Justin Stitt <justinstitt@xxxxxxxxxx> wrote: > strncpy() is deprecated for use on NUL-terminated destination strings > [1] and as such we should prefer more robust and less ambiguous string > interfaces. > > `extra` is intended to be NUL-terminated which is evident by the manual > assignment of a NUL-byte as well as its immediate usage with strlen(). > > Moreover, many of these getters and setters are NUL-padding buffers with > memset(): > 2439 | memset(&tx_power, 0, sizeof(tx_power)); > 9998 | memset(sys_config, 0, sizeof(struct ipw_sys_config)); > 10084 | memset(tfd, 0, sizeof(*tfd)); > 10261 | memset(&dummystats, 0, sizeof(dummystats)); > ... let's maintain this behavior and NUL-pad our destination buffer. > > Considering the above, a suitable replacement is `strscpy_pad` due to > the fact that it guarantees both NUL-termination and NUL-padding on the > destination buffer. > > To be clear, there is no bug in the current implementation as > MAX_WX_STRING is much larger than the size of the string literals being > copied from. Also, strncpy() does NUL-pad the destination buffer and > using strscpy_pad() simply matches that behavior. All in all, there > should be no functional change but we are one step closer to eliminating > usage of strncpy(). > > Do note that we cannot use the more idiomatic strscpy invocation of > (dest, src, sizeof(dest)) as the destination buffer cannot have its size > determined at compile time. So, let's stick with (dest, src, LEN). > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@xxxxxxxxxxxxxxx > Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx> > Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> Patch applied to wireless-next.git, thanks. 8890b9bca38f wifi: ipw2x00: replace deprecated strncpy with strscpy_pad -- https://patchwork.kernel.org/project/linux-wireless/patch/20231017-strncpy-drivers-net-wireless-intel-ipw2x00-ipw2200-c-v2-1-465e10dc817c@xxxxxxxxxx/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
