OpenCloudOS-Kernel/drivers
Jiri Kosina 09954bad44 floppy: refactor open() flags handling
In case /dev/fdX is open with O_NDELAY / O_NONBLOCK, floppy_open() immediately
succeeds, without performing any further media / controller preparations.
That's "correct" wrt. the NODELAY flag, but is hardly correct wrt. the rest
of the floppy driver, that is not really O_NONBLOCK ready, at all. Therefore
it's not too surprising, that subsequent attempts to work with the
filedescriptor produce bad results. Namely, syzkaller tool has been able
to livelock mmap() on the returned fd to keep waiting on the page unlock
bit forever.

Quite frankly, I have trouble defining what non-blocking behavior would be for
floppies. Is waiting ages for the driver to actually succeed reading a sector
blocking operation? Is waiting for drive motor to start blocking operation? How
about in case of virtualized floppies?

One option would be returning EWOULDBLOCK in case O_NDLEAY / O_NONBLOCK is
being passed to open(). That has a theoretical potential of breaking some
arcane and archaic userspace though.

Let's take a more conservative aproach, and accept the O_NDLEAY flag, and let
the driver behave as usual.

While at it, clean up a bit handling of !(mode & (FMODE_READ|FMODE_WRITE))
case and return EINVAL instead of succeeding as well.

