mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-23 20:24:12 +08:00
44900c3ee4
`strncpy` is deprecated for use on NUL-terminated destination strings [1]. A suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on its destination buffer argument which is _not_ always the case for `strncpy`! It should be noted that, in this case, the destination buffer has a length strictly greater than the source string. Moreover, the source string is NUL-terminated (and so is the destination) which means there was no real bug happening here. Nonetheless, this patch would get us one step closer to eliminating the `strncpy` API in the kernel, as its use is too ambiguous. We need to favor less ambiguous replacements such as: strscpy, strscpy_pad, strtomem and strtomem_pad (amongst others). Technically, my patch yields subtly different behavior. The original implementation with `strncpy` would fill the entire destination buffer with null bytes [3] while `strscpy` will leave the junk, uninitialized bytes trailing after the _mandatory_ NUL-termination. So, if somehow `pcm->name` or `card->driver/shortname/longname` require this NUL-padding behavior then `strscpy_pad` should be used. My interpretation, though, is that the aforementioned fields are just fine as NUL-terminated strings. Please correct my assumptions if needed and I'll send in a v2. [1]: www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [2]: manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [3]: https://linux.die.net/man/3/strncpy Link: https://github.com/KSPP/linux/issues/90 Signed-off-by: Justin Stitt <justinstitt@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230727-sound-xen-v1-1-89dd161351f1@google.com Signed-off-by: Takashi Iwai <tiwai@suse.de> |
||
|---|---|---|
| .. | ||
| Kconfig | ||
| Makefile | ||
| xen_snd_front_alsa.c | ||
| xen_snd_front_alsa.h | ||
| xen_snd_front_cfg.c | ||
| xen_snd_front_cfg.h | ||
| xen_snd_front_evtchnl.c | ||
| xen_snd_front_evtchnl.h | ||
| xen_snd_front.c | ||
| xen_snd_front.h | ||