diff options
| author | Peter Hurley <peter@hurleysoftware.com> | 2013-11-19 08:46:27 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-12-04 11:05:41 -0800 |
| commit | a4839c4c246a66ec0bb40aaa78aeeca4fd38f252 (patch) | |
| tree | 596e947d2831f1a1338aeecca53ef30c7fb735ef /drivers/tty/tty_io.c | |
| parent | a5ce6dc48a0d0304c7f6588100cf89163a0cea56 (diff) | |
tty: Reset hupped state on open
commit d4855e1fc03c2bb32dd64badf51cec5a2a26ab2a upstream.
A common security idiom is to hangup the current tty (via vhangup())
after forking but before execing a root shell. This hangs up any
existing opens which other processes may have and ensures subsequent
opens have the necessary permissions to open the root shell tty/pty.
Reset the TTY_HUPPED state after the driver has successfully
returned the opened tty (perform the reset while the tty is locked
to avoid racing with concurrent hangups).
Reported-by: Heorhi Valakhanovich <valahanovich@tut.by>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-by: Heorhi Valakhanovich <valahanovich@tut.by>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/tty_io.c')
| -rw-r--r-- | drivers/tty/tty_io.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 3a1a01af9a8..c74a00ad7ad 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2086,6 +2086,7 @@ retry_open: filp->f_op = &tty_fops; goto retry_open; } + clear_bit(TTY_HUPPED, &tty->flags); tty_unlock(tty); |