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| author | Greg Kroah-Hartman <gregkh@suse.de> | 2009-12-17 07:07:19 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-04-01 15:55:36 -0700 |
| commit | 4bbb96c37a538469960a95333a4f1bf74efedc94 (patch) | |
| tree | 99c4e073c34e7f521361cff6321f2aca7354a464 /drivers | |
| parent | c17975de81fa9937c2b5827ead464f044b30f9c2 (diff) | |
| download | lwn-4bbb96c37a538469960a95333a4f1bf74efedc94.tar.gz lwn-4bbb96c37a538469960a95333a4f1bf74efedc94.zip | |
tty: fix race in tty_fasync
commit 703625118069f9f8960d356676662d3db5a9d116 upstream.
We need to keep the lock held over the call to __f_setown() to
prevent a PID race.
Thanks to Al Viro for pointing out the problem, and to Travis for
making us look here in the first place.
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tavis Ormandy <taviso@google.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Julien Tinnes <jln@google.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/char/tty_io.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 9fc95178a7a9..c695ce7985e0 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -1912,8 +1912,8 @@ static int tty_fasync(int fd, struct file *filp, int on) pid = task_pid(current); type = PIDTYPE_PID; } - spin_unlock_irqrestore(&tty->ctrl_lock, flags); retval = __f_setown(filp, pid, type, 0); + spin_unlock_irqrestore(&tty->ctrl_lock, flags); if (retval) goto out; } else { |