While replacing strncpy() with strscpy(), Bart Van Assche pointed out that the code occurs inside sysfs write callbacks, which already uses NUL-terminated strings. This allows the string to be passed directly to sscanf() without requiring a temporary copy.
Remove the deprecated and unnecessary strncpy() and the corresponding local variables, and pass the buffer buf directly to sscanf(). Replace sscanf() with kstrtoint() to silence checkpatch warnings. Compile-tested only. Link: https://github.com/KSPP/linux/issues/90 Cc: [email protected] Cc: Kees Cook <[email protected]> Cc: David Laight <[email protected]> Suggested-by: Bart Van Assche <[email protected]> Signed-off-by: Thorsten Blum <[email protected]> --- Changes in v2: - Adjust len to copy the same number of bytes as with strncpy() - Link to v1: https://lore.kernel.org/r/[email protected]/ Changes in v3: - Remove strncpy() and tmpbuf et al and use buf directly as suggested by Bart Van Assche and Kees Cook - Replace sscanf() with kstrtoint() as suggested by David Laight - Link to v2: https://lore.kernel.org/linux-kernel/[email protected]/ --- drivers/scsi/hpsa.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index 84d8de07b7ae..bb65954b1b1e 100644 --- a/drivers/scsi/hpsa.c +++ b/drivers/scsi/hpsa.c @@ -453,17 +453,13 @@ static ssize_t host_store_hp_ssd_smart_path_status(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int status, len; + int status; struct ctlr_info *h; struct Scsi_Host *shost = class_to_shost(dev); - char tmpbuf[10]; if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) return -EACCES; - len = count > sizeof(tmpbuf) - 1 ? sizeof(tmpbuf) - 1 : count; - strncpy(tmpbuf, buf, len); - tmpbuf[len] = '\0'; - if (sscanf(tmpbuf, "%d", &status) != 1) + if (kstrtoint(buf, 10, &status)) return -EINVAL; h = shost_to_hba(shost); h->acciopath_status = !!status; @@ -477,17 +473,13 @@ static ssize_t host_store_raid_offload_debug(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int debug_level, len; + int debug_level; struct ctlr_info *h; struct Scsi_Host *shost = class_to_shost(dev); - char tmpbuf[10]; if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) return -EACCES; - len = count > sizeof(tmpbuf) - 1 ? sizeof(tmpbuf) - 1 : count; - strncpy(tmpbuf, buf, len); - tmpbuf[len] = '\0'; - if (sscanf(tmpbuf, "%d", &debug_level) != 1) + if (kstrtoint(buf, 10, &debug_level)) return -EINVAL; if (debug_level < 0) debug_level = 0; -- 2.48.1
