2023-05-30 16:41:00

by Azeem Shaikh

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

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 <[email protected]>
---
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));



2023-05-30 23:33:43

by Kees Cook

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

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 <[email protected]>

Reviewed-by: Kees Cook <[email protected]>

--
Kees Cook

2023-06-14 18:54:09

by Kees Cook

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

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


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

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

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

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 <[email protected]>
> ---
> 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 <[email protected]>

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

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

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 <[email protected]>
> ---
> 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 <[email protected]>

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

2023-06-14 19:37:55

by Kees Cook

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

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

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

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

2023-06-14 19:47:11

by Kees Cook

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

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