2023-06-13 01:15:33

by Azeem Shaikh

[permalink] [raw]
Subject: [PATCH] ieee802154: Replace 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().

Direct replacement is safe here since the return values
from the helper macros are ignored by the callers.

[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]>
---
net/ieee802154/trace.h | 2 +-
net/mac802154/trace.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ieee802154/trace.h b/net/ieee802154/trace.h
index e5d8439b9e45..c16db0b326fa 100644
--- a/net/ieee802154/trace.h
+++ b/net/ieee802154/trace.h
@@ -13,7 +13,7 @@

#define MAXNAME 32
#define WPAN_PHY_ENTRY __array(char, wpan_phy_name, MAXNAME)
-#define WPAN_PHY_ASSIGN strlcpy(__entry->wpan_phy_name, \
+#define WPAN_PHY_ASSIGN strscpy(__entry->wpan_phy_name, \
wpan_phy_name(wpan_phy), \
MAXNAME)
#define WPAN_PHY_PR_FMT "%s"
diff --git a/net/mac802154/trace.h b/net/mac802154/trace.h
index 689396d6c76a..1574ecc48075 100644
--- a/net/mac802154/trace.h
+++ b/net/mac802154/trace.h
@@ -14,7 +14,7 @@

#define MAXNAME 32
#define LOCAL_ENTRY __array(char, wpan_phy_name, MAXNAME)
-#define LOCAL_ASSIGN strlcpy(__entry->wpan_phy_name, \
+#define LOCAL_ASSIGN strscpy(__entry->wpan_phy_name, \
wpan_phy_name(local->hw.phy), MAXNAME)
#define LOCAL_PR_FMT "%s"
#define LOCAL_PR_ARG __entry->wpan_phy_name
--
2.41.0.162.gfafddb0af9-goog




2023-06-13 19:45:44

by Kees Cook

[permalink] [raw]
Subject: Re: [PATCH] ieee802154: Replace strlcpy with strscpy

On Tue, Jun 13, 2023 at 12:33:25AM +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().
>
> Direct replacement is safe here since the return values
> from the helper macros are ignored by the callers.
>
> [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 12:15:45

by Simon Horman

[permalink] [raw]
Subject: Re: [PATCH] ieee802154: Replace strlcpy with strscpy

On Tue, Jun 13, 2023 at 12:33:25AM +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().
>
> Direct replacement is safe here since the return values
> from the helper macros are ignored by the callers.
>
> [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: Simon Horman <[email protected]>


2023-06-16 22:07:35

by Stefan Schmidt

[permalink] [raw]
Subject: Re: [PATCH] ieee802154: Replace strlcpy with strscpy

Hello.

On 13.06.23 02:33, 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().
>
> Direct replacement is safe here since the return values
> from the helper macros are ignored by the callers.
>
> [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]>
> ---
> net/ieee802154/trace.h | 2 +-
> net/mac802154/trace.h | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/net/ieee802154/trace.h b/net/ieee802154/trace.h
> index e5d8439b9e45..c16db0b326fa 100644
> --- a/net/ieee802154/trace.h
> +++ b/net/ieee802154/trace.h
> @@ -13,7 +13,7 @@
>
> #define MAXNAME 32
> #define WPAN_PHY_ENTRY __array(char, wpan_phy_name, MAXNAME)
> -#define WPAN_PHY_ASSIGN strlcpy(__entry->wpan_phy_name, \
> +#define WPAN_PHY_ASSIGN strscpy(__entry->wpan_phy_name, \
> wpan_phy_name(wpan_phy), \
> MAXNAME)
> #define WPAN_PHY_PR_FMT "%s"
> diff --git a/net/mac802154/trace.h b/net/mac802154/trace.h
> index 689396d6c76a..1574ecc48075 100644
> --- a/net/mac802154/trace.h
> +++ b/net/mac802154/trace.h
> @@ -14,7 +14,7 @@
>
> #define MAXNAME 32
> #define LOCAL_ENTRY __array(char, wpan_phy_name, MAXNAME)
> -#define LOCAL_ASSIGN strlcpy(__entry->wpan_phy_name, \
> +#define LOCAL_ASSIGN strscpy(__entry->wpan_phy_name, \
> wpan_phy_name(local->hw.phy), MAXNAME)
> #define LOCAL_PR_FMT "%s"
> #define LOCAL_PR_ARG __entry->wpan_phy_name


This patch has been applied to the wpan tree and will be
part of the next pull request to net. Thanks!

regards
Stefan Schmidt