linux/drivers
Jiri Slaby b81273a132 TTY: do not reset master's packet mode
Now that login from util-linux is forced to drop all references to a
TTY which it wants to hangup (to reach reference count 1) we are
seeing issues with telnet. When login closes its last reference to the
slave PTY, it also resets packet mode on the *master* side. And we
have a race here.

What telnet does is fork+exec of `login'. Then there are two
scenarios:
* `login' closes the slave TTY and resets thus master's packet mode,
  but even now telnet properly sets the mode, or
* `telnetd' sets packet mode on the master, `login' closes the slave
  TTY and resets master's packet mode.

The former case is OK. However the latter happens in much more cases,
by the order of magnitude to be precise. So when one tries to login to
such a messed telnet setup, they see the following:
inux login:
            ogin incorrect

Note the missing first letters -- telnet thinks it is still in the
packet mode, so when it receives "linux login" from `login', it
considers "l" as the type of the packet and strips it.

SuS does not mention how the implementation should behave. Both BSDs I
checked (Free and Net) do not reset the flag upon the last close.

By this I am resurrecting an old bug, see References. We are hitting
it regularly now, i.e. with updated util-linux, ergo login.

Here, I am changing a behavior introduced back in 2.1 times. It would
better have a long time testing before goes upstream.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Bryan Mason <bmason@redhat.com>
References: https://lkml.org/lkml/2009/11/11/223
References: https://bugzilla.redhat.com/show_bug.cgi?id=504703
References: https://bugzilla.novell.com/show_bug.cgi?id=797042
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15 22:49:36 -08:00
..
accessibility
acpi Merge branch 'acpi-assorted' 2013-01-04 23:10:29 +01:00
amba Drivers: amba: remove __dev* attributes. 2013-01-03 15:57:02 -08:00
ata Drivers: ata: remove __dev* attributes. 2013-01-03 15:57:03 -08:00
atm Drivers: atm: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
auxdisplay Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
base Merge branch 'pm-sleep' 2013-01-06 00:36:17 +01:00
bcma Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-01-08 07:31:49 -08:00
block Drivers: block: remove __dev* attributes. 2013-01-03 15:57:15 -08:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2012-12-12 18:07:07 -08:00
bus Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
cdrom Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
char TTY: synclink, remove unneeded tests 2013-01-15 22:43:15 -08:00
clk ARM: arm-soc fixes for 3.8-rc 2013-01-08 18:53:56 -08:00
clocksource Drivers: clocksource: remove __dev* attributes. 2013-01-03 15:57:15 -08:00
connector Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
cpufreq cpufreq / governor: Fix problem with cpufreq_ondemand or cpufreq_conservative 2013-01-03 13:11:19 +01:00
cpuidle cpuidle: fix lock contention in the idle path 2013-01-03 13:11:06 +01:00
crypto Drivers: crypto: remove __dev* attributes. 2013-01-03 15:57:02 -08:00
dca
devfreq Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
dio
dma ARM: arm-soc fixes for 3.8-rc 2013-01-08 18:53:56 -08:00
edac Two error path fixes causing a crash and a Kconfig fix for an issue 2013-01-09 08:43:56 -08:00
eisa
extcon
firewire Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-12-13 12:00:02 -08:00
firmware Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
gpio Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
gpu Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux 2013-01-08 16:08:10 -08:00
hid Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
hsi Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
hv
hwmon Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
hwspinlock
i2c i2c: remove __dev* attributes from subsystem 2012-12-22 20:13:45 +01:00
ide Drivers: ide: remove __dev* attributes. 2013-01-03 15:57:03 -08:00
idle intel_idle: pr_debug information need separated 2013-01-03 13:11:05 +01:00
iio Drivers: iio: remove __dev* attributes. 2013-01-03 15:57:03 -08:00
infiniband Drivers: infinband: remove __dev* attributes. 2013-01-03 15:57:15 -08:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2013-01-04 10:30:11 -08:00
