From 040b6362d58fe9a344e053546c12bf821f6fce99 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov <oleg@tv-sign.ru> Date: Fri, 1 Jun 2007 00:46:53 -0700 Subject: [PATCH] tty: fix leakage of -ERESTARTSYS to userland Spotted by Satoru Takeuchi. kill_pgrp(task_pgrp(current)) sends the signal to the current's thread group, but can choose any sub-thread as a target for signal_wake_up(). This means that job_control() and tty_check_change() may return -ERESTARTSYS without signal_pending(). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Cc: Roland McGrath <roland@redhat.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- drivers/char/n_tty.c | 1 + drivers/char/tty_io.c | 3 ++- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c index b3d4ccc33a47e..154f42203b056 100644 --- a/drivers/char/n_tty.c +++ b/drivers/char/n_tty.c @@ -1191,6 +1191,7 @@ static int job_control(struct tty_struct *tty, struct file *file) is_current_pgrp_orphaned()) return -EIO; kill_pgrp(task_pgrp(current), SIGTTIN, 1); + set_thread_flag(TIF_SIGPENDING); return -ERESTARTSYS; } } diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 75d2a46e106fe..3752edc30c366 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -1148,7 +1148,8 @@ int tty_check_change(struct tty_struct * tty) return 0; if (is_current_pgrp_orphaned()) return -EIO; - (void) kill_pgrp(task_pgrp(current), SIGTTOU, 1); + kill_pgrp(task_pgrp(current), SIGTTOU, 1); + set_thread_flag(TIF_SIGPENDING); return -ERESTARTSYS; } -- 2.39.5