[PATCH] riscv: use strscpy to replace strlcpy

Jason Wang wangborong at cdjrlc.com
Sat Aug 7 00:14:27 PDT 2021


The strlcpy should not be used because it doesn't limit the source
length. As linus says, it's a completely useless function if you
can't implicitly trust the source string - but that is almost always
why people think they should use it! All in all the BSD function
will lead some potential bugs.

But the strscpy doesn't require reading memory from the src string
beyond the specified "count" bytes, and since the return value is
easier to error-check than strlcpy()'s. In addition, the implementation
is robust to the string changing out from underneath it, unlike the
current strlcpy() implementation.

Thus, We prefer using strscpy instead of strlcpy.

Signed-off-by: Jason Wang <wangborong at cdjrlc.com>
---
 arch/riscv/kernel/setup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 18bd0e4bc36c..2dc62ebc0001 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -255,7 +255,7 @@ static void __init parse_dtb(void)
 
 	pr_err("No DTB passed to the kernel\n");
 #ifdef CONFIG_CMDLINE_FORCE
-	strlcpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
+	strscpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 	pr_info("Forcing kernel command line to: %s\n", boot_command_line);
 #endif
 }
-- 
2.32.0






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