iommu Drivers: iommu: remove __dev* attributes. 2013-01-03 15:57:14 -08:00
ipack TTY: switch tty_flip_buffer_push 2013-01-15 22:30:15 -08:00
irqchip ARM: arm-soc: Device-tree updates, take 2 2012-12-14 14:42:53 -08:00
isdn TTY: switch tty_flip_buffer_push 2013-01-15 22:30:15 -08:00
leds leds: leds-gpio: set devm_gpio_request_one() flags param correctly 2013-01-02 17:58:41 -08:00
lguest lguest: fix typo 2012-12-18 15:19:06 +10:30
macintosh Drivers: macintosh: remove __dev* attributes. 2013-01-03 15:57:14 -08:00
md Miscellaneous device-mapper fixes, cleanups and performance improvements. 2012-12-21 17:08:06 -08:00
media Drivers: media: remove __dev* attributes. 2013-01-03 15:57:02 -08:00
memory Drivers: memory: remove __dev* attributes. 2013-01-03 15:57:14 -08:00
memstick
message Drivers: message: remove __dev* attributes. 2013-01-03 15:57:14 -08:00
mfd Drivers: mfd: remove __dev* attributes. 2013-01-03 15:57:14 -08:00
misc Merge git://www.linux-watchdog.org/linux-watchdog 2012-12-21 17:10:29 -08:00
mmc TTY: switch tty_flip_buffer_push 2013-01-15 22:30:15 -08:00
mtd Drivers: mtd: remove __dev* attributes. 2013-01-03 15:57:03 -08:00
net TTY: switch tty_flip_buffer_push 2013-01-15 22:30:15 -08:00
nfc Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
nubus
of of: Fix export of of_find_matching_node_and_match() 2012-12-19 10:58:53 +00:00
oprofile
parisc Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
parport Drivers: parport: remove __dev* attributes. 2013-01-03 15:57:03 -08:00
pci PCI: Reduce Ricoh 0xe822 SD card reader base clock frequency to 50MHz 2012-12-26 10:43:06 -07:00
pcmcia ARM: arm-soc: Header cleanups 2012-12-12 11:45:16 -08:00
pinctrl ARM: arm-soc fixes for 3.8-rc 2013-01-08 18:53:56 -08:00
platform Drivers: platform: x86: remove __dev* attributes. 2013-01-03 15:57:03 -08:00
pnp PNP: Handle IORESOURCE_BITS in resource allocation 2013-01-03 13:10:53 +01:00
power ARM: arm-soc fixes for 3.8-rc 2013-01-08 18:53:56 -08:00
pps Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
ps3 Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
ptp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2012-12-12 18:07:07 -08:00
pwm pwm: Changes for v3.8-rc1 2012-12-19 08:19:07 -08:00
rapidio Driver core updates for 3.8-rc1 2012-12-11 13:13:55 -08:00
regulator Drivers: regulator: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
remoteproc Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
rpmsg Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
rtc drivers/rtc/rtc-vt8500.c: fix handling of data passed in struct rtc_time 2013-01-04 16:11:48 -08:00
s390 TTY: switch tty_schedule_flip 2013-01-15 22:43:15 -08:00
sbus Drivers: sbus: remove __dev* attributes. 2013-01-03 15:57:03 -08:00
scsi Drivers: scsi: remove __dev* attributes. 2013-01-03 15:57:01 -08:00
sfi
sh Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
sn Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
spi spi/sh-hspi: fix return value check in hspi_probe(). 2012-12-19 15:11:41 +00:00
ssb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-01-08 07:31:49 -08:00
staging TTY: switch tty_schedule_flip 2013-01-15 22:43:15 -08:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2012-12-15 14:25:10 -08:00
tc
thermal Drivers: thermal: remove __dev* attributes. 2013-01-03 15:57:02 -08:00
tty TTY: do not reset master's packet mode 2013-01-15 22:49:36 -08:00
uio ARM: arm-soc: SoC updates for 3.8 2012-12-12 12:05:15 -08:00
usb TTY: switch tty_flip_buffer_push 2013-01-15 22:30:15 -08:00
uwb
vfio vfio-pci: Enable device before attempting reset 2012-12-07 13:43:51 -07:00
vhost Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2012-12-15 14:25:10 -08:00
video ARM: arm-soc fixes for 3.8-rc 2013-01-08 18:53:56 -08:00
virt Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2012-12-18 09:58:09 -08:00
virtio Drivers: virtio: remove __dev* attributes. 2013-01-03 15:57:01 -08:00
vlynq Drivers: vlynq: remove __dev* attributes. 2013-01-03 15:57:01 -08:00
vme
w1 Drivers: w1: remove last __devexit_p() instance 2013-01-03 15:57:01 -08:00
watchdog watchdog: twl4030_wdt: add DT support 2013-01-02 12:07:05 +01:00
xen Drivers: xen: remove __dev* attributes. 2013-01-03 15:57:01 -08:00
zorro Drivers: zorro: remove CONFIG_HOTPLUG usage 2013-01-03 15:57:01 -08:00
Kconfig
Makefile