Messages in this thread | | | From | Justin Stitt <> | Date | Sat, 30 Sep 2023 10:08:34 +0900 | Subject | Re: drivers/md/dm-cache-metadata.c:1705:9: warning: 'strncpy' specified bound 16 equals destination size |
| |
On Sat, Sep 30, 2023 at 2:49 AM Kees Cook <keescook@chromium.org> wrote: > > On Thu, Sep 28, 2023 at 11:36:46AM +0200, Miguel Ojeda wrote: > > On Thu, Sep 28, 2023 at 12:24 AM kernel test robot <lkp@intel.com> wrote: > > > > > > In function 'write_hints', > > > inlined from 'dm_cache_write_hints' at drivers/md/dm-cache-metadata.c:1729:6: > > > >> drivers/md/dm-cache-metadata.c:1705:9: warning: 'strncpy' specified bound 16 equals destination size [-Wstringop-truncation] > > > 1705 | strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name)); > > > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > > This looks fine given the check above it. In any case, since it > > appears the code wants to terminate the string, this should use > > `strscpy*()`, right? > > I agree. I can't tell if _pad is needed though. I think struct > dm_cache_metadata is only used internally? And I see at least the > initial allocation is zeroed: > > cmd = kzalloc(sizeof(*cmd), GFP_KERNEL); > > Regardless, for background, > > struct has: > char policy_name[CACHE_POLICY_NAME_SIZE]; > > code does: > const char *policy_name = dm_cache_policy_get_name(policy); > > if (!policy_name[0] || > (strlen(policy_name) > sizeof(cmd->policy_name) - 1)) > return -EINVAL; > > strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name)); > > > Justin, can you add this to your queue (if it's not already there)?
I sent a patch out earlier this week [1].
The line # on the diff v.s the warning is off though. I suspect I may need a rebase if it doesn't apply clean.
> > -Kees > > -- > Kees Cook
[1]: https://lore.kernel.org/all/20230925-strncpy-drivers-md-dm-cache-metadata-c-v1-1-4b75c7db0cfe@google.com/
| |