linux-stable.git/drivers/tty, branch v3.18.136

serial: fsl_lpuart: clear parity enable bit when disable parity

2019-02-20T09:08:56+00:00

[ Upstream commit 397bd9211fe014b347ca8f95a8f4e1017bac1aeb ]

Current driver only enable parity enable bit and never clear it
when user set the termios. The fix clear the parity enable bit when
PARENB flag is not set in termios->c_cflag.

Cc: Lukas Wunner 
Signed-off-by: Andy Duan 
Reviewed-by: Fabio Estevam 
Acked-by: Uwe Kleine-König 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

vt: invoke notifier on screen size change

2019-02-06T16:34:52+00:00

commit 0c9b1965faddad7534b6974b5b36c4ad37998f8e upstream.

User space using poll() on /dev/vcs devices are not awaken when a
screen size change occurs. Let's fix that.

Signed-off-by: Nicolas Pitre 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

tty/n_hdlc: fix __might_sleep warning

2019-02-06T16:34:51+00:00

commit fc01d8c61ce02c034e67378cd3e645734bc18c8c upstream.

Fix __might_sleep warning[1] in tty/n_hdlc.c read due to copy_to_user
call while current is TASK_INTERRUPTIBLE.  This is a false positive
since the code path does not depend on current state remaining
TASK_INTERRUPTIBLE.  The loop breaks out and sets TASK_RUNNING after
calling copy_to_user.

This patch supresses the warning by setting TASK_RUNNING before calling
copy_to_user.

[1] https://syzkaller.appspot.com/bug?id=17d5de7f1fcab794cb8c40032f893f52de899324

Signed-off-by: Paul Fulghum 
Reported-by: syzbot 
Cc: Tetsuo Handa 
Cc: Alan Cox 
Cc: stable 
Acked-by: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

tty: Handle problem if line discipline does not have receive_buf

2019-02-06T16:34:51+00:00

commit 27cfb3a53be46a54ec5e0bd04e51995b74c90343 upstream.

Some tty line disciplines do not have a receive buf callback, so
properly check for that before calling it.  If they do not have this
callback, just eat the character quietly, as we can't fail this call.

Reported-by: Jann Horn 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

tty/ldsem: Wake up readers after timed out down_write()

2019-01-26T08:44:24+00:00

commit 231f8fd0cca078bd4396dd7e380db813ac5736e2 upstream.

ldsem_down_read() will sleep if there is pending writer in the queue.
If the writer times out, readers in the queue should be woken up,
otherwise they may miss a chance to acquire the semaphore until the last
active reader will do ldsem_up_read().

There was a couple of reports where there was one active reader and
other readers soft locked up:
  Showing all locks held in the system:
  2 locks held by khungtaskd/17:
   #0:  (rcu_read_lock){......}, at: watchdog+0x124/0x6d1
   #1:  (tasklist_lock){.+.+..}, at: debug_show_all_locks+0x72/0x2d3
  2 locks held by askfirst/123:
   #0:  (&tty->ldisc_sem){.+.+.+}, at: ldsem_down_read+0x46/0x58
   #1:  (&ldata->atomic_read_lock){+.+...}, at: n_tty_read+0x115/0xbe4

Prevent readers wait for active readers to release ldisc semaphore.

Link: lkml.kernel.org/r/20171121132855.ajdv4k6swzhvktl6@wfg-t540p.sh.intel.com
Link: lkml.kernel.org/r/20180907045041.GF1110@shao2-debian
Cc: Jiri Slaby 
Cc: Peter Zijlstra 
Cc: stable@vger.kernel.org
Reported-by: kernel test robot 
Signed-off-by: Dmitry Safonov 
Signed-off-by: Greg Kroah-Hartman

drivers/tty: add missing of_node_put()

2018-12-21T13:08:48+00:00

[ Upstream commit dac097c4546e4c5b16dd303a1e97c1d319c8ab3e ]

of_find_node_by_path() acquires a reference to the node
returned by it and that reference needs to be dropped by its caller.
This place is not doing this, so fix it.

Signed-off-by: Yangtao Li 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

kgdboc: fix KASAN global-out-of-bounds bug in param_set_kgdboc_var()

2018-12-13T08:22:32+00:00

commit dada6a43b0402eba438a17ac86fdc64ac56a4607 upstream.

This patch is trying to fix KE issue due to
"BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198"
reported by Syzkaller scan."

