Re: [PATCH v3] security: commoncap: drop stale CAP_FS_MASK FIXME

["Serge E. Hallyn" <serge@hallyn.com>]

On Mon, Oct 26, 2026 at 10:10:10AM -0300, Adriano Cordova wrote:
> CAP_FS_SET is exactly the set of capabilities that an fsuid of 0
> historically granted (see CAP_FS_MASK in include/linux/capability.h),
> so cap_task_fix_setuid() drops that set from the effective set when
> fsuid leaves 0.  Remove the stale FIXME.
> 
> Signed-off-by: Adriano Cordova <adrianox@gmail.com>

Thanks.  Will add this to caps-next for next merge.

Reviewed-by: Serge Hallyn <serge@hallyn.com>

> ---
> v3: just drop the FIXME instead of replacing it with another explanation.
> 
>  security/commoncap.c | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/security/commoncap.c b/security/commoncap.c
> index 3399535808fe..484d2b9256e9 100644
> --- a/security/commoncap.c
> +++ b/security/commoncap.c
> @@ -1171,9 +1171,6 @@ int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags)
>  	case LSM_SETID_FS:
>  		/* juggle the capabilities to follow FSUID changes, unless
>  		 * otherwise suppressed
> -		 *
> -		 * FIXME - is fsuser used for all CAP_FS_MASK capabilities?
> -		 *          if not, we might be a bit too harsh here.
>  		 */
>  		if (!issecure(SECURE_NO_SETUID_FIXUP)) {
>  			kuid_t root_uid = make_kuid(old->user_ns, 0);
> -- 
> 2.51.0