[PATCH v3 4/4] um: Convert strscpy() usage to 2-argument style

From: Kees Cook
Date: Tue Feb 06 2024 - 09:23:03 EST


The ARCH=um build has its own idea about strscpy()'s definition. Adjust
the callers to remove the redundant sizeof() arguments ahead of treewide
changes, since it needs a manual adjustment for the newly named
sized_strscpy() export.

Cc: Richard Weinberger <richard@xxxxxx>
Cc: linux-um@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
arch/um/drivers/net_kern.c | 2 +-
arch/um/drivers/vector_kern.c | 2 +-
arch/um/drivers/vector_user.c | 4 ++--
arch/um/include/shared/user.h | 2 +-
arch/um/os-Linux/drivers/ethertap_user.c | 2 +-
arch/um/os-Linux/drivers/tuntap_user.c | 2 +-
arch/um/os-Linux/umid.c | 6 +++---
7 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index cabcc501b448..77c4afb8ab90 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -265,7 +265,7 @@ static void uml_net_poll_controller(struct net_device *dev)
static void uml_net_get_drvinfo(struct net_device *dev,
struct ethtool_drvinfo *info)
{
- strscpy(info->driver, DRIVER_NAME, sizeof(info->driver));
+ strscpy(info->driver, DRIVER_NAME);
}

static const struct ethtool_ops uml_net_ethtool_ops = {
diff --git a/arch/um/drivers/vector_kern.c b/arch/um/drivers/vector_kern.c
index 131b7cb29576..dc2feae789cb 100644
--- a/arch/um/drivers/vector_kern.c
+++ b/arch/um/drivers/vector_kern.c
@@ -1373,7 +1373,7 @@ static void vector_net_poll_controller(struct net_device *dev)
static void vector_net_get_drvinfo(struct net_device *dev,
struct ethtool_drvinfo *info)
{
- strscpy(info->driver, DRIVER_NAME, sizeof(info->driver));
+ strscpy(info->driver, DRIVER_NAME);
}

static int vector_net_load_bpf_flash(struct net_device *dev,
diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index c719e1ec4645..b16a5e5619d3 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -141,7 +141,7 @@ static int create_tap_fd(char *iface)
}
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR;
- strscpy(ifr.ifr_name, iface, sizeof(ifr.ifr_name));
+ strscpy(ifr.ifr_name, iface);

err = ioctl(fd, TUNSETIFF, (void *) &ifr);
if (err != 0) {
@@ -171,7 +171,7 @@ static int create_raw_fd(char *iface, int flags, int proto)
goto raw_fd_cleanup;
}
memset(&ifr, 0, sizeof(ifr));
- strscpy(ifr.ifr_name, iface, sizeof(ifr.ifr_name));
+ strscpy(ifr.ifr_name, iface);
if (ioctl(fd, SIOCGIFINDEX, (void *) &ifr) < 0) {
err = -errno;
goto raw_fd_cleanup;
diff --git a/arch/um/include/shared/user.h b/arch/um/include/shared/user.h
index 9568cc04cbb7..326e52450e41 100644
--- a/arch/um/include/shared/user.h
+++ b/arch/um/include/shared/user.h
@@ -52,7 +52,7 @@ static inline int printk(const char *fmt, ...)
extern int in_aton(char *str);
extern size_t strlcat(char *, const char *, size_t);
extern size_t sized_strscpy(char *, const char *, size_t);
-#define strscpy(dst, src, size) sized_strscpy(dst, src, size)
+#define strscpy(dst, src) sized_strscpy(dst, src, sizeof(dst))

/* Copied from linux/compiler-gcc.h since we can't include it directly */
#define barrier() __asm__ __volatile__("": : :"memory")
diff --git a/arch/um/os-Linux/drivers/ethertap_user.c b/arch/um/os-Linux/drivers/ethertap_user.c
index 3363851a4ae8..bdf215c0eca7 100644
--- a/arch/um/os-Linux/drivers/ethertap_user.c
+++ b/arch/um/os-Linux/drivers/ethertap_user.c
@@ -105,7 +105,7 @@ static int etap_tramp(char *dev, char *gate, int control_me,
sprintf(data_fd_buf, "%d", data_remote);
sprintf(version_buf, "%d", UML_NET_VERSION);
if (gate != NULL) {
- strscpy(gate_buf, gate, sizeof(gate_buf));
+ strscpy(gate_buf, gate);
args = setup_args;
}
else args = nosetup_args;
diff --git a/arch/um/os-Linux/drivers/tuntap_user.c b/arch/um/os-Linux/drivers/tuntap_user.c
index 2284e9c1cbbb..91f0e27ca3a6 100644
--- a/arch/um/os-Linux/drivers/tuntap_user.c
+++ b/arch/um/os-Linux/drivers/tuntap_user.c
@@ -146,7 +146,7 @@ static int tuntap_open(void *data)
}
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
- strscpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name));
+ strscpy(ifr.ifr_name, pri->dev_name);
if (ioctl(pri->fd, TUNSETIFF, &ifr) < 0) {
err = -errno;
printk(UM_KERN_ERR "TUNSETIFF failed, errno = %d\n",
diff --git a/arch/um/os-Linux/umid.c b/arch/um/os-Linux/umid.c
index 288c422bfa96..e09d65b05d1c 100644
--- a/arch/um/os-Linux/umid.c
+++ b/arch/um/os-Linux/umid.c
@@ -40,7 +40,7 @@ static int __init make_uml_dir(void)
__func__);
goto err;
}
- strscpy(dir, home, sizeof(dir));
+ strscpy(dir, home);
uml_dir++;
}
strlcat(dir, uml_dir, sizeof(dir));
@@ -243,7 +243,7 @@ int __init set_umid(char *name)
if (strlen(name) > UMID_LEN - 1)
return -E2BIG;

- strscpy(umid, name, sizeof(umid));
+ strscpy(umid, name);

return 0;
}
@@ -262,7 +262,7 @@ static int __init make_umid(void)
make_uml_dir();

if (*umid == '\0') {
- strscpy(tmp, uml_dir, sizeof(tmp));
+ strscpy(tmp, uml_dir);
strlcat(tmp, "XXXXXX", sizeof(tmp));
fd = mkstemp(tmp);
if (fd < 0) {
--
2.34.1