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 nc->if_name to be NUL-terminated based on existing manual NUL-byte assignments and checks: | nc.if_name[IFNAMSIZ-1] = '\0'; ... | if (nc->if_name[0] != '\0') Let's use the new 2-argument strscpy() since it guarantees NUL-termination on the destination buffer while correctly using the destination buffers size to bound the operation. 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/tty/n_gsm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 4036566febcb..f5b0d91d32a7 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -4010,7 +4010,7 @@ static int gsm_create_network(struct gsm_dlci *dlci, struct gsm_netconfig *nc) mux_net = netdev_priv(net); mux_net->dlci = dlci; kref_init(&mux_net->ref); - strncpy(nc->if_name, net->name, IFNAMSIZ); /* return net name */ + strscpy(nc->if_name, net->name); /* return net name */ /* reconfigure dlci for network */ dlci->prev_adaption = dlci->adaption; --- base-commit: bf3a69c6861ff4dc7892d895c87074af7bc1c400 change-id: 20240318-strncpy-drivers-tty-n_gsm-c-ab1336e0e196 Best regards, -- Justin Stitt <justinstitt@xxxxxxxxxx>
