lkml.org 
[lkml]   [2018]   [Aug]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] serial: mxs-auart: Fix potential infinite loop
Date
On the error path of mxs_auart_request_gpio_irq() is performed
backward iterating with index i of enum type. Underline enum type
may be unsigned char. In this case check (--i >= 0) will be always
true and error handling goes into infinite loop.

The patch changes type of index variable to int.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Anton Vasilyev <vasilyev@ispras.ru>
---
drivers/tty/serial/mxs-auart.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index 76aa289652f7..89b34bb09cde 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -1617,7 +1617,7 @@ static void mxs_auart_free_gpio_irq(struct mxs_auart_port *s)
static int mxs_auart_request_gpio_irq(struct mxs_auart_port *s)
{
int *irq = s->gpio_irq;
- enum mctrl_gpio_idx i;
+ int i;
int err = 0;

for (i = 0; (i < UART_GPIO_MAX) && !err; i++) {
@@ -1634,8 +1634,9 @@ static int mxs_auart_request_gpio_irq(struct mxs_auart_port *s)

/*
* If something went wrong, rollback.
+ * Be careful: i may be unsigned.
*/
- while (err && (--i >= 0))
+ while (err && (i-- > 0))
if (irq[i] >= 0)
free_irq(irq[i], s);

--
2.18.0
\
 
 \ /
  Last update: 2018-08-06 18:44    [W:0.028 / U:0.872 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site