From ddb4a1442def2a78b91a85b4251fb712ef23662b Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 18 Jul 2017 15:25:23 -0700 Subject: exec: Rename bprm->cred_prepared to called_set_creds 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 Cc: Stephen Smalley Cc: Casey Schaufler Signed-off-by: Kees Cook Acked-by: John Johansen Acked-by: James Morris Acked-by: Paul Moore Acked-by: Serge Hallyn --- security/smack/smack_lsm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'security/smack') diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 463af86812c7..db8e16ec223b 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; -- cgit v1.2.3 From ccbb6e1065fa9cd27f2bf406e8c5d5cf0273f554 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 18 Jul 2017 15:25:26 -0700 Subject: smack: Refactor to remove bprm_secureexec hook The Smack bprm_secureexec hook can be merged with the bprm_set_creds hook since it's dealing with the same information, and all of the details are finalized during the first call to the bprm_set_creds hook via prepare_binprm() (subsequent calls due to binfmt_script, etc, are ignored via bprm->called_set_creds). Here, the test can just happen at the end of the bprm_set_creds hook, and the bprm_secureexec hook can be dropped. Signed-off-by: Kees Cook Acked-by: Serge Hallyn Reviewed-by: James Morris Reviewed-by: Casey Schaufler --- security/smack/smack_lsm.c | 21 ++++----------------- 1 file changed, 4 insertions(+), 17 deletions(-) (limited to 'security/smack') diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index db8e16ec223b..791d028207b9 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -950,6 +950,10 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm) bsp->smk_task = isp->smk_task; bprm->per_clear |= PER_CLEAR_ON_SETID; + /* Decide if this is a secure exec. */ + if (bsp->smk_task != bsp->smk_forked) + bprm->secureexec = 1; + return 0; } @@ -967,22 +971,6 @@ static void smack_bprm_committing_creds(struct linux_binprm *bprm) current->pdeath_signal = 0; } -/** - * smack_bprm_secureexec - Return the decision to use secureexec. - * @bprm: binprm for exec - * - * Returns 0 on success. - */ -static int smack_bprm_secureexec(struct linux_binprm *bprm) -{ - struct task_smack *tsp = current_security(); - - if (tsp->smk_task != tsp->smk_forked) - return 1; - - return 0; -} - /* * Inode hooks */ @@ -4646,7 +4634,6 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(bprm_set_creds, smack_bprm_set_creds), LSM_HOOK_INIT(bprm_committing_creds, smack_bprm_committing_creds), - LSM_HOOK_INIT(bprm_secureexec, smack_bprm_secureexec), LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security), LSM_HOOK_INIT(inode_free_security, smack_inode_free_security), -- cgit v1.2.3 From 35b372b76f7153142cd4838ef1e1e094d115f46f Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 18 Jul 2017 15:25:33 -0700 Subject: smack: Remove redundant pdeath_signal clearing This removes the redundant pdeath_signal clearing in Smack: the check in smack_bprm_committing_creds() matches the check in smack_bprm_set_creds() (which used to be in the now-removed smack_bprm_securexec() hook) and since secureexec is now being checked for clearing pdeath_signal, this is redundant to the common exec code. Signed-off-by: Kees Cook Acked-by: Serge Hallyn Reviewed-by: James Morris Reviewed-by: Casey Schaufler --- security/smack/smack_lsm.c | 15 --------------- 1 file changed, 15 deletions(-) (limited to 'security/smack') diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 791d028207b9..319add31b4a4 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -957,20 +957,6 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm) return 0; } -/** - * smack_bprm_committing_creds - Prepare to install the new credentials - * from bprm. - * - * @bprm: binprm for exec - */ -static void smack_bprm_committing_creds(struct linux_binprm *bprm) -{ - struct task_smack *bsp = bprm->cred->security; - - if (bsp->smk_task != bsp->smk_forked) - current->pdeath_signal = 0; -} - /* * Inode hooks */ @@ -4633,7 +4619,6 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(sb_parse_opts_str, smack_parse_opts_str), LSM_HOOK_INIT(bprm_set_creds, smack_bprm_set_creds), - LSM_HOOK_INIT(bprm_committing_creds, smack_bprm_committing_creds), LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security), LSM_HOOK_INIT(inode_free_security, smack_inode_free_security), -- cgit v1.2.3