From b8bff599261c930630385ee21d3f98e7ce7d4843 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sun, 22 Mar 2020 15:46:24 -0500 Subject: exec: Factor security_bprm_creds_for_exec out of security_bprm_set_creds Today security_bprm_set_creds has several implementations: apparmor_bprm_set_creds, cap_bprm_set_creds, selinux_bprm_set_creds, smack_bprm_set_creds, and tomoyo_bprm_set_creds. Except for cap_bprm_set_creds they all test bprm->called_set_creds and return immediately if it is true. The function cap_bprm_set_creds ignores bprm->calld_sed_creds entirely. Create a new LSM hook security_bprm_creds_for_exec that is called just before prepare_binprm in __do_execve_file, resulting in a LSM hook that is called exactly once for the entire of exec. Modify the bits of security_bprm_set_creds that only want to be called once per exec into security_bprm_creds_for_exec, leaving only cap_bprm_set_creds behind. Remove bprm->called_set_creds all of it's former users have been moved to security_bprm_creds_for_exec. Add or upate comments a appropriate to bring them up to date and to reflect this change. Link: https://lkml.kernel.org/r/87v9kszrzh.fsf_-_@x220.int.ebiederm.org Acked-by: Linus Torvalds Acked-by: Casey Schaufler # For the LSM and Smack bits Reviewed-by: Kees Cook Signed-off-by: "Eric W. Biederman" --- security/apparmor/domain.c | 7 ++----- security/apparmor/include/domain.h | 2 +- security/apparmor/lsm.c | 2 +- 3 files changed, 4 insertions(+), 7 deletions(-) (limited to 'security/apparmor') diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c index 6ceb74e0f789..0b870a647488 100644 --- a/security/apparmor/domain.c +++ b/security/apparmor/domain.c @@ -854,14 +854,14 @@ static struct aa_label *handle_onexec(struct aa_label *label, } /** - * apparmor_bprm_set_creds - set the new creds on the bprm struct + * apparmor_bprm_creds_for_exec - Update the new creds on the bprm struct * @bprm: binprm for the exec (NOT NULL) * * Returns: %0 or error on failure * * TODO: once the other paths are done see if we can't refactor into a fn */ -int apparmor_bprm_set_creds(struct linux_binprm *bprm) +int apparmor_bprm_creds_for_exec(struct linux_binprm *bprm) { struct aa_task_ctx *ctx; struct aa_label *label, *new = NULL; @@ -875,9 +875,6 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm) file_inode(bprm->file)->i_mode }; - if (bprm->called_set_creds) - return 0; - ctx = task_ctx(current); AA_BUG(!cred_label(bprm->cred)); AA_BUG(!ctx); diff --git a/security/apparmor/include/domain.h b/security/apparmor/include/domain.h index 21b875fe2d37..d14928fe1c6f 100644 --- a/security/apparmor/include/domain.h +++ b/security/apparmor/include/domain.h @@ -30,7 +30,7 @@ struct aa_domain { struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, const char **name); -int apparmor_bprm_set_creds(struct linux_binprm *bprm); +int apparmor_bprm_creds_for_exec(struct linux_binprm *bprm); void aa_free_domain_entries(struct aa_domain *domain); int aa_change_hat(const char *hats[], int count, u64 token, int flags); diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index b621ad74f54a..3623ab08279d 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -1232,7 +1232,7 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare), LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer), - LSM_HOOK_INIT(bprm_set_creds, apparmor_bprm_set_creds), + LSM_HOOK_INIT(bprm_creds_for_exec, apparmor_bprm_creds_for_exec), LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds), LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds), -- cgit v1.2.3-59-g8ed1b