From 46154d295b82ff4f470dd3934440433ce333825b Mon Sep 17 00:00:00 2001 From: Jia-Ju Bai Date: Tue, 8 Jan 2019 21:04:48 +0800 Subject: isdn: i4l: isdn_tty: Fix some concurrency double-free bugs [ Upstream commit 2ff33d6637393fe9348357285931811b76e1402f ] The functions isdn_tty_tiocmset() and isdn_tty_set_termios() may be concurrently executed. isdn_tty_tiocmset isdn_tty_modem_hup line 719: kfree(info->dtmf_state); line 721: kfree(info->silence_state); line 723: kfree(info->adpcms); line 725: kfree(info->adpcmr); isdn_tty_set_termios isdn_tty_modem_hup line 719: kfree(info->dtmf_state); line 721: kfree(info->silence_state); line 723: kfree(info->adpcms); line 725: kfree(info->adpcmr); Thus, some concurrency double-free bugs may occur. These possible bugs are found by a static tool written by myself and my manual code review. To fix these possible bugs, the mutex lock "modem_info_mutex" used in isdn_tty_tiocmset() is added in isdn_tty_set_termios(). Signed-off-by: Jia-Ju Bai Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/isdn/i4l/isdn_tty.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/isdn/i4l/isdn_tty.c') diff --git a/drivers/isdn/i4l/isdn_tty.c b/drivers/isdn/i4l/isdn_tty.c index 63eaa0a9f8a1..d4e0d1602c80 100644 --- a/drivers/isdn/i4l/isdn_tty.c +++ b/drivers/isdn/i4l/isdn_tty.c @@ -1455,15 +1455,19 @@ isdn_tty_set_termios(struct tty_struct *tty, struct ktermios *old_termios) { modem_info *info = (modem_info *) tty->driver_data; + mutex_lock(&modem_info_mutex); if (!old_termios) isdn_tty_change_speed(info); else { if (tty->termios.c_cflag == old_termios->c_cflag && tty->termios.c_ispeed == old_termios->c_ispeed && - tty->termios.c_ospeed == old_termios->c_ospeed) + tty->termios.c_ospeed == old_termios->c_ospeed) { + mutex_unlock(&modem_info_mutex); return; + } isdn_tty_change_speed(info); } + mutex_unlock(&modem_info_mutex); } /* -- cgit v1.2.3 From 47b002658f6cefb3db465910add7069b696935a0 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 7 Mar 2019 18:06:23 +0100 Subject: isdn: isdn_tty: fix build warning of strncpy Not upstream as isdn is long deleted. Fix up a strncpy build warning for isdn_tty_suspend() using strscpy. It's not like anyone uses this code anyway, and this gets rid of a build warnings so that we can see real warnings as they pop up over time. Signed-off-by: Greg Kroah-Hartman --- drivers/isdn/i4l/isdn_tty.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/isdn/i4l/isdn_tty.c') diff --git a/drivers/isdn/i4l/isdn_tty.c b/drivers/isdn/i4l/isdn_tty.c index d4e0d1602c80..6b7eed722e43 100644 --- a/drivers/isdn/i4l/isdn_tty.c +++ b/drivers/isdn/i4l/isdn_tty.c @@ -786,7 +786,7 @@ isdn_tty_suspend(char *id, modem_info *info, atemu *m) cmd.parm.cmsg.para[3] = 4; /* 16 bit 0x0004 Suspend */ cmd.parm.cmsg.para[4] = 0; cmd.parm.cmsg.para[5] = l; - strncpy(&cmd.parm.cmsg.para[6], id, l); + strscpy(&cmd.parm.cmsg.para[6], id, l); cmd.command = CAPI_PUT_MESSAGE; cmd.driver = info->isdn_driver; cmd.arg = info->isdn_channel; -- cgit v1.2.3