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From:   Azeem Shaikh <azeemshaikh38@gmail.com>
To:     Kees Cook <keescook@chromium.org>, Jens Axboe <axboe@kernel.dk>
Cc:     linux-hardening@vger.kernel.org,
        Azeem Shaikh <azeemshaikh38@gmail.com>,
        linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
        Steven Rostedt <rostedt@goodmis.org>
Subject: [PATCH 1/2] kyber: Replace strlcpy with strscpy
Date:   Mon,  3 Jul 2023 17:21:58 +0000
Message-ID: <20230703172159.3668349-2-azeemshaikh38@gmail.com>
In-Reply-To: <20230703172159.3668349-1-azeemshaikh38@gmail.com>
References: <20230703172159.3668349-1-azeemshaikh38@gmail.com>
MIME-Version: 1.0
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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