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From:   Azeem Shaikh <azeemshaikh38@gmail.com>
To:     Dinh Nguyen <dinguyen@kernel.org>
Cc:     linux-hardening@vger.kernel.org,
        Azeem Shaikh <azeemshaikh38@gmail.com>,
        linux-kernel@vger.kernel.org
Subject: [PATCH] nios2: Replace all non-returning strlcpy with strscpy
Date:   Tue, 30 May 2023 16:23:58 +0000
Message-ID: <20230530162358.984149-1-azeemshaikh38@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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>
---
 arch/nios2/kernel/cpuinfo.c |    2 +-
 arch/nios2/kernel/setup.c   |    6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/nios2/kernel/cpuinfo.c b/arch/nios2/kernel/cpuinfo.c
index 203870c4b86d..338849c430a5 100644
--- a/arch/nios2/kernel/cpuinfo.c
+++ b/arch/nios2/kernel/cpuinfo.c
@@ -47,7 +47,7 @@ void __init setup_cpuinfo(void)
 
 	str = of_get_property(cpu, "altr,implementation", &len);
 	if (str)
-		strlcpy(cpuinfo.cpu_impl, str, sizeof(cpuinfo.cpu_impl));
+		strscpy(cpuinfo.cpu_impl, str, sizeof(cpuinfo.cpu_impl));
 	else
 		strcpy(cpuinfo.cpu_impl, "<unknown>");
 
diff --git a/arch/nios2/kernel/setup.c b/arch/nios2/kernel/setup.c
index 40bc8fb75e0b..8582ed965844 100644
--- a/arch/nios2/kernel/setup.c
+++ b/arch/nios2/kernel/setup.c
@@ -121,7 +121,7 @@ asmlinkage void __init nios2_boot_init(unsigned r4, unsigned r5, unsigned r6,
 		dtb_passed = r6;
 
 		if (r7)
-			strlcpy(cmdline_passed, (char *)r7, COMMAND_LINE_SIZE);
+			strscpy(cmdline_passed, (char *)r7, COMMAND_LINE_SIZE);
 	}
 #endif
 
@@ -129,10 +129,10 @@ asmlinkage void __init nios2_boot_init(unsigned r4, unsigned r5, unsigned r6,
 
 #ifndef CONFIG_CMDLINE_FORCE
 	if (cmdline_passed[0])
-		strlcpy(boot_command_line, cmdline_passed, COMMAND_LINE_SIZE);
+		strscpy(boot_command_line, cmdline_passed, COMMAND_LINE_SIZE);
 #ifdef CONFIG_NIOS2_CMDLINE_IGNORE_DTB
 	else
-		strlcpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
+		strscpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 #endif
 #endif