Spotted by syzkaller tool.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-02-06 23:00:22 +01:00
..
accessibility
acpi Merge branches 'acpi-video' and 'acpi-hotplug' 2016-01-29 21:44:53 +01:00
amba
android
ata Merge branch 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata 2016-01-11 19:33:59 -08:00
atm
auxdisplay
base Merge branches 'pm-cpuidle', 'pm-cpufreq', 'pm-domains' and 'pm-sleep' 2016-01-29 21:45:17 +01:00
bcma GPIO bulk updates for the v4.5 kernel cycle: 2016-01-17 12:32:01 -08:00
block floppy: refactor open() flags handling 2016-02-06 23:00:22 +01:00
bluetooth
bus ARM: SoC driver updates for v4.5 2016-01-20 18:42:30 -08:00
cdrom
char Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-23 12:24:56 -08:00
clk ARM: DT updates for v4.5 2016-01-20 18:16:29 -08:00
clocksource ARM: SoC cleanups for v4.5 2016-01-20 17:55:20 -08:00
connector
cpufreq Merge branches 'pm-cpuidle', 'pm-cpufreq', 'pm-domains' and 'pm-sleep' 2016-01-29 21:45:17 +01:00
cpuidle Merge branches 'pm-cpuidle', 'pm-cpufreq', 'pm-domains' and 'pm-sleep' 2016-01-29 21:45:17 +01:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2016-01-22 11:58:43 -08:00
dca
devfreq PM / devfreq: Do not show statistics if it's not ready. 2016-01-13 17:30:33 +09:00
dio
dma dmaengine fixes for 4.5-rc1 2016-01-20 10:15:21 -08:00
dma-buf
edac
eisa
extcon
firewire
firmware UBSAN: run-time undefined behavior sanity checker 2016-01-20 17:09:18 -08:00
fmc
fpga
gpio ARM: SoC multiplatform code changes for v4.5 2016-01-20 18:03:56 -08:00
gpu Merge branch 'drm-rockchip-next-fixes-2016-01-22' of https://github.com/markyzq/kernel-drm-rockchip into drm-fixes 2016-01-29 10:04:29 +10:00
hid asm-generic changes for 4.5 2016-01-20 17:30:20 -08:00
hsi HSI: omap_ssi_port: fix handling of_get_named_gpio result 2016-01-07 16:07:54 +01:00
hv char/misc patches for 4.5-rc1 2016-01-13 10:23:36 -08:00
hwmon hwmon: (fam15h_power) Add bit masking for tdp_limit 2016-01-27 18:48:46 -08:00
hwspinlock
hwtracing
i2c Merge branch 'i2c/for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2016-01-14 11:25:37 -08:00
ide drivers/ide: make ide-scan-pci.c driver explicitly non-modular 2016-01-18 14:12:33 -05:00
idle
iio Merge branch 'akpm' (patches from Andrew) 2016-01-21 12:32:08 -08:00
infiniband Initial roundup of 4.5 merge window patches 2016-01-23 18:45:06 -08:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2016-01-22 17:20:30 -08:00
iommu iommu/amd: Correct the wrong setting of alias DTE in do_attach 2016-01-29 12:30:47 +01:00
ipack
irqchip Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-01-24 12:50:56 -08:00
isdn Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-01-11 23:55:43 -05:00
leds GPIO bulk updates for the v4.5 kernel cycle: 2016-01-17 12:32:01 -08:00
lguest lguest: Map switcher text R/O 2016-01-12 12:17:28 +01:00
lightnvm lightnvm: allow to force mm initialization 2016-02-04 09:19:45 -07:00
macintosh
mailbox
mcb
md Merge branch 'for-4.5/drivers' of git://git.kernel.dk/linux-block 2016-01-21 18:19:38 -08:00
media dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
memory ARM: SoC driver updates for v4.5 2016-01-20 18:42:30 -08:00
memstick memstick: use sector_div instead of do_div 2016-01-20 17:09:18 -08:00
message
mfd GPIO bulk updates for the v4.5 kernel cycle: 2016-01-17 12:32:01 -08:00
misc Merge branch 'akpm' (patches from Andrew) 2016-01-21 12:32:08 -08:00
mmc MMC core: 2016-01-22 12:04:21 -08:00
mtd Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-01-24 12:50:56 -08:00
net Initial roundup of 4.5 merge window patches 2016-01-23 18:45:06 -08:00
nfc
ntb NTB: Fix macro parameter conflict with field name 2016-01-21 19:53:10 -05:00
nubus
nvdimm mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup 2016-01-15 17:56:32 -08:00
nvme lightnvm: check overflow and correct mlc pairs 2016-02-04 09:19:45 -07:00
nvmem
of DeviceTree updates for 4.5: 2016-01-14 11:13:28 -08:00
oprofile wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
parisc parisc: convert to dma_map_ops 2016-01-20 17:09:18 -08:00
parport
pci Merge branches 'acpi-video' and 'acpi-hotplug' 2016-01-29 21:44:53 +01:00
pcmcia
perf
phy
pinctrl GPIO bulk updates for the v4.5 kernel cycle: 2016-01-17 12:32:01 -08:00
platform ideapad-laptop: Add Lenovo Yoga 700 to no_hw_rfkill dmi list 2016-01-24 10:15:01 -08:00
pnp
power power: bq27xxx_battery: Fix bq27541 AveragePower register address 2016-01-14 01:03:18 +01:00
powercap Merge branch 'powercap' 2016-01-12 01:12:40 +01:00
pps
ps3
ptp
pwm pwm: Mark all devices as "might sleep" 2016-01-21 15:04:59 +01:00
rapidio rapidio: use kobj_to_dev() 2016-01-20 17:09:18 -08:00
ras
regulator regulator: Update for v4.5 2016-01-15 12:14:47 -08:00
remoteproc virtio: make find_vqs() checkpatch.pl-friendly 2016-01-12 20:47:06 +02:00
reset
rpmsg virtio: make find_vqs() checkpatch.pl-friendly 2016-01-12 20:47:06 +02:00
rtc RTC for 4.5 2016-01-18 12:10:45 -08:00
s390 s390/cio: update measurement characteristics 2016-01-26 12:47:51 +01:00
sbus
scsi Merge remote-tracking branch 'mkp-scsi/4.5/scsi-fixes' into fixes 2016-01-26 17:44:42 -08:00
sfi
sh
sn
soc ARM: SoC support for Tegra platforms for v4.5 2016-01-22 17:30:52 -08:00
spi powerpc updates for 4.5 2016-01-15 13:18:47 -08:00
spmi
ssb
staging Initial roundup of 4.5 merge window patches 2016-01-23 18:45:06 -08:00
target Merge branch 'for-4.5/nvme' of git://git.kernel.dk/linux-block 2016-01-21 19:58:02 -08:00
tc
thermal Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2016-01-24 12:43:06 -08:00
thunderbolt
tty ARM: SoC driver updates for v4.5 2016-01-20 18:42:30 -08:00
uio
usb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-23 12:24:56 -08:00
uwb
vfio
vhost
video wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
virt
virtio virtio_pci: fix use after free on release 2016-01-26 10:18:28 +02:00
vlynq
vme
w1
watchdog watchdog: asm9260: remove __init and __exit annotations 2016-01-11 22:48:05 +01:00
xen Merge branch 'stable/for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/mm 2016-01-29 15:13:48 -08:00
zorro
Kconfig
Makefile