| Message ID | ZXmwIwHe35wGfgzu@suswa |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] usb: fotg210-hcd: delete an incorrect bounds test | expand |
diff --git a/drivers/usb/fotg210/fotg210-hcd.c b/drivers/usb/fotg210/fotg210-hcd.c index b2f8b53cc8ef..8c5aaf860635 100644 --- a/drivers/usb/fotg210/fotg210-hcd.c +++ b/drivers/usb/fotg210/fotg210-hcd.c @@ -426,8 +426,6 @@ static void qh_lines(struct fotg210_hcd *fotg210, struct fotg210_qh *qh, td->urb); size -= temp; next += temp; - if (temp == size) - goto done; } temp = scnprintf(next, size, "\n"); @@ -435,7 +433,6 @@ static void qh_lines(struct fotg210_hcd *fotg210, struct fotg210_qh *qh, size -= temp; next += temp; -done: *sizep = size; *nextp = next; }
Here "temp" is the number of characters that we have written and "size" is the size of the buffer. The intent was clearly to say that if we have written to the end of the buffer then stop. However, for that to work the comparison should have been done on the original "size" value instead of the "size -= temp" value. Not only will that not trigger when we want to, but there is a small chance that it will trigger incorrectly before we want it to and we break from the loop slightly earlier than intended. This code was recently changed from using snprintf() to scnprintf(). With snprintf() we likely would have continued looping and passed a negative size parameter to snprintf(). This would have triggered an annoying WARN(). Now that we have converted to scnprintf() "size" will never drop below 1 and there is no real need for this test. We could change the condition to "if (temp <= 1) goto done;" but just deleting the test is cleanest. Fixes: 7d50195f6c50 ("usb: host: Faraday fotg210-hcd driver") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Lee Jones <lee@kernel.org> --- v2: Use the correct Fixes tag. Add Reviewed-by tags. drivers/usb/fotg210/fotg210-hcd.c | 3 --- 1 file changed, 3 deletions(-)