On 07/18/2017 03:25 PM, Kees Cook wrote:
> The cred_prepared bprm flag has a misleading name. It has nothing to do
> with the bprm_prepare_cred hook, and actually tracks if bprm_set_creds has
> been called. Rename this flag and improve its comment.
>
> Cc: David Howells <dhowells@xxxxxxxxxx>
> Cc: John Johansen <john.johansen@xxxxxxxxxxxxx>
> Cc: Paul Moore <paul@xxxxxxxxxxxxxx>
> Cc: Stephen Smalley <sds@xxxxxxxxxxxxx>
> Cc: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
> Cc: James Morris <james.l.morris@xxxxxxxxxx>
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
looks good
Acked-by: John Johansen <john.johansen@xxxxxxxxxxxxx>
> ---
> fs/binfmt_flat.c | 2 +-
> fs/exec.c | 2 +-
> include/linux/binfmts.h | 8 ++++++--
> security/apparmor/domain.c | 2 +-
> security/selinux/hooks.c | 2 +-
> security/smack/smack_lsm.c | 2 +-
> security/tomoyo/tomoyo.c | 2 +-
> 7 files changed, 12 insertions(+), 8 deletions(-)
>
> diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
> index 2edcefc0a294..a722530cc468 100644
> --- a/fs/binfmt_flat.c
> +++ b/fs/binfmt_flat.c
> @@ -885,7 +885,7 @@ static int load_flat_shared_library(int id, struct lib_info *libs)
> * as we're past the point of no return and are dealing with shared
> * libraries.
> */
> - bprm.cred_prepared = 1;
> + bprm.called_set_creds = 1;
>
> res = prepare_binprm(&bprm);
>
> diff --git a/fs/exec.c b/fs/exec.c
> index 904199086490..925c85a45d97 100644
> --- a/fs/exec.c
> +++ b/fs/exec.c
> @@ -1547,7 +1547,7 @@ int prepare_binprm(struct linux_binprm *bprm)
> retval = security_bprm_set_creds(bprm);
> if (retval)
> return retval;
> - bprm->cred_prepared = 1;
> + bprm->called_set_creds = 1;
>
> memset(bprm->buf, 0, BINPRM_BUF_SIZE);
> return kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE);
> diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
> index 9508b5f83c7e..36be5a67517a 100644
> --- a/include/linux/binfmts.h
> +++ b/include/linux/binfmts.h
> @@ -25,8 +25,12 @@ struct linux_binprm {
> struct mm_struct *mm;
> unsigned long p; /* current top of mem */
> unsigned int
> - cred_prepared:1,/* true if creds already prepared (multiple
> - * preps happen for interpreters) */
> + /*
> + * True after the bprm_set_creds hook has been called once
> + * (multiple calls can be made via prepare_binprm() for
> + * binfmt_script/misc).
> + */
> + called_set_creds:1,
> cap_effective:1,/* true if has elevated effective capabilities,
> * false if not; except for init which inherits
> * its parent's caps anyway */
> diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
> index 001e133a3c8c..878407e023e3 100644
> --- a/security/apparmor/domain.c
> +++ b/security/apparmor/domain.c
> @@ -350,7 +350,7 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
> const char *name = NULL, *info = NULL;
> int error = 0;
>
> - if (bprm->cred_prepared)
> + if (bprm->called_set_creds)
> return 0;
>
> ctx = cred_ctx(bprm->cred);
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 819fd6858b49..0f1450a06b02 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -2327,7 +2327,7 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm)
>
> /* SELinux context only depends on initial program or script and not
> * the script interpreter */
> - if (bprm->cred_prepared)
> + if (bprm->called_set_creds)
> return 0;
>
> old_tsec = current_security();
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 658f5d8c7e76..7d4b2e221124 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -917,7 +917,7 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm)
> struct superblock_smack *sbsp;
> int rc;
>
> - if (bprm->cred_prepared)
> + if (bprm->called_set_creds)
> return 0;
>
> isp = inode->i_security;
> diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c
> index 130b4fa4f65f..d25b705360e0 100644
> --- a/security/tomoyo/tomoyo.c
> +++ b/security/tomoyo/tomoyo.c
> @@ -76,7 +76,7 @@ static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
> * Do only if this function is called for the first time of an execve
> * operation.
> */
> - if (bprm->cred_prepared)
> + if (bprm->called_set_creds)
> return 0;
> #ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
> /*
>
