diff options
| author | Paul Moore <paul@paul-moore.com> | 2021-09-29 17:01:21 +0200 |
|---|---|---|
| committer | Paul Moore <paul@paul-moore.com> | 2021-11-22 23:52:47 +0100 |
| commit | 6326948f940dc3f77066d5cdc44ba6afe67830c0 (patch) | |
| tree | 13976c9bfaedfc1105ac27a1efaf9c752d3949ee /security/smack | |
| parent | Linux 5.16-rc1 (diff) | |
| download | linux-6326948f940dc3f77066d5cdc44ba6afe67830c0.tar.xz linux-6326948f940dc3f77066d5cdc44ba6afe67830c0.zip | |
lsm: security_task_getsecid_subj() -> security_current_getsecid_subj()
The security_task_getsecid_subj() LSM hook invites misuse by allowing
callers to specify a task even though the hook is only safe when the
current task is referenced. Fix this by removing the task_struct
argument to the hook, requiring LSM implementations to use the
current task. While we are changing the hook declaration we also
rename the function to security_current_getsecid_subj() in an effort
to reinforce that the hook captures the subjective credentials of the
current task and not an arbitrary task on the system.
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Diffstat (limited to 'security/smack')
| -rw-r--r-- | security/smack/smack.h | 16 | ||||
| -rw-r--r-- | security/smack/smack_lsm.c | 9 |
2 files changed, 4 insertions, 21 deletions
diff --git a/security/smack/smack.h b/security/smack/smack.h index 99c3422596ab..fc837dcebf96 100644 --- a/security/smack/smack.h +++ b/security/smack/smack.h @@ -389,22 +389,6 @@ static inline struct smack_known *smk_of_task(const struct task_smack *tsp) return tsp->smk_task; } -static inline struct smack_known *smk_of_task_struct_subj( - const struct task_struct *t) -{ - struct smack_known *skp; - const struct cred *cred; - - rcu_read_lock(); - - cred = rcu_dereference(t->cred); - skp = smk_of_task(smack_cred(cred)); - - rcu_read_unlock(); - - return skp; -} - static inline struct smack_known *smk_of_task_struct_obj( const struct task_struct *t) { diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index efd35b07c7f8..14b279cc75c9 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -2067,15 +2067,14 @@ static int smack_task_getsid(struct task_struct *p) } /** - * smack_task_getsecid_subj - get the subjective secid of the task - * @p: the task + * smack_current_getsecid_subj - get the subjective secid of the current task * @secid: where to put the result * * Sets the secid to contain a u32 version of the task's subjective smack label. */ -static void smack_task_getsecid_subj(struct task_struct *p, u32 *secid) +static void smack_current_getsecid_subj(u32 *secid) { - struct smack_known *skp = smk_of_task_struct_subj(p); + struct smack_known *skp = smk_of_current(); *secid = skp->smk_secid; } @@ -4807,7 +4806,7 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(task_setpgid, smack_task_setpgid), LSM_HOOK_INIT(task_getpgid, smack_task_getpgid), LSM_HOOK_INIT(task_getsid, smack_task_getsid), - LSM_HOOK_INIT(task_getsecid_subj, smack_task_getsecid_subj), + LSM_HOOK_INIT(current_getsecid_subj, smack_current_getsecid_subj), LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid_obj), LSM_HOOK_INIT(task_setnice, smack_task_setnice), LSM_HOOK_INIT(task_setioprio, smack_task_setioprio), |