strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. These labels get copied out to the user so lets make sure they are NUL-terminated and NUL-padded. vparams is already memset to 0 so we don't need to do any NUL-padding (like what strncpy() is doing). 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: (dest, src, sizeof(dest)) as this more closely ties the destination buffer to the length. 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@xxxxxxxxxxxxxxx Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx> --- Note: build-tested only. Found with: $ rg "strncpy\(" --- drivers/scsi/ch.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/ch.c b/drivers/scsi/ch.c index cb0a399be1cc..2b864061e073 100644 --- a/drivers/scsi/ch.c +++ b/drivers/scsi/ch.c @@ -659,19 +659,23 @@ static long ch_ioctl(struct file *file, memset(&vparams,0,sizeof(vparams)); if (ch->counts[CHET_V1]) { vparams.cvp_n1 = ch->counts[CHET_V1]; - strncpy(vparams.cvp_label1,vendor_labels[0],16); + strscpy(vparams.cvp_label1, vendor_labels[0], + sizeof(vparams.cvp_label1)); } if (ch->counts[CHET_V2]) { vparams.cvp_n2 = ch->counts[CHET_V2]; - strncpy(vparams.cvp_label2,vendor_labels[1],16); + strscpy(vparams.cvp_label2, vendor_labels[1], + sizeof(vparams.cvp_label2)); } if (ch->counts[CHET_V3]) { vparams.cvp_n3 = ch->counts[CHET_V3]; - strncpy(vparams.cvp_label3,vendor_labels[2],16); + strscpy(vparams.cvp_label3, vendor_labels[2], + sizeof(vparams.cvp_label3)); } if (ch->counts[CHET_V4]) { vparams.cvp_n4 = ch->counts[CHET_V4]; - strncpy(vparams.cvp_label4,vendor_labels[3],16); + strscpy(vparams.cvp_label4, vendor_labels[3], + sizeof(vparams.cvp_label4)); } if (copy_to_user(argp, &vparams, sizeof(vparams))) return -EFAULT; --- base-commit: 9c5d00cb7b6bbc5a7965d9ab7d223b5402d1f02c change-id: 20231023-strncpy-drivers-scsi-ch-c-23b1cdac43cc Best regards, -- Justin Stitt <justinstitt@xxxxxxxxxx>
