[PATCH] media: siano: Replace strlcat() with snprintf() in sms_ir_init()

[PATCH] media: siano: Replace strlcat() with snprintf() in sms_ir_init()

[Mariia Nikitash]

In preparation for removing the deprecated strlcat() API[1],
replace the strscpy() and strlcat() calls with a single snprintf()
call to construct the IR device path.

Both the source and destination buffers have the same capacity,
and the return values are unused. This preserves the resulting
string, including truncation behavior.

Link: https://github.com/KSPP/linux/issues/370 [1]
Signed-off-by: Mariia Nikitash <nikitash.mariiaw@gmail.com>
---
 drivers/media/common/siano/smsir.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/common/siano/smsir.c b/drivers/media/common/siano/smsir.c
index 283770d583d5..636ff228108b 100644
--- a/drivers/media/common/siano/smsir.c
+++ b/drivers/media/common/siano/smsir.c
@@ -55,8 +55,8 @@ int sms_ir_init(struct smscore_device_t *coredev)
 	snprintf(coredev->ir.name, sizeof(coredev->ir.name),
 		 "SMS IR (%s)", sms_get_board(board_id)->name);
 
-	strscpy(coredev->ir.phys, coredev->devpath, sizeof(coredev->ir.phys));
-	strlcat(coredev->ir.phys, "/ir0", sizeof(coredev->ir.phys));
+	snprintf(coredev->ir.phys, sizeof(coredev->ir.phys),
+		 "%s/ir0", coredev->devpath);
 
 	dev->device_name = coredev->ir.name;
 	dev->input_phys = coredev->ir.phys;
-- 
2.43.0

Re: [PATCH] media: siano: Replace strlcat() with snprintf() in sms_ir_init()

[Alejandro Colomar]

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Hi Mariia,

> Date: 2026-11-04 01:02:39-0800
> From: Mariia Nikitash <nikitash.mariiaw@gmail.com>
>
> In preparation for removing the deprecated strlcat() API[1],
> replace the strscpy() and strlcat() calls with a single snprintf()
> call to construct the IR device path.
> 
> Both the source and destination buffers have the same capacity,

The line above seems irrelevant, and potentially confusing.
The size of the input is not important, because since we're appending
stuff after it, truncation may actually happen.

> and the return values are unused. This preserves the resulting
> string, including truncation behavior.
> 
> Link: https://github.com/KSPP/linux/issues/370 [1]
> Signed-off-by: Mariia Nikitash <nikitash.mariiaw@gmail.com>

Except for the small comment above,

Reviewed-by: Alejandro Colomar <alx@kernel.org>


Cheers,
Alex

> ---
>  drivers/media/common/siano/smsir.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/common/siano/smsir.c b/drivers/media/common/siano/smsir.c
> index 283770d583d5..636ff228108b 100644
> --- a/drivers/media/common/siano/smsir.c
> +++ b/drivers/media/common/siano/smsir.c
> @@ -55,8 +55,8 @@ int sms_ir_init(struct smscore_device_t *coredev)
>  	snprintf(coredev->ir.name, sizeof(coredev->ir.name),
>  		 "SMS IR (%s)", sms_get_board(board_id)->name);
>  
> -	strscpy(coredev->ir.phys, coredev->devpath, sizeof(coredev->ir.phys));
> -	strlcat(coredev->ir.phys, "/ir0", sizeof(coredev->ir.phys));
> +	snprintf(coredev->ir.phys, sizeof(coredev->ir.phys),
> +		 "%s/ir0", coredev->devpath);
>  
>  	dev->device_name = coredev->ir.name;
>  	dev->input_phys = coredev->ir.phys;
> -- 
> 2.43.0
> 
> 

-- 
<https://www.alejandro-colomar.es>

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Re: [PATCH] media: siano: Replace strlcat() with snprintf() in sms_ir_init()

[Shihuang Liu]

On Wed, Nov 04, 2026 at 01:02:39AM -0800, Mariia Nikitash wrote:
> In preparation for removing the deprecated strlcat() API[1],
> replace the strscpy() and strlcat() calls with a single snprintf()
> call to construct the IR device path.
> 
> Both the source and destination buffers have the same capacity,
> and the return values are unused. This preserves the resulting
> string, including truncation behavior.
> 
> Link: https://github.com/KSPP/linux/issues/370 [1]
> Signed-off-by: Mariia Nikitash <nikitash.mariiaw@gmail.com>

Reviewed-by: Shihuang Liu <shlomojune6@gmail.com>

[PATCH v2] media: siano: Replace strlcat() with snprintf() in sms_ir_init()

[Mariia Nikitash]

In preparation for removing the deprecated strlcat() API[1],
replace the strscpy() and strlcat() calls with a single snprintf()
call to construct the IR device path.

