wait_event_interruptible_timeout returns a long The return was being assigned to an int causing an integer overflow when the remaining jiffies > INT_MAX resulting in random error returns.
Use a long return value and convert to int ioctl return only on error.
When the return value of wait_event_interruptible_timeout was <= INT_MAX the number of remaining jiffies was returned which has no meaning for the user. Return 0 on success.
Reported-by: Michael Katzmann vk2bea@gmail.com Fixes: dbf3e7f654c0 ("Implement an ioctl to support the USMTMC-USB488 READ_STATUS_BYTE operation.") Cc: stable@vger.kernel.org Signed-off-by: Dave Penkler dpenkler@gmail.com --- Change V1 -> V2 Correct commit message wrongly stating the return value on success was from usb_control_msg
Change V2 -> V3 Add cc to stable line
drivers/usb/class/usbtmc.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c index 34e46ef308ab..e24277fef54a 100644 --- a/drivers/usb/class/usbtmc.c +++ b/drivers/usb/class/usbtmc.c @@ -482,6 +482,7 @@ static int usbtmc_get_stb(struct usbtmc_file_data *file_data, __u8 *stb) u8 *buffer; u8 tag; int rv; + long wait_rv;
dev_dbg(dev, "Enter ioctl_read_stb iin_ep_present: %d\n", data->iin_ep_present); @@ -511,16 +512,17 @@ static int usbtmc_get_stb(struct usbtmc_file_data *file_data, __u8 *stb) }
if (data->iin_ep_present) { - rv = wait_event_interruptible_timeout( + wait_rv = wait_event_interruptible_timeout( data->waitq, atomic_read(&data->iin_data_valid) != 0, file_data->timeout); - if (rv < 0) { - dev_dbg(dev, "wait interrupted %d\n", rv); + if (wait_rv < 0) { + dev_dbg(dev, "wait interrupted %ld\n", wait_rv); + rv = wait_rv; goto exit; }
- if (rv == 0) { + if (wait_rv == 0) { dev_dbg(dev, "wait timed out\n"); rv = -ETIMEDOUT; goto exit; @@ -539,6 +541,8 @@ static int usbtmc_get_stb(struct usbtmc_file_data *file_data, __u8 *stb)
dev_dbg(dev, "stb:0x%02x received %d\n", (unsigned int)*stb, rv);
+ rv = 0; + exit: /* bump interrupt bTag */ data->iin_bTag += 1;