kyber: 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().
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>
Link: https://lore.kernel.org/r/20230703172159.3668349-2-azeemshaikh38@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/include/trace/events/kyber.h b/include/trace/events/kyber.h
index bf7533f171ff9c6542203d31599956227c11cc66..9d44781efc1c4ed0413516dd22f6511d5d937049 100644 (file)
--- 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),