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SubjectRe: [PATCH 5/6] file capabilities: remove needless inline functions
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Serge,

I'd much rather simply remove the target argument from the
security_capset_check() call. Relying on the caller to not do something
bad seems fragile... If the code internally operates on current only,
then it doesn't need a target argument... No? (Evidently, such a change
is also needed to selinux_capset_check() too, but this doesn't look like
it will pose a problem for the selinux code.)

Cheers

Andrew

Serge E. Hallyn wrote:
> cap_limit_ptraced_target always returns 1, so nix it.
>
> cap_block_setpcap can't return 1 any more, because
> kernel/capabilities.c:sys_capset() will return -EPERM
> if it is called on a task other than current, and will
> never get to cap_capset_check.
>
> This brings the vmlinux size with my config down another
> 16 bytes (making up for the 8 byte increase from the
> last patch).
>
> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
> ---
> security/commoncap.c | 22 +++-------------------
> 1 files changed, 3 insertions(+), 19 deletions(-)
>
> diff --git a/security/commoncap.c b/security/commoncap.c
> index d48fdd8..e5afb7c 100644
> --- a/security/commoncap.c
> +++ b/security/commoncap.c
> @@ -93,15 +93,6 @@ int cap_capget (struct task_struct *target, kernel_cap_t *effective,
> return 0;
> }
>
> -static inline int cap_block_setpcap(struct task_struct *target)
> -{
> - /*
> - * No support for remote process capability manipulation with
> - * filesystem capability support.
> - */
> - return (target != current);
> -}
> -
> static inline int cap_inh_is_capped(void)
> {
> /*
> @@ -112,14 +103,9 @@ static inline int cap_inh_is_capped(void)
> return (cap_capable(current, CAP_SETPCAP) != 0);
> }
>
> -static inline int cap_limit_ptraced_target(void) { return 1; }
> -
> int cap_capset_check (struct task_struct *target, kernel_cap_t *effective,
> kernel_cap_t *inheritable, kernel_cap_t *permitted)
> {
> - if (cap_block_setpcap(target)) {
> - return -EPERM;
> - }
> if (cap_inh_is_capped()
> && !cap_issubset(*inheritable,
> cap_combine(target->cap_inheritable,
> @@ -343,11 +329,9 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe)
> bprm->e_uid = current->uid;
> bprm->e_gid = current->gid;
> }
> - if (cap_limit_ptraced_target()) {
> - bprm->cap_post_exec_permitted = cap_intersect(
> - bprm->cap_post_exec_permitted,
> - current->cap_permitted);
> - }
> + bprm->cap_post_exec_permitted = cap_intersect(
> + bprm->cap_post_exec_permitted,
> + current->cap_permitted);
> }
> }
>
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