| Message ID | 1389941251-32692-2-git-send-email-wens@csie.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
From: Chen-Yu Tsai > snprintf should be passed the complete size of the buffer, including > the space for '\0'. The previous code resulted in the *_reset and > *_shutdown strings being truncated. ... > diff --git a/net/rfkill/rfkill-gpio.c b/net/rfkill/rfkill-gpio.c ... > - snprintf(rfkill->reset_name, len + 6 , "%s_reset", rfkill->name); > - snprintf(rfkill->shutdown_name, len + 9, "%s_shutdown", rfkill->name); > + snprintf(rfkill->reset_name, len + 7 , "%s_reset", rfkill->name); > + snprintf(rfkill->shutdown_name, len + 10, "%s_shutdown", rfkill->name); I can't find the context for the above, but they look very dubious. I'd expect: snprintf(foo, sizeof foo, ...). If you are trying to truncate rfkill->name you need to use %.*s. David
On Fri, Jan 17, 2014 at 5:46 PM, David Laight <David.Laight@aculab.com> wrote: > From: Chen-Yu Tsai >> snprintf should be passed the complete size of the buffer, including >> the space for '\0'. The previous code resulted in the *_reset and >> *_shutdown strings being truncated. > ... >> diff --git a/net/rfkill/rfkill-gpio.c b/net/rfkill/rfkill-gpio.c > ... >> - snprintf(rfkill->reset_name, len + 6 , "%s_reset", rfkill->name); >> - snprintf(rfkill->shutdown_name, len + 9, "%s_shutdown", rfkill->name); >> + snprintf(rfkill->reset_name, len + 7 , "%s_reset", rfkill->name); >> + snprintf(rfkill->shutdown_name, len + 10, "%s_shutdown", rfkill->name); > > I can't find the context for the above, but they look very dubious. > I'd expect: snprintf(foo, sizeof foo, ...). > If you are trying to truncate rfkill->name you need to use %.*s. The driver allocates these buffers on the fly, a few lines above: len = strlen(rfkill->name); rfkill->reset_name = devm_kzalloc(&pdev->dev, len + 7, GFP_KERNEL); rfkill->shutdown_name = devm_kzalloc(&pdev->dev, len + 10, GFP_KERNEL); I am not trying to truncate rfkill->name. Rather, the buffer length passed to snprintf was wrong, so the resulting name was truncated by one character. Thanks, ChenYu
diff --git a/net/rfkill/rfkill-gpio.c b/net/rfkill/rfkill-gpio.c index bd2a5b9..97ec12a 100644 --- a/net/rfkill/rfkill-gpio.c +++ b/net/rfkill/rfkill-gpio.c @@ -117,8 +117,8 @@ static int rfkill_gpio_probe(struct platform_device *pdev) if (!rfkill->shutdown_name) return -ENOMEM; - snprintf(rfkill->reset_name, len + 6 , "%s_reset", rfkill->name); - snprintf(rfkill->shutdown_name, len + 9, "%s_shutdown", rfkill->name); + snprintf(rfkill->reset_name, len + 7 , "%s_reset", rfkill->name); + snprintf(rfkill->shutdown_name, len + 10, "%s_shutdown", rfkill->name); rfkill->clk = devm_clk_get(&pdev->dev, clk_name);
snprintf should be passed the complete size of the buffer, including the space for '\0'. The previous code resulted in the *_reset and *_shutdown strings being truncated. Signed-off-by: Chen-Yu Tsai <wens@csie.org> --- net/rfkill/rfkill-gpio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)