| Message ID | 880aeea52f3bdde5e3e8843bbedb7fd068a58be2.1698565938.git.christophe.jaillet@wanadoo.fr (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | firmware: ti_sci: Fix an off-by-one in ti_sci_debugfs_create() | expand |
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 >
On Mon, Oct 30, 2023 at 11:00:59AM +0300, Dan Carpenter wrote: > 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. Ah sorry. It's an off by one. Yeah, that's a bug even if it doesn't affect runtime. I don't know why I didn't read this commit message better... regards, dan carpenter
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)); + info->d = debugfs_create_file(debug_name, 0444, NULL, info, + &ti_sci_debug_fops); if (IS_ERR(info->d)) return PTR_ERR(info->d);
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") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> --- drivers/firmware/ti_sci.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)