[26364:syz-executor0][name:report8t]BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198
[26364:syz-executor0][name:report&]Read of size 1 at addr ffffff900e44f95f by task syz-executor0/26364
[26364:syz-executor0][name:report&]
[26364:syz-executor0]CPU: 7 PID: 26364 Comm: syz-executor0 Tainted: G W 0
[26364:syz-executor0]Call trace:
[26364:syz-executor0][] dump_bacIctrace+Ox0/0x470
[26364:syz-executor0][] show_stack+0x20/0x30
[26364:syz-executor0][] dump_stack+Oxd8/0x128
[26364:syz-executor0][] print_address_description +0x80/0x4a8
[26364:syz-executor0][] kasan_report+Ox178/0x390
[26364:syz-executor0][] _asan_report_loadi_noabort+Ox18/0x20
[26364:syz-executor0][] param_set_kgdboc_var+Ox194/0x198
[26364:syz-executor0][] param_attr_store+Ox14c/0x270
[26364:syz-executor0][] module_attr_store+0x60/0x90
[26364:syz-executor0][] sysfs_kl_write+Ox100/0x158
[26364:syz-executor0][] kernfs_fop_write+0x27c/0x3a8
[26364:syz-executor0][] do_loop_readv_writev+0x114/0x1b0
[26364:syz-executor0][] do_readv_writev+0x4f8/0x5e0
[26364:syz-executor0][] vfs_writev+0x7c/Oxb8
[26364:syz-executor0][] SyS_writev+Oxcc/0x208
[26364:syz-executor0][] elO_svc_naked +0x24/0x28
[26364:syz-executor0][name:report&]
[26364:syz-executor0][name:report&]The buggy address belongs to the variable:
[26364:syz-executor0][name:report&] kgdb_tty_line+Ox3f/0x40
[26364:syz-executor0][name:report&]
[26364:syz-executor0][name:report&]Memory state around the buggy address:
[26364:syz-executor0] ffffff900e44f800: 00 00 00 00 00 04 fa fa fa fa fa fa 00 fa fa fa
[26364:syz-executor0] ffffff900e44f880: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa
[26364:syz-executor0]> ffffff900e44f900: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00
[26364:syz-executor0][name:report&]                                       ^
[26364:syz-executor0] ffffff900e44f980: 00 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa
[26364:syz-executor0] ffffff900e44fa00: 04 fa fa fa fa fa fa fa 00 fa fa fa fa fa fa fa
[26364:syz-executor0][name:report&]
[26364:syz-executor0][name:panic&]Disabling lock debugging due to kernel taint
[26364:syz-executor0]------------[cut here]------------

After checking the source code, we've found there might be an out-of-bounds
access to "config[len - 1]" array when the variable "len" is zero.

Signed-off-by: Macpaul Lin 
Acked-by: Daniel Thompson 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

kgdboc: Fix warning with module build

2018-12-13T08:22:30+00:00

commit 1cd25cbb2fedbc777f3a8c3cb1ba69b645aeaa64 upstream.

After 2dd453168643 ("kgdboc: Fix restrict error"), kgdboc_option_setup is
now only used when built in, resulting in a warning when compiled as a
module:

drivers/tty/serial/kgdboc.c:134:12: warning: 'kgdboc_option_setup' defined but not used [-Wunused-function]
 static int kgdboc_option_setup(char *opt)
            ^~~~~~~~~~~~~~~~~~~

Move the function under the appropriate ifdef for builtin only.

Fixes: 2dd453168643 ("kgdboc: Fix restrict error")
Reported-by: Stephen Rothwell 
Signed-off-by: Laura Abbott 
Signed-off-by: Greg Kroah-Hartman

kgdboc: Fix restrict error

2018-12-13T08:22:30+00:00

commit 2dd453168643d9475028cd867c57e65956a0f7f9 upstream.

There's an error when compiled with restrict:

drivers/tty/serial/kgdboc.c: In function ‘configure_kgdboc’:
drivers/tty/serial/kgdboc.c:137:2: error: ‘strcpy’ source argument is the same
as destination [-Werror=restrict]
  strcpy(config, opt);
  ^~~~~~~~~~~~~~~~~~~

As the error implies, this is from trying to use config as both source and
destination. Drop the call to the function where config is the argument
since nothing else happens in the function.

Signed-off-by: Laura Abbott 
Reviewed-by: Daniel Thompson 
Signed-off-by: Greg Kroah-Hartman

tty: wipe buffer if not echoing data

2018-12-01T08:48:05+00:00

commit b97b3d9fb57860a60592859e332de7759fd54c2e upstream.

If we are not echoing the data to userspace or the console is in icanon
mode, then perhaps it is a "secret" so we should wipe it once we are
done with it.

This mirrors the logic that the audit code has.

Reported-by: aszlig 
Tested-by: Milan Broz 
Tested-by: Daniel Zatovic 
Tested-by: aszlig 
Cc: Willy Tarreau 
Signed-off-by: Greg Kroah-Hartman