4.19-stable review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter dan.carpenter@linaro.org
[ Upstream commit 7fbcd195e2b8cc952e4aeaeb50867b798040314c ]
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") Cc: stable stable@kernel.org Signed-off-by: Dan Carpenter dan.carpenter@linaro.org Reviewed-by: Linus Walleij linus.walleij@linaro.org Reviewed-by: Lee Jones lee@kernel.org Link: https://lore.kernel.org/r/ZXmwIwHe35wGfgzu@suswa Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/host/fotg210-hcd.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/drivers/usb/host/fotg210-hcd.c b/drivers/usb/host/fotg210-hcd.c index 1577424319613..d87b4fb0d9af6 100644 --- a/drivers/usb/host/fotg210-hcd.c +++ b/drivers/usb/host/fotg210-hcd.c @@ -426,8 +426,6 @@ static void qh_lines(struct fotg210_hcd *fotg210, struct fotg210_qh *qh, temp = size; size -= temp; next += temp; - if (temp == size) - goto done; }
temp = snprintf(next, size, "\n"); @@ -437,7 +435,6 @@ static void qh_lines(struct fotg210_hcd *fotg210, struct fotg210_qh *qh, size -= temp; next += temp;
-done: *sizep = size; *nextp = next; }