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| author | Peter Hurley <peter@hurleysoftware.com> | 2015-01-19 21:05:03 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-02-02 21:09:54 +0300 |
| commit | 37480a05685ed5b8e1b9bf5e5c53b5810258b149 (patch) | |
| tree | 9a754bf217c5609849d1a8a43bc28b52471b1bf6 | |
| parent | 19e3ae6b4f07a87822c1c9e7ed99d31860e701af (diff) | |
| download | linux-37480a05685ed5b8e1b9bf5e5c53b5810258b149.tar.xz | |
tty: Prevent untrappable signals from malicious program
Commit 26df6d13406d1a5 ("tty: Add EXTPROC support for LINEMODE")
allows a process which has opened a pty master to send _any_ signal
to the process group of the pty slave. Although potentially
exploitable by a malicious program running a setuid program on
a pty slave, it's unknown if this exploit currently exists.
Limit to signals actually used.
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Howard Chu <hyc@symas.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: <stable@vger.kernel.org> # 2.6.36+
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/pty.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index a9d256d6e909..6e1f1505f04e 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -210,6 +210,9 @@ static int pty_signal(struct tty_struct *tty, int sig) { struct pid *pgrp; + if (sig != SIGINT && sig != SIGQUIT && sig != SIGTSTP) + return -EINVAL; + if (tty->link) { pgrp = tty_get_pgrp(tty->link); if (pgrp) |