Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Wang Xiayang <xywang.sjtu@sjtu.edu.cn>
Cc:     lftan@altera.com, rppt@linux.vnet.ibm.com,
        nios2-dev@lists.rocketboards.org, linux-kernel@vger.kernel.org,
        Wang Xiayang <xywang.sjtu@sjtu.edu.cn>
Subject: [PATCH] nios2: force the string buffer NULL-terminated
Date:   Mon,  5 Aug 2019 18:17:12 +0800
Message-Id: <20190805101712.22580-1-xywang.sjtu@sjtu.edu.cn>
To:     unlisted-recipients:; (no To-header on input)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

strncpy() does not ensure NULL-termination when the input string
size equals to the destination buffer size COMMAND_LINE_SIZE.
Besides, grep under arch/ with 'boot_command_line' shows
no other arch-specific code uses strncpy() when copying
boot_command_line.

Use strlcpy() instead.

This issue is identified by a Coccinelle script.

Signed-off-by: Wang Xiayang <xywang.sjtu@sjtu.edu.cn>
---
 arch/nios2/kernel/setup.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/nios2/kernel/setup.c b/arch/nios2/kernel/setup.c
index 6bbd4ae2beb0..4cf35b09c0ec 100644
--- a/arch/nios2/kernel/setup.c
+++ b/arch/nios2/kernel/setup.c
@@ -123,7 +123,7 @@ asmlinkage void __init nios2_boot_init(unsigned r4, unsigned r5, unsigned r6,
 		dtb_passed = r6;
 
 		if (r7)
-			strncpy(cmdline_passed, (char *)r7, COMMAND_LINE_SIZE);
+			strlcpy(cmdline_passed, (char *)r7, COMMAND_LINE_SIZE);
 	}
 #endif
 
@@ -131,10 +131,10 @@ asmlinkage void __init nios2_boot_init(unsigned r4, unsigned r5, unsigned r6,
 
 #ifndef CONFIG_CMDLINE_FORCE
 	if (cmdline_passed[0])
-		strncpy(boot_command_line, cmdline_passed, COMMAND_LINE_SIZE);
+		strlcpy(boot_command_line, cmdline_passed, COMMAND_LINE_SIZE);
 #ifdef CONFIG_NIOS2_CMDLINE_IGNORE_DTB
 	else
-		strncpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
+		strlcpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 #endif
 #endif
 
-- 
2.11.0