Messages in this thread | | | Date | Mon, 30 Oct 2023 11:00:59 +0300 | From | Dan Carpenter <> | Subject | Re: [PATCH] firmware: ti_sci: Fix an off-by-one in ti_sci_debugfs_create() |
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On Sun, Oct 29, 2023 at 08:52:36AM +0100, Christophe JAILLET wrote: > The ending NULL is not taken into account by strncat(), so switch to > strlcat() to correctly compute the size of the available memory when > building 'debug_name'. > > Because of the difference in the return type between strncat() and > strlcat(), some code shuffling is needed. > > Fixes: aa276781a64a ("firmware: Add basic support for TI System Control Interface (TI-SCI) protocol")
The fixes tag isn't really required.
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> > --- > drivers/firmware/ti_sci.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c > index 7041befc756a..1036c6b0f3eb 100644 > --- a/drivers/firmware/ti_sci.c > +++ b/drivers/firmware/ti_sci.c > @@ -181,10 +181,9 @@ static int ti_sci_debugfs_create(struct platform_device *pdev, > /* Setup NULL termination */ > info->debug_buffer[info->debug_region_size] = 0; > > - info->d = debugfs_create_file(strncat(debug_name, dev_name(dev), > - sizeof(debug_name) - > - sizeof("ti_sci_debug@")), > - 0444, NULL, info, &ti_sci_debug_fops); > + strlcat(debug_name, dev_name(dev), sizeof(debug_name));
Eventually we are going to want to get rid for the strlcat() as well, right? Everyone hates strl* functions because they do a strlen() on the src string. It's fine if the src string is a string constant, I suppose. Here we basically trust dev_name() to be reasonable so either strncat and strlcpy() are fine I guess...
But it's is more readable if the we use snprintf().
snprintf(debug_name, sizeof(debug_name), "ti_sci_debug@%s", dev_name(dev));
regards, dan carpenter
> + info->d = debugfs_create_file(debug_name, 0444, NULL, info, > + &ti_sci_debug_fops); > if (IS_ERR(info->d)) > return PTR_ERR(info->d); > > -- > 2.34.1 >
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