sh: Replace all non-returning strlcpy with strscpy

[PATCH] sh: Replace all non-returning strlcpy with strscpy

Posted by Azeem Shaikh 2 years, 8 months ago

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
---
 arch/sh/drivers/dma/dma-api.c |    2 +-
 arch/sh/kernel/setup.c        |    4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/sh/drivers/dma/dma-api.c b/arch/sh/drivers/dma/dma-api.c
index ab9170494dcc..89cd4a3b4cca 100644
--- a/arch/sh/drivers/dma/dma-api.c
+++ b/arch/sh/drivers/dma/dma-api.c
@@ -198,7 +198,7 @@ int request_dma(unsigned int chan, const char *dev_id)
 	if (atomic_xchg(&channel->busy, 1))
 		return -EBUSY;
 
-	strlcpy(channel->dev_id, dev_id, sizeof(channel->dev_id));
+	strscpy(channel->dev_id, dev_id, sizeof(channel->dev_id));
 
 	if (info->ops->request) {
 		result = info->ops->request(channel);
diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
index af977ec4ca5e..e4f0f9a1d355 100644
--- a/arch/sh/kernel/setup.c
+++ b/arch/sh/kernel/setup.c
@@ -304,9 +304,9 @@ void __init setup_arch(char **cmdline_p)
 	bss_resource.end = virt_to_phys(__bss_stop)-1;
 
 #ifdef CONFIG_CMDLINE_OVERWRITE
-	strlcpy(command_line, CONFIG_CMDLINE, sizeof(command_line));
+	strscpy(command_line, CONFIG_CMDLINE, sizeof(command_line));
 #else
-	strlcpy(command_line, COMMAND_LINE, sizeof(command_line));
+	strscpy(command_line, COMMAND_LINE, sizeof(command_line));
 #ifdef CONFIG_CMDLINE_EXTEND
 	strlcat(command_line, " ", sizeof(command_line));
 	strlcat(command_line, CONFIG_CMDLINE, sizeof(command_line));

Re: [PATCH] sh: Replace all non-returning strlcpy with strscpy

Posted by John Paul Adrian Glaubitz 2 years, 7 months ago

On Tue, 2023-05-30 at 16:30 +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> No return values were used, so direct replacement is safe.
> 
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> [2] https://github.com/KSPP/linux/issues/89
> 
> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
> ---
>  arch/sh/drivers/dma/dma-api.c |    2 +-
>  arch/sh/kernel/setup.c        |    4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/sh/drivers/dma/dma-api.c b/arch/sh/drivers/dma/dma-api.c
> index ab9170494dcc..89cd4a3b4cca 100644
> --- a/arch/sh/drivers/dma/dma-api.c
> +++ b/arch/sh/drivers/dma/dma-api.c
> @@ -198,7 +198,7 @@ int request_dma(unsigned int chan, const char *dev_id)
>  	if (atomic_xchg(&channel->busy, 1))
>  		return -EBUSY;
>  
> -	strlcpy(channel->dev_id, dev_id, sizeof(channel->dev_id));
> +	strscpy(channel->dev_id, dev_id, sizeof(channel->dev_id));
>  
>  	if (info->ops->request) {
>  		result = info->ops->request(channel);
> diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
> index af977ec4ca5e..e4f0f9a1d355 100644
> --- a/arch/sh/kernel/setup.c
> +++ b/arch/sh/kernel/setup.c
> @@ -304,9 +304,9 @@ void __init setup_arch(char **cmdline_p)
>  	bss_resource.end = virt_to_phys(__bss_stop)-1;
>  
>  #ifdef CONFIG_CMDLINE_OVERWRITE
> -	strlcpy(command_line, CONFIG_CMDLINE, sizeof(command_line));
> +	strscpy(command_line, CONFIG_CMDLINE, sizeof(command_line));
>  #else
> -	strlcpy(command_line, COMMAND_LINE, sizeof(command_line));
> +	strscpy(command_line, COMMAND_LINE, sizeof(command_line));
>  #ifdef CONFIG_CMDLINE_EXTEND
>  	strlcat(command_line, " ", sizeof(command_line));
>  	strlcat(command_line, CONFIG_CMDLINE, sizeof(command_line));

Acked-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer
`. `'   Physicist
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913

