diff options
| author | Azeem Shaikh <azeemshaikh38@gmail.com> | 2023-06-14 00:36:04 +0000 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2023-06-20 13:35:37 -0700 |
| commit | f0a6b5831cfb17381ada015778448b12c1c6179e (patch) | |
| tree | 301292e964a596828cbbe8b4a3066225b4f8cdd5 /arch | |
| parent | a5a319ec2c2236bb96d147c16196d2f1f3799301 (diff) | |
uml: Replace strlcpy with strscpy
strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230614003604.1021205-1-azeemshaikh38@gmail.com
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/um/include/shared/user.h | 1 | ||||
| -rw-r--r-- | arch/um/os-Linux/drivers/tuntap_user.c | 2 |
2 files changed, 2 insertions, 1 deletions
diff --git a/arch/um/include/shared/user.h b/arch/um/include/shared/user.h index bda66e5a9d4e..0347a190429c 100644 --- a/arch/um/include/shared/user.h +++ b/arch/um/include/shared/user.h @@ -52,6 +52,7 @@ static inline int printk(const char *fmt, ...) extern int in_aton(char *str); extern size_t strlcpy(char *, const char *, size_t); extern size_t strlcat(char *, const char *, size_t); +extern size_t strscpy(char *, const char *, size_t); /* 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/tuntap_user.c b/arch/um/os-Linux/drivers/tuntap_user.c index 53eb3d508645..2284e9c1cbbb 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; - strlcpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name)); + strscpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name)); if (ioctl(pri->fd, TUNSETIFF, &ifr) < 0) { err = -errno; printk(UM_KERN_ERR "TUNSETIFF failed, errno = %d\n", |