`strncpy` is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces.
We expect both `kim_data->dev_name` and `kim_gdata->dev_name` to be NUL-terminated. `kim_data->dev_name` seems to not require NUL-padding. `kim_gdata` is already zero-allocated and as such does not require NUL-padding: | kim_gdata = kzalloc(sizeof(struct kim_data_s), GFP_KERNEL); Considering the above, a suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on the destination buffer without unnecessarily NUL-padding. Let's also opt to use the more idiomatic strscpy usage of: strscpy(dest, src, sizeof(dest)) Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt <justinst...@google.com> --- Changes in v2: - use sizeof(dest) (thanks Kees) - rebase onto mainline cbf3a2cb156a2c91 - Link to v1: https://lore.kernel.org/r/20230927-strncpy-drivers-misc-ti-st-st_kim-c-v1-1-29bbdeed1...@google.com --- Note: build-tested only. --- drivers/misc/ti-st/st_kim.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/misc/ti-st/st_kim.c b/drivers/misc/ti-st/st_kim.c index fe682e0553b2..4b1be0bb6ac0 100644 --- a/drivers/misc/ti-st/st_kim.c +++ b/drivers/misc/ti-st/st_kim.c @@ -590,7 +590,7 @@ static ssize_t store_dev_name(struct device *dev, { struct kim_data_s *kim_data = dev_get_drvdata(dev); pr_debug("storing dev name >%s<", buf); - strncpy(kim_data->dev_name, buf, count); + strscpy(kim_data->dev_name, buf, sizeof(kim_data->dev_name)); pr_debug("stored dev name >%s<", kim_data->dev_name); return count; } @@ -751,7 +751,8 @@ static int kim_probe(struct platform_device *pdev) } /* copying platform data */ - strncpy(kim_gdata->dev_name, pdata->dev_name, UART_DEV_NAME_LEN); + strscpy(kim_gdata->dev_name, pdata->dev_name, + sizeof(kim_gdata->dev_name)); kim_gdata->flow_cntrl = pdata->flow_cntrl; kim_gdata->baud_rate = pdata->baud_rate; pr_info("sysfs entries created\n"); --- base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2 change-id: 20230927-strncpy-drivers-misc-ti-st-st_kim-c-e1663a211a0c Best regards, -- Justin Stitt <justinst...@google.com>
