3.6.11.9-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold [ Upstream commit d8a083cc746664916d9d36ed9e4d08a29525f245 ] Fix race in mos7840_get_reg which unconditionally manipulated the control urb (which may already be in use) by adding a control-urb busy flag. Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman Signed-off-by: Steven Rostedt --- drivers/usb/serial/mos7840.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c index 15cc47d..2e218ee 100644 --- a/drivers/usb/serial/mos7840.c +++ b/drivers/usb/serial/mos7840.c @@ -187,6 +187,10 @@ #define LED_ON_MS 500 #define LED_OFF_MS 500 +enum mos7840_flag { + MOS7840_FLAG_CTRL_BUSY, +}; + static int device_type; static const struct usb_device_id id_table[] = { @@ -247,6 +251,8 @@ struct moschip_port { bool led_flag; struct timer_list led_timer1; /* Timer for LED on */ struct timer_list led_timer2; /* Timer for LED off */ + + unsigned long flags; }; static bool debug; @@ -507,11 +513,11 @@ static void mos7840_control_callback(struct urb *urb) /* this urb is terminated, clean up */ dbg("%s - urb shutting down with status: %d", __func__, status); - return; + goto out; default: dbg("%s - nonzero urb status received: %d", __func__, status); - return; + goto out; } dbg("%s urb buffer size is %d", __func__, urb->actual_length); @@ -524,6 +530,8 @@ static void mos7840_control_callback(struct urb *urb) mos7840_handle_new_msr(mos7840_port, regval); else if (mos7840_port->MsrLsr == 1) mos7840_handle_new_lsr(mos7840_port, regval); +out: + clear_bit_unlock(MOS7840_FLAG_CTRL_BUSY, &mos7840_port->flags); } static int mos7840_get_reg(struct moschip_port *mcs, __u16 Wval, __u16 reg, @@ -534,6 +542,9 @@ static int mos7840_get_reg(struct moschip_port *mcs, __u16 Wval, __u16 reg, unsigned char *buffer = mcs->ctrl_buf; int ret; + if (test_and_set_bit_lock(MOS7840_FLAG_CTRL_BUSY, &mcs->flags)) + return -EBUSY; + dr->bRequestType = MCS_RD_RTYPE; dr->bRequest = MCS_RDREQ; dr->wValue = cpu_to_le16(Wval); /* 0 */ @@ -545,6 +556,9 @@ static int mos7840_get_reg(struct moschip_port *mcs, __u16 Wval, __u16 reg, mos7840_control_callback, mcs); mcs->control_urb->transfer_buffer_length = 2; ret = usb_submit_urb(mcs->control_urb, GFP_ATOMIC); + if (ret) + clear_bit_unlock(MOS7840_FLAG_CTRL_BUSY, &mcs->flags); + return ret; } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/