Re: [PATCH] sh: Replace all non-returning strlcpy with strscpy

Posted by John Paul Adrian Glaubitz 2 years, 7 months ago

On Tue, 2023-05-30 at 16:30 +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> No return values were used, so direct replacement is safe.
> 
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> [2] https://github.com/KSPP/linux/issues/89
> 
> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
> ---
>  arch/sh/drivers/dma/dma-api.c |    2 +-
>  arch/sh/kernel/setup.c        |    4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/sh/drivers/dma/dma-api.c b/arch/sh/drivers/dma/dma-api.c
> index ab9170494dcc..89cd4a3b4cca 100644
> --- a/arch/sh/drivers/dma/dma-api.c
> +++ b/arch/sh/drivers/dma/dma-api.c
> @@ -198,7 +198,7 @@ int request_dma(unsigned int chan, const char *dev_id)
>  	if (atomic_xchg(&channel->busy, 1))
>  		return -EBUSY;
>  
> -	strlcpy(channel->dev_id, dev_id, sizeof(channel->dev_id));
> +	strscpy(channel->dev_id, dev_id, sizeof(channel->dev_id));
>  
>  	if (info->ops->request) {
>  		result = info->ops->request(channel);
> diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
> index af977ec4ca5e..e4f0f9a1d355 100644
> --- a/arch/sh/kernel/setup.c
> +++ b/arch/sh/kernel/setup.c
> @@ -304,9 +304,9 @@ void __init setup_arch(char **cmdline_p)
>  	bss_resource.end = virt_to_phys(__bss_stop)-1;
>  
>  #ifdef CONFIG_CMDLINE_OVERWRITE
> -	strlcpy(command_line, CONFIG_CMDLINE, sizeof(command_line));
> +	strscpy(command_line, CONFIG_CMDLINE, sizeof(command_line));
>  #else
> -	strlcpy(command_line, COMMAND_LINE, sizeof(command_line));
> +	strscpy(command_line, COMMAND_LINE, sizeof(command_line));
>  #ifdef CONFIG_CMDLINE_EXTEND
>  	strlcat(command_line, " ", sizeof(command_line));
>  	strlcat(command_line, CONFIG_CMDLINE, sizeof(command_line));

Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer
`. `'   Physicist
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913

Re: [PATCH] sh: Replace all non-returning strlcpy with strscpy

Posted by Kees Cook 2 years, 7 months ago

On Tue, 30 May 2023 16:30:41 +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> No return values were used, so direct replacement is safe.
> 
> [...]

Build tested with sh4 GCC 13.1 from:
https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/13.1.0/

with defconfig and:
	CONFIG_CPU_SUBTYPE_SH7343=y
	CONFIG_SH_DMA=y
	CONFIG_SH_DMA_API=y

Applied to for-next/hardening, thanks!

[1/1] sh: Replace all non-returning strlcpy with strscpy
      https://git.kernel.org/kees/c/ca64da3052be

-- 
Kees Cook

Re: [PATCH] sh: Replace all non-returning strlcpy with strscpy

Posted by John Paul Adrian Glaubitz 2 years, 7 months ago

Hi Kees!

On Wed, 2023-06-14 at 11:44 -0700, Kees Cook wrote:
> On Tue, 30 May 2023 16:30:41 +0000, Azeem Shaikh wrote:
> > strlcpy() reads the entire source buffer first.
> > This read may exceed the destination size limit.
> > This is both inefficient and can lead to linear read
> > overflows if a source string is not NUL-terminated [1].
> > In an effort to remove strlcpy() completely [2], replace
> > strlcpy() here with strscpy().
> > No return values were used, so direct replacement is safe.
> > 
> > [...]
> 
> Build tested with sh4 GCC 13.1 from:
> https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/13.1.0/
> 
> with defconfig and:
> 	CONFIG_CPU_SUBTYPE_SH7343=y
> 	CONFIG_SH_DMA=y
> 	CONFIG_SH_DMA_API=y
> 
> Applied to for-next/hardening, thanks!
> 
> [1/1] sh: Replace all non-returning strlcpy with strscpy
>       https://git.kernel.org/kees/c/ca64da3052be
> 

Apologies, this fell off my table. I should have acked and tested this being the
SuperH maintainer. If you can still update the patch in your tree, I can both
test and ack this patch.

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer
`. `'   Physicist
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913

Re: [PATCH] sh: Replace all non-returning strlcpy with strscpy

Posted by Kees Cook 2 years, 7 months ago

On Wed, Jun 14, 2023 at 08:49:13PM +0200, John Paul Adrian Glaubitz wrote:
> Hi Kees!
> 
> On Wed, 2023-06-14 at 11:44 -0700, Kees Cook wrote:
> > On Tue, 30 May 2023 16:30:41 +0000, Azeem Shaikh wrote:
> > > strlcpy() reads the entire source buffer first.
> > > This read may exceed the destination size limit.
> > > This is both inefficient and can lead to linear read
> > > overflows if a source string is not NUL-terminated [1].
> > > In an effort to remove strlcpy() completely [2], replace
> > > strlcpy() here with strscpy().
> > > No return values were used, so direct replacement is safe.
> > > 
> > > [...]
> > 
> > Build tested with sh4 GCC 13.1 from:
> > https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/13.1.0/
> > 
> > with defconfig and:
> > 	CONFIG_CPU_SUBTYPE_SH7343=y
> > 	CONFIG_SH_DMA=y
> > 	CONFIG_SH_DMA_API=y
> > 
> > Applied to for-next/hardening, thanks!
> > 
> > [1/1] sh: Replace all non-returning strlcpy with strscpy
> >       https://git.kernel.org/kees/c/ca64da3052be
> > 
> 
> Apologies, this fell off my table. I should have acked and tested this being the
> SuperH maintainer. If you can still update the patch in your tree, I can both
> test and ack this patch.

