On Tue, 12 Dec 2023 13:47:42 -0800, Kees Cook wrote:
> Since "dev_search_path" can technically be as large as PATH_MAX,
> there was a risk of truncation when copying it and a second string
> into "full_path" since it was also PATH_MAX sized. The W=1 builds were
> reporting this warning:
>
> drivers/block/rnbd/rnbd-srv.c: In function 'process_msg_open.isra':
> drivers/block/rnbd/rnbd-srv.c:616:51: warning: '%s' directive output may be truncated writing up to 254 bytes into a region of size between 0 and 4095 [-Wformat-truncation=]
> 616 | snprintf(full_path, PATH_MAX, "%s/%s",
> | ^~
> In function 'rnbd_srv_get_full_path',
> inlined from 'process_msg_open.isra' at drivers/block/rnbd/rnbd-srv.c:721:14: drivers/block/rnbd/rnbd-srv.c:616:17: note: 'snprintf' output between 2 and 4351 bytes into a destination of size 4096
> 616 | snprintf(full_path, PATH_MAX, "%s/%s",
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 617 | dev_search_path, dev_name);
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> [...]
Applied, thanks!
[1/1] block/rnbd-srv: Check for unlikely string overflow
commit: 9e4bf6a08d1e127bcc4bd72557f2dfafc6bc7f41
Best regards,
--
Jens Axboe
