Re: [PATCH v3 05/15] smack: Refactor to remove bprm_secureexec hook
From: Kees Cook <hidden>
Date: 2017-07-26 03:58:01
Also in:
linux-fsdevel, linux-security-module
On Tue, Jul 18, 2017 at 3:25 PM, Kees Cook [off-list ref] wrote:
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. Cc: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Kees Cook <redacted>
How does this look to you, Casey? I've only got a few unreviewed patches in this series. Two touch Smack. :) Thanks! -Kees
quoted hunk ↗ jump to hunk
--- security/smack/smack_lsm.c | 21 ++++----------------- 1 file changed, 4 insertions(+), 17 deletions(-)diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 7d4b2e221124..4f1967be3d20 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), --2.7.4
-- Kees Cook Pixel Security