Absolutely! Thanks for double-checking. :)

-Kees

-- 
Kees Cook

Re: [PATCH] sh: Replace all non-returning strlcpy with strscpy

Posted by John Paul Adrian Glaubitz 2 years, 7 months ago

On Wed, 2023-06-14 at 12:03 -0700, Kees Cook wrote:
> On Wed, Jun 14, 2023 at 08:49:13PM +0200, John Paul Adrian Glaubitz wrote:
> > Hi Kees!
> > 
> > On Wed, 2023-06-14 at 11:44 -0700, Kees Cook wrote:
> > > On Tue, 30 May 2023 16:30:41 +0000, Azeem Shaikh wrote:
> > > > strlcpy() reads the entire source buffer first.
> > > > This read may exceed the destination size limit.
> > > > This is both inefficient and can lead to linear read
> > > > overflows if a source string is not NUL-terminated [1].
> > > > In an effort to remove strlcpy() completely [2], replace
> > > > strlcpy() here with strscpy().
> > > > No return values were used, so direct replacement is safe.
> > > > 
> > > > [...]
> > > 
> > > Build tested with sh4 GCC 13.1 from:
> > > https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/13.1.0/
> > > 
> > > with defconfig and:
> > > 	CONFIG_CPU_SUBTYPE_SH7343=y
> > > 	CONFIG_SH_DMA=y
> > > 	CONFIG_SH_DMA_API=y
> > > 
> > > Applied to for-next/hardening, thanks!
> > > 
> > > [1/1] sh: Replace all non-returning strlcpy with strscpy
> > >       https://git.kernel.org/kees/c/ca64da3052be
> > > 
> > 
> > Apologies, this fell off my table. I should have acked and tested this being the
> > SuperH maintainer. If you can still update the patch in your tree, I can both
> > test and ack this patch.
> 
> Absolutely! Thanks for double-checking. :)

I have tested the patch on my SH-7785LCR board on top of Linus' tree and
also acked it.

Thanks,
Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer
`. `'   Physicist
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913

Re: [PATCH] sh: Replace all non-returning strlcpy with strscpy

Posted by Kees Cook 2 years, 7 months ago

On Wed, Jun 14, 2023 at 09:23:49PM +0200, John Paul Adrian Glaubitz wrote:
> On Wed, 2023-06-14 at 12:03 -0700, Kees Cook wrote:
> > On Wed, Jun 14, 2023 at 08:49:13PM +0200, John Paul Adrian Glaubitz wrote:
> > > Hi Kees!
> > > 
> > > On Wed, 2023-06-14 at 11:44 -0700, Kees Cook wrote:
> > > > On Tue, 30 May 2023 16:30:41 +0000, Azeem Shaikh wrote:
> > > > > strlcpy() reads the entire source buffer first.
> > > > > This read may exceed the destination size limit.
> > > > > This is both inefficient and can lead to linear read
> > > > > overflows if a source string is not NUL-terminated [1].
> > > > > In an effort to remove strlcpy() completely [2], replace
> > > > > strlcpy() here with strscpy().
> > > > > No return values were used, so direct replacement is safe.
> > > > > 
> > > > > [...]
> > > > 
> > > > Build tested with sh4 GCC 13.1 from:
> > > > https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/13.1.0/
> > > > 
> > > > with defconfig and:
> > > > 	CONFIG_CPU_SUBTYPE_SH7343=y
> > > > 	CONFIG_SH_DMA=y
> > > > 	CONFIG_SH_DMA_API=y
> > > > 
> > > > Applied to for-next/hardening, thanks!
> > > > 
> > > > [1/1] sh: Replace all non-returning strlcpy with strscpy
> > > >       https://git.kernel.org/kees/c/ca64da3052be
> > > > 
> > > 
> > > Apologies, this fell off my table. I should have acked and tested this being the
> > > SuperH maintainer. If you can still update the patch in your tree, I can both
> > > test and ack this patch.
> > 
> > Absolutely! Thanks for double-checking. :)
> 
> I have tested the patch on my SH-7785LCR board on top of Linus' tree and
> also acked it.

Awesome. :) I have updated the tags and will push out my tree shortly.

Thanks!

-Kees

-- 
Kees Cook

Re: [PATCH] sh: Replace all non-returning strlcpy with strscpy

Posted by Kees Cook 2 years, 8 months ago

On Tue, May 30, 2023 at 04:30:41PM +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> No return values were used, so direct replacement is safe.
> 
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> [2] https://github.com/KSPP/linux/issues/89
> 
> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook