:46 +02:00
hw_random.txt
hwspinlock.txt
init.txt
initrd.txt
intel_txt.txt
Intel-IOMMU.txt
io_ordering.txt
io-mapping.txt	doc: fix some typos	2013-12-02 14:48:28 +01:00
iostats.txt
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt	genirq: Improve documentation to match current implementation	2014-05-27 10:16:44 +02:00
IRQ.txt
irqflags-tracing.txt	asm/system.h: clean asm/system.h from docs	2014-04-07 16:36:11 -07:00
isapnp.txt
java.txt	Documentation: update java sample wrapper for java 7	2014-05-25 12:39:00 -07:00
kernel-doc-nano-HOWTO.txt
kernel-docs.txt
kernel-parameters.txt	kernel/panic.c: add "crash_kexec_post_notifiers" option for kdump after panic_notifers	2014-06-06 16:08:12 -07:00
kernel-per-CPU-kthreads.txt	Documentation/kernel-per-CPU-kthreads.txt: Workqueue affinity	2014-02-17 14:56:08 -08:00
kmemcheck.txt	doc: fix double words	2014-03-21 13:16:58 +01:00
kmemleak.txt	Documentation/kmemleak.txt: updates	2014-04-03 16:21:27 -07:00
kobject.txt	kobject: remove kset from sysfs immediately in kset_unregister()	2013-12-07 21:20:11 -08:00
kprobes.txt
kref.txt
ldm.txt
local_ops.txt
lockdep-design.txt
lockstat.txt
lockup-watchdogs.txt
logo.gif
logo.txt
magic-number.txt	Documentation/serial: Delete obsolete driver documentation	2014-04-16 14:20:34 -07:00
Makefile
ManagementStyle
md.txt	doc: fix some typos in documentations	2013-12-02 14:45:19 +01:00
media-framework.txt
memory-barriers.txt	Documentation/memory-barriers.txt: fix important typo re memory barriers	2014-06-06 16:08:11 -07:00
memory-hotplug.txt	memory-hotplug: update documentation to hide information about SECTIONS and remove end_phys_index	2014-06-04 16:53:58 -07:00
module-signing.txt	Nothing major: the stricter permissions checking for sysfs broke	2014-04-06 09:38:07 -07:00
mono.txt
mutex-design.txt
nommu-mmap.txt
numastat.txt
oops-tracing.txt	Use 'E' instead of 'X' for unsigned module taint flag.	2014-03-31 14:52:43 +10:30
padata.txt
parport-lowlevel.txt
parport.txt
percpu-rw-semaphore.txt
phy.txt	drivers: phy: Add support for optional phys	2014-02-05 05:48:43 +00:00
pi-futex.txt
pinctrl.txt	pinctrl: Fix some typos and grammar issues in the documentation	2014-01-15 13:59:50 +01:00
pnp.txt
preempt-locking.txt
printk-formats.txt	doc: printk-formats: do not mention casts for u64/s64	2014-05-05 15:32:42 +02:00
pwm.txt
ramoops.txt
rbtree.txt	doc: spelling error changes	2014-05-05 15:32:05 +02:00
remoteproc.txt
rfkill.txt	doc: spelling error changes	2014-05-05 15:32:05 +02:00
robust-futex-ABI.txt	Documentation/robust-futex-API: Count properly to 4	2013-11-30 14:08:28 +01:00
robust-futexes.txt	doc: spelling error changes	2014-05-05 15:32:05 +02:00
rpmsg.txt
rt-mutex-design.txt	doc: fix some typos in documentations	2013-12-02 14:45:19 +01:00
rt-mutex.txt
rtc.txt
SAK.txt
SecurityBugs
serial-console.txt
sgi-ioc4.txt
SM501.txt
smsc_ece1099.txt
sparse.txt
spinlocks.txt
stable_api_nonsense.txt
stable_kernel_rules.txt	stable_kernel_rules: spelling/word usage	2014-04-16 14:13:26 -07:00
static-keys.txt	doc: fix some typos in documentations	2013-12-02 14:45:19 +01:00
SubmitChecklist
SubmittingDrivers
SubmittingPatches	Documentation/SubmittingPatches: describe the Fixes: tag	2014-06-06 16:08:11 -07:00
svga.txt
sysfs-rules.txt
sysrq.txt
this_cpu_ops.txt
unaligned-memory-access.txt	ether_addr_equal: Optimize implementation, remove unused compare_ether_addr	2013-12-06 16:37:43 -05:00
unicode.txt
unshare.txt
vfio.txt
VGA-softcursor.txt
vgaarbiter.txt
video-output.txt
vme_api.txt	VME: Rename vme_slot_get to avoid confusion with reference counting	2013-12-03 11:15:58 -08:00
volatile-considered-harmful.txt
workqueue.txt
ww-mutex-design.txt
xz.txt
zorro.txt	zorro/UAPI: Disintegrate include/linux/zorro*.h	2013-11-26 11:09:08 +01:00