[PATCH] nios2: force the string buffer NULL-terminated

From: Wang Xiayang
Date: Mon Aug 05 2019 - 06:17:21 EST


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@xxxxxxxxxxx>
---
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