[PATCH] sh: Replace all non-returning strlcpy with strscpy

From: Azeem Shaikh
Date: Tue May 30 2023 - 12:31:36 EST


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@xxxxxxxxx>
---
arch/sh/drivers/dma/dma-api.c | 2 +-
arch/sh/kernel/setup.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/sh/drivers/dma/dma-api.c b/arch/sh/drivers/dma/dma-api.c
index ab9170494dcc..89cd4a3b4cca 100644
--- a/arch/sh/drivers/dma/dma-api.c
+++ b/arch/sh/drivers/dma/dma-api.c
@@ -198,7 +198,7 @@ int request_dma(unsigned int chan, const char *dev_id)
if (atomic_xchg(&channel->busy, 1))
return -EBUSY;

- strlcpy(channel->dev_id, dev_id, sizeof(channel->dev_id));
+ strscpy(channel->dev_id, dev_id, sizeof(channel->dev_id));

if (info->ops->request) {
result = info->ops->request(channel);
diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
index af977ec4ca5e..e4f0f9a1d355 100644
--- a/arch/sh/kernel/setup.c
+++ b/arch/sh/kernel/setup.c
@@ -304,9 +304,9 @@ void __init setup_arch(char **cmdline_p)
bss_resource.end = virt_to_phys(__bss_stop)-1;

#ifdef CONFIG_CMDLINE_OVERWRITE
- strlcpy(command_line, CONFIG_CMDLINE, sizeof(command_line));
+ strscpy(command_line, CONFIG_CMDLINE, sizeof(command_line));
#else
- strlcpy(command_line, COMMAND_LINE, sizeof(command_line));
+ strscpy(command_line, COMMAND_LINE, sizeof(command_line));
#ifdef CONFIG_CMDLINE_EXTEND
strlcat(command_line, " ", sizeof(command_line));
strlcat(command_line, CONFIG_CMDLINE, sizeof(command_line));