The return values are unused. This preserves the resulting
string, including truncation behavior.

Link: https://github.com/KSPP/linux/issues/370 [1]
Signed-off-by: Mariia Nikitash <nikitash.mariiaw@gmail.com>
Reviewed-by: Alejandro Colomar <alx@kernel.org>
Reviewed-by: Shihuang Liu <shlomojune6@gmail.com>
---

Changes in v2:
- No code changes.
- Remove the statement about buffer capacities
  from the commit message.
- Add Reviewed-by tags from Alejandro Colomar and Shihuang Liu.

 drivers/media/common/siano/smsir.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/common/siano/smsir.c b/drivers/media/common/siano/smsir.c
index 283770d583d5..636ff228108b 100644
--- a/drivers/media/common/siano/smsir.c
+++ b/drivers/media/common/siano/smsir.c
@@ -55,8 +55,8 @@ int sms_ir_init(struct smscore_device_t *coredev)
 	snprintf(coredev->ir.name, sizeof(coredev->ir.name),
 		 "SMS IR (%s)", sms_get_board(board_id)->name);
 
-	strscpy(coredev->ir.phys, coredev->devpath, sizeof(coredev->ir.phys));
-	strlcat(coredev->ir.phys, "/ir0", sizeof(coredev->ir.phys));
+	snprintf(coredev->ir.phys, sizeof(coredev->ir.phys),
+		 "%s/ir0", coredev->devpath);
 
 	dev->device_name = coredev->ir.name;
 	dev->input_phys = coredev->ir.phys;
-- 
2.43.0

Re: [PATCH] media: siano: Replace strlcat() with snprintf() in sms_ir_init()

[Mariia Nikitash]

On Wed, Nov 4, 2026 at 3:25 AM Alejandro Colomar
<alx+linux-hardening@kernel.org> wrote:
>
> Hi Mariia,

Hi Alejandro,

>
> > Date: 2026-11-04 01:02:39-0800
> > From: Mariia Nikitash <nikitash.mariiaw@gmail.com>
> >
> > In preparation for removing the deprecated strlcat() API[1],
> > replace the strscpy() and strlcat() calls with a single snprintf()
> > call to construct the IR device path.
> >
> > Both the source and destination buffers have the same capacity,
>
> The line above seems irrelevant, and potentially confusing.
> The size of the input is not important, because since we're appending
> stuff after it, truncation may actually happen.

Agreed. I've removed the statement about buffer capacities from the
commit message in v2. No code changes.


>
> > and the return values are unused. This preserves the resulting
> > string, including truncation behavior.
> >
> > Link: https://github.com/KSPP/linux/issues/370 [1]
> > Signed-off-by: Mariia Nikitash <nikitash.mariiaw@gmail.com>
>
> Except for the small comment above,
>
> Reviewed-by: Alejandro Colomar <alx@kernel.org>
>

Thanks for the review!

>
> Cheers,
> Alex
>

Best,
Mariia


> > ---
> >  drivers/media/common/siano/smsir.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/media/common/siano/smsir.c b/drivers/media/common/siano/smsir.c
> > index 283770d583d5..636ff228108b 100644
> > --- a/drivers/media/common/siano/smsir.c
> > +++ b/drivers/media/common/siano/smsir.c
> > @@ -55,8 +55,8 @@ int sms_ir_init(struct smscore_device_t *coredev)
> >       snprintf(coredev->ir.name, sizeof(coredev->ir.name),
> >                "SMS IR (%s)", sms_get_board(board_id)->name);
> >
> > -     strscpy(coredev->ir.phys, coredev->devpath, sizeof(coredev->ir.phys));
> > -     strlcat(coredev->ir.phys, "/ir0", sizeof(coredev->ir.phys));
> > +     snprintf(coredev->ir.phys, sizeof(coredev->ir.phys),
> > +              "%s/ir0", coredev->devpath);
> >
> >       dev->device_name = coredev->ir.name;
> >       dev->input_phys = coredev->ir.phys;
> > --
> > 2.43.0
> >
> >
>
> --
> <https://www.alejandro-colomar.es>