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From: Jiri Slaby <jirislaby@gmail.com>
To: "Oyvind Aabling" <Oyvind.Aabling@uni-c.dk>
Cc: <linux-kernel@vger.kernel.org>, Jiri Slaby <jirislaby@gmail.com>
Subject: [RFT 9/9] Char: moxa, fix ioctl race
Date: Thu,  7 Feb 2008 20:11:25 +0100	[thread overview]
Message-ID: <1202411485-16022-9-git-send-email-jirislaby@gmail.com> (raw)
In-Reply-To: <1202411485-16022-1-git-send-email-jirislaby@gmail.com>

The lock fixes window between board->ready test and its port access.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
---
 drivers/char/moxa.c |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c
index fd9c946..6e170a4 100644
--- a/drivers/char/moxa.c
+++ b/drivers/char/moxa.c
@@ -299,6 +299,7 @@ static int moxa_ioctl(struct tty_struct *tty, struct file *file,
 		struct moxa_port *p;
 		unsigned int i, j;
 
+		mutex_lock(&moxa_openlock);
 		for (i = 0; i < MAX_BOARDS; i++) {
 			p = moxa_boards[i].ports;
 			for (j = 0; j < MAX_PORTS_PER_BOARD; j++, p++, argm++) {
@@ -307,10 +308,13 @@ static int moxa_ioctl(struct tty_struct *tty, struct file *file,
 					tmp.inq = MoxaPortRxQueue(p);
 					tmp.outq = MoxaPortTxQueue(p);
 				}
-				if (copy_to_user(argm, &tmp, sizeof(tmp)))
+				if (copy_to_user(argm, &tmp, sizeof(tmp))) {
+					mutex_unlock(&moxa_openlock);
 					return -EFAULT;
+				}
 			}
 		}
+		mutex_unlock(&moxa_openlock);
 		return 0;
 	} case MOXA_GET_OQUEUE:
 		status = MoxaPortTxQueue(ch);
@@ -324,6 +328,7 @@ static int moxa_ioctl(struct tty_struct *tty, struct file *file,
 		struct moxa_port *p;
 		unsigned int i, j;
 
+		mutex_lock(&moxa_openlock);
 		for (i = 0; i < MAX_BOARDS; i++) {
 			p = moxa_boards[i].ports;
 			for (j = 0; j < MAX_PORTS_PER_BOARD; j++, p++, argm++) {
@@ -344,10 +349,13 @@ static int moxa_ioctl(struct tty_struct *tty, struct file *file,
 				else
 					tmp.cflag = p->tty->termios->c_cflag;
 copy:
-				if (copy_to_user(argm, &tmp, sizeof(tmp)))
+				if (copy_to_user(argm, &tmp, sizeof(tmp))) {
+					mutex_unlock(&moxa_openlock);
 					return -EFAULT;
+				}
 			}
 		}
+		mutex_unlock(&moxa_openlock);
 		return 0;
 	}
 	case TIOCGSERIAL:
-- 
1.5.3.8


      parent reply	other threads:[~2008-02-07 19:17 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-07 19:11 [RFT 1/9] Char: moxa, merge 2 poll functions Jiri Slaby
2008-02-07 19:11 ` [RFT 2/9] Char: moxa, cleanup rx/tx Jiri Slaby
2008-02-07 19:11 ` [RFT 3/9] Char: moxa, serialise timer Jiri Slaby
2008-02-07 19:11 ` [RFT 4/9] Char: moxa, rework open/close Jiri Slaby
2008-02-07 19:11 ` [RFT 5/9] Char: moxa, little cleanup Jiri Slaby
2008-02-07 19:11 ` [RFT 6/9] Char: moxa, remove useless tty functions Jiri Slaby
2008-02-07 19:11 ` [RFT 7/9] Char: moxa, introduce MOXA_IS_320 macro Jiri Slaby
2008-02-07 19:11 ` [RFT 8/9] Char: moxa, notify about board readiness Jiri Slaby
2008-02-07 19:11 ` Jiri Slaby [this message]

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