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linux/drivers/tty
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Linus Torvalds 966031f340 n_tty: fix EXTPROC vs ICANON interaction with TIOCINQ (aka FIONREAD) 
We added support for EXTPROC back in 2010 in commit 26df6d1340 ("tty:
Add EXTPROC support for LINEMODE") and the intent was to allow it to
override some (all?) ICANON behavior.  Quoting from that original commit
message:

         There is a new bit in the termios local flag word, EXTPROC.
         When this bit is set, several aspects of the terminal driver
         are disabled.  Input line editing, character echo, and mapping
         of signals are all disabled.  This allows the telnetd to turn
         off these functions when in linemode, but still keep track of
         what state the user wants the terminal to be in.

but the problem turns out that "several aspects of the terminal driver
are disabled" is a bit ambiguous, and you can really confuse the n_tty
layer by setting EXTPROC and then causing some of the ICANON invariants
to no longer be maintained.

This fixes at least one such case (TIOCINQ) becoming unhappy because of
the confusion over whether ICANON really means ICANON when EXTPROC is set.

This basically makes TIOCINQ match the case of read: if EXTPROC is set,
we ignore ICANON.  Also, make sure to reset the ICANON state ie EXTPROC
changes, not just if ICANON changes.

Fixes: 26df6d1340 ("tty: Add EXTPROC support for LINEMODE")
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Reported-by: syzkaller <syzkaller@googlegroups.com>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-21 11:19:22 +01:00
..
hvc TTY/Serial patches for 4.15-rc1 2017-11-13 21:05:31 -08:00
ipwireless treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
serdev serdev: ttyport: fix tty locking in close 2017-11-28 16:00:50 +01:00
serial serial: 8250_early: Only set divisor if valid clk & baud 2017-11-28 15:55:15 +01:00
vt treewide: Switch DEFINE_TIMER callbacks to struct timer_list * 2017-11-21 15:57:05 -08:00
amiserial.c
bfin_jtag_comm.c
cyclades.c treewide: Switch DEFINE_TIMER callbacks to struct timer_list * 2017-11-21 15:57:05 -08:00
ehv_bytechan.c
goldfish.c
isicom.c treewide: Switch DEFINE_TIMER callbacks to struct timer_list * 2017-11-21 15:57:05 -08:00
Kconfig
Makefile
metag_da.c
mips_ejtag_fdc.c
moxa.c treewide: Switch DEFINE_TIMER callbacks to struct timer_list * 2017-11-21 15:57:05 -08:00
moxa.h
mxser.c
mxser.h
n_gsm.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
n_hdlc.c
n_null.c
n_r3964.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
n_tracerouter.c
n_tracesink.c
n_tracesink.h
n_tty.c n_tty: fix EXTPROC vs ICANON interaction with TIOCINQ (aka FIONREAD) 2017-12-21 11:19:22 +01:00
nozomi.c
pty.c
rocket_int.h
rocket.c treewide: Switch DEFINE_TIMER callbacks to struct timer_list * 2017-11-21 15:57:05 -08:00
rocket.h
synclink_gt.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
synclink.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
synclinkmp.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
sysrq.c TTY/Serial patches for 4.15-rc1 2017-11-13 21:05:31 -08:00
tty_audit.c
tty_baudrate.c
tty_buffer.c
tty_io.c
tty_ioctl.c
tty_jobctrl.c
tty_ldisc.c TTY/Serial patches for 4.15-rc1 2017-11-13 21:05:31 -08:00
tty_ldsem.c
tty_mutex.c
tty_port.c
vcc.c