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| author | Paul Moore <paul@paul-moore.com> | 2021-09-29 11:01:21 -0400 |
|---|---|---|
| committer | Paul Moore <paul@paul-moore.com> | 2021-11-22 17:52:47 -0500 |
| commit | 6326948f940dc3f77066d5cdc44ba6afe67830c0 (patch) | |
| tree | 13976c9bfaedfc1105ac27a1efaf9c752d3949ee /kernel | |
| parent | fa55b7dcdc43c1aa1ba12bca9d2dd4318c2a0dbf (diff) | |
| download | lwn-6326948f940dc3f77066d5cdc44ba6afe67830c0.tar.gz lwn-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 'kernel')
| -rw-r--r-- | kernel/audit.c | 4 | ||||
| -rw-r--r-- | kernel/auditfilter.c | 3 | ||||
| -rw-r--r-- | kernel/auditsc.c | 11 |
3 files changed, 13 insertions, 5 deletions
diff --git a/kernel/audit.c b/kernel/audit.c index 121d37e700a6..d4084751cfe6 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -2132,7 +2132,7 @@ int audit_log_task_context(struct audit_buffer *ab) int error; u32 sid; - security_task_getsecid_subj(current, &sid); + security_current_getsecid_subj(&sid); if (!sid) return 0; @@ -2353,7 +2353,7 @@ int audit_signal_info(int sig, struct task_struct *t) audit_sig_uid = auid; else audit_sig_uid = uid; - security_task_getsecid_subj(current, &audit_sig_sid); + security_current_getsecid_subj(&audit_sig_sid); } return audit_signal_info_syscall(t); diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index d75acb014ccd..4173e771650c 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -1368,8 +1368,7 @@ int audit_filter(int msgtype, unsigned int listtype) case AUDIT_SUBJ_SEN: case AUDIT_SUBJ_CLR: if (f->lsm_rule) { - security_task_getsecid_subj(current, - &sid); + security_current_getsecid_subj(&sid); result = security_audit_rule_match(sid, f->type, f->op, f->lsm_rule); } diff --git a/kernel/auditsc.c b/kernel/auditsc.c index b517947bfa48..fce5d43a933f 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -666,7 +666,16 @@ static int audit_filter_rules(struct task_struct *tsk, logged upon error */ if (f->lsm_rule) { if (need_sid) { - security_task_getsecid_subj(tsk, &sid); + /* @tsk should always be equal to + * @current with the exception of + * fork()/copy_process() in which case + * the new @tsk creds are still a dup + * of @current's creds so we can still + * use security_current_getsecid_subj() + * here even though it always refs + * @current's creds + */ + security_current_getsecid_subj(&sid); need_sid = 0; } result = security_audit_rule_match(sid, f->type, |