diff options
| author | Lee Jones <lee@kernel.org> | 2023-11-30 10:54:37 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-12-04 22:25:17 +0900 |
| commit | 7d7f794482b74e39d8c0cd830333eb40fc0234d4 (patch) | |
| tree | c213aed1a83100e38baacc6566e5159354d6f293 /drivers/usb/fotg210 | |
| parent | b385ef088c7aab20a2c0dc20d390d69a6620f0f3 (diff) | |
usb: fotg210-hcd: Replace snprintf() with the safer scnprintf() variant
There is a general misunderstanding amongst engineers that {v}snprintf()
returns the length of the data *actually* encoded into the destination
array. However, as per the C99 standard {v}snprintf() really returns
the length of the data that *would have been* written if there were
enough space for it. This misunderstanding has led to buffer-overruns
in the past. It's generally considered safer to use the {v}scnprintf()
variants in their place (or even sprintf() in simple cases). So let's
do that.
The uses in this file both seem to assume that data *has been* written!
Link: https://lwn.net/Articles/69419/
Link: https://github.com/KSPP/linux/issues/105
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Yuan-Hsin Chen <yhchen@faraday-tech.com>
Cc: Feng-Hsin Chiang <john453@faraday-tech.com>
Cc: Po-Yu Chuang <ratbert.chuang@gmail.com>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20231130105459.3208986-4-lee@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/fotg210')
| -rw-r--r-- | drivers/usb/fotg210/fotg210-hcd.c | 12 |
1 files changed, 4 insertions, 8 deletions
diff --git a/drivers/usb/fotg210/fotg210-hcd.c b/drivers/usb/fotg210/fotg210-hcd.c index 929106c16b29..b2f8b53cc8ef 100644 --- a/drivers/usb/fotg210/fotg210-hcd.c +++ b/drivers/usb/fotg210/fotg210-hcd.c @@ -404,9 +404,9 @@ static void qh_lines(struct fotg210_hcd *fotg210, struct fotg210_qh *qh, else if (td->hw_alt_next != list_end) mark = '/'; } - temp = snprintf(next, size, - "\n\t%p%c%s len=%d %08x urb %p", - td, mark, ({ char *tmp; + temp = scnprintf(next, size, + "\n\t%p%c%s len=%d %08x urb %p", + td, mark, ({ char *tmp; switch ((scratch>>8)&0x03) { case 0: tmp = "out"; @@ -424,17 +424,13 @@ static void qh_lines(struct fotg210_hcd *fotg210, struct fotg210_qh *qh, (scratch >> 16) & 0x7fff, scratch, td->urb); - if (size < temp) - temp = size; size -= temp; next += temp; if (temp == size) goto done; } - temp = snprintf(next, size, "\n"); - if (size < temp) - temp = size; + temp = scnprintf(next, size, "\n"); size -= temp; next += temp; |