From: Peter Hurley <[email protected]>
3.4.108-rc1 review patch. If anyone has any objections, please let me know.
------------------
commit 37480a05685ed5b8e1b9bf5e5c53b5810258b149 upstream.
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 <[email protected]>
Cc: Howard Chu <[email protected]>
Cc: One Thousand Gnomes <[email protected]>
Cc: Jiri Slaby <[email protected]>
Signed-off-by: Peter Hurley <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Zefan Li <[email protected]>
---
drivers/tty/pty.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index cf9a191..bc955d7 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -173,6 +173,9 @@ static int pty_signal(struct tty_struct *tty, int sig)
unsigned long flags;
struct pid *pgrp;
+ if (sig != SIGINT && sig != SIGQUIT && sig != SIGTSTP)
+ return -EINVAL;
+
if (tty->link) {
spin_lock_irqsave(&tty->link->ctrl_lock, flags);
pgrp = get_pid(tty->link->pgrp);
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
