[lkml]   [2012]   [Feb]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH 1/1] TTY: fix PTY hangup vs close race
Commit d3bda5298 (TTY: get rid of BTM around devpts_*) moved
devpts_pty_kill out of BTM, but the BTM was not protecting only
devpts_pty_kill, but also tty->link. Hence move the function back at
this late stage until this gets resolved properly some time later.

I was confused by tty_vhangup(tty->link) outside BTM. But inside of
tty_vhangup, there is a check for tty == NULL. But we cannot add such
a check here. We have to have the tty and free the devpts node...

Signed-off-by: Jiri Slaby <>
Reported-by: Sasha Levin <>

Gee, I messed up Greg's address again...

drivers/tty/pty.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index fa1bd2e..95037aa 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -54,8 +54,9 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
if (tty->driver->subtype == PTY_TYPE_MASTER) {
set_bit(TTY_OTHER_CLOSED, &tty->flags);
- tty_unlock();
+ /* BTM protects tty->link here */
+ tty_unlock();

 \ /
  Last update: 2012-02-19 22:21    [W:0.075 / U:46.936 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site