[PATCH 0/2] kyber, blk-wbt: Replace strlcpy with strscpy

[PATCH 0/2] kyber, blk-wbt: Replace strlcpy with strscpy

[Azeem Shaikh]

This patch series replaces strlcpy in the kyber and blk-wbt tracing subsystems wherever trivial
replacement is possible, i.e return value from strlcpy is unused. The patches
themselves are independent of each other and are applied to different subsystems. They are
included as a series for ease of review.

Note to reviewers: MAINTAINERS file does not specify clear ownership of
these files so I have addressed these to the latest committer for these
files: Jens Axboe <axboe@kernel.dk>.

Azeem Shaikh (2):
  kyber: Replace strlcpy with strscpy
  blk-wbt: Replace strlcpy with strscpy

 include/trace/events/kyber.h | 8 ++++----
 include/trace/events/wbt.h   | 8 ++++----
 2 files changed, 8 insertions(+), 8 deletions(-)

-- 
2.41.0.255.g8b1d071c50-goog

[PATCH 1/2] kyber: Replace strlcpy with strscpy

[Azeem Shaikh]

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>
---
 include/trace/events/kyber.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/trace/events/kyber.h b/include/trace/events/kyber.h
index bf7533f171ff..9d44781efc1c 100644
--- a/include/trace/events/kyber.h
+++ b/include/trace/events/kyber.h
@@ -31,8 +31,8 @@ TRACE_EVENT(kyber_latency,
 
 	TP_fast_assign(
 		__entry->dev		= dev;
-		strlcpy(__entry->domain, domain, sizeof(__entry->domain));
-		strlcpy(__entry->type, type, sizeof(__entry->type));
+		strscpy(__entry->domain, domain, sizeof(__entry->domain));
+		strscpy(__entry->type, type, sizeof(__entry->type));
 		__entry->percentile	= percentile;
 		__entry->numerator	= numerator;
 		__entry->denominator	= denominator;
@@ -59,7 +59,7 @@ TRACE_EVENT(kyber_adjust,
 
 	TP_fast_assign(
 		__entry->dev		= dev;
-		strlcpy(__entry->domain, domain, sizeof(__entry->domain));
+		strscpy(__entry->domain, domain, sizeof(__entry->domain));
 		__entry->depth		= depth;
 	),
 
@@ -81,7 +81,7 @@ TRACE_EVENT(kyber_throttled,
 
 	TP_fast_assign(
 		__entry->dev		= dev;
-		strlcpy(__entry->domain, domain, sizeof(__entry->domain));
+		strscpy(__entry->domain, domain, sizeof(__entry->domain));
 	),
 
 	TP_printk("%d,%d %s", MAJOR(__entry->dev), MINOR(__entry->dev),
-- 
2.41.0.255.g8b1d071c50-goog

[PATCH 2/2] blk-wbt: Replace strlcpy with strscpy

[Azeem Shaikh]

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>
---
 include/trace/events/wbt.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/trace/events/wbt.h b/include/trace/events/wbt.h
index 9c66e59d859c..4661f0d27062 100644
--- a/include/trace/events/wbt.h
+++ b/include/trace/events/wbt.h
@@ -33,7 +33,7 @@ TRACE_EVENT(wbt_stat,
 	),
 
 	TP_fast_assign(
-		strlcpy(__entry->name, bdi_dev_name(bdi),
+		strscpy(__entry->name, bdi_dev_name(bdi),
 			ARRAY_SIZE(__entry->name));
 		__entry->rmean		= stat[0].mean;
 		__entry->rmin		= stat[0].min;
@@ -68,7 +68,7 @@ TRACE_EVENT(wbt_lat,
 	),
 
 	TP_fast_assign(
-		strlcpy(__entry->name, bdi_dev_name(bdi),
+		strscpy(__entry->name, bdi_dev_name(bdi),
 			ARRAY_SIZE(__entry->name));
 		__entry->lat = div_u64(lat, 1000);
 	),
@@ -105,7 +105,7 @@ TRACE_EVENT(wbt_step,
 	),
 
 	TP_fast_assign(
-		strlcpy(__entry->name, bdi_dev_name(bdi),
+		strscpy(__entry->name, bdi_dev_name(bdi),
 			ARRAY_SIZE(__entry->name));
 		__entry->msg	= msg;
 		__entry->step	= step;
@@ -141,7 +141,7 @@ TRACE_EVENT(wbt_timer,
 	),
 
 	TP_fast_assign(
-		strlcpy(__entry->name, bdi_dev_name(bdi),
+		strscpy(__entry->name, bdi_dev_name(bdi),
 			ARRAY_SIZE(__entry->name));
 		__entry->status		= status;
 		__entry->step		= step;
-- 
2.41.0.255.g8b1d071c50-goog

Re: [PATCH 0/2] kyber, blk-wbt: Replace strlcpy with strscpy

[Kees Cook]

On Mon, Jul 03, 2023 at 05:21:57PM +0000, Azeem Shaikh wrote:
> This patch series replaces strlcpy in the kyber and blk-wbt tracing subsystems wherever trivial
> replacement is possible, i.e return value from strlcpy is unused. The patches
> themselves are independent of each other and are applied to different subsystems. They are
> included as a series for ease of review.
> 
> Note to reviewers: MAINTAINERS file does not specify clear ownership of
> these files so I have addressed these to the latest committer for these
> files: Jens Axboe <axboe@kernel.dk>.
> 
> Azeem Shaikh (2):
>   kyber: Replace strlcpy with strscpy
>   blk-wbt: Replace strlcpy with strscpy
> 
>  include/trace/events/kyber.h | 8 ++++----
>  include/trace/events/wbt.h   | 8 ++++----
>  2 files changed, 8 insertions(+), 8 deletions(-)

These looks correct to me. I can take them if no one else wants them.

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

-- 
Kees Cook

Re: [PATCH 0/2] kyber, blk-wbt: Replace strlcpy with strscpy

[Jens Axboe]

On Mon, 03 Jul 2023 17:21:57 +0000, Azeem Shaikh wrote:
> This patch series replaces strlcpy in the kyber and blk-wbt tracing subsystems wherever trivial
> replacement is possible, i.e return value from strlcpy is unused. The patches
> themselves are independent of each other and are applied to different subsystems. They are
> included as a series for ease of review.
> 
> Note to reviewers: MAINTAINERS file does not specify clear ownership of
> these files so I have addressed these to the latest committer for these
> files: Jens Axboe <axboe@kernel.dk>.
> 
> [...]

Applied, thanks!

[1/2] kyber: Replace strlcpy with strscpy
      commit: 150b5f497df6bdb4730cae1eb98f13017b2eef6c
[2/2] blk-wbt: Replace strlcpy with strscpy
      commit: 3abf6029341f2fd2ea6e48289662e8e4e3e96945

Best regards,
-- 
Jens Axboe