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apparmor: move capability checks to using labels

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Signed-off-by: John Johansen <john.johansen@canonical.com>
This commit is contained in:
John Johansen 2017-06-09 14:07:02 -07:00
parent 317d9a054e
commit c70c86c421
5 changed files with 58 additions and 29 deletions
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57
security/apparmor/capability.c
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@ -48,15 +48,16 @@ static DEFINE_PER_CPU(struct audit_cache, audit_cache);
static void audit_cb(struct audit_buffer *ab, void *va)
{
struct common_audit_data *sa = va;
audit_log_format(ab, " capname=");
audit_log_untrustedstring(ab, capability_names[sa->u.cap]);
}
/**
* audit_caps - audit a capability
* @sa: audit data
* @profile: profile being tested for confinement (NOT NULL)
* @cap: capability tested
@audit: whether an audit record should be generated
* @error: error code returned by test
*
* Do auditing of capability and handle, audit/complain/kill modes switching
@ -64,16 +65,13 @@ static void audit_cb(struct audit_buffer *ab, void *va)
*
* Returns: 0 or sa->error on success, error code on failure
*/
static int audit_caps(struct aa_profile *profile, int cap, int audit,
int error)
static int audit_caps(struct common_audit_data *sa, struct aa_profile *profile,
int cap, int error)
{
struct audit_cache *ent;
int type = AUDIT_APPARMOR_AUTO;
DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_CAP, OP_CAPABLE);
sa.u.cap = cap;
aad(&sa)->error = error;
if (audit == SECURITY_CAP_NOAUDIT)
aad(&sa)->info = "optional: no audit";
aad(sa)->error = error;
if (likely(!error)) {
/* test if auditing is being forced */
@ -105,24 +103,44 @@ static int audit_caps(struct aa_profile *profile, int cap, int audit,
}
put_cpu_var(audit_cache);
return aa_audit(type, profile, &sa, audit_cb);
return aa_audit(type, profile, sa, audit_cb);
}
/**
* profile_capable - test if profile allows use of capability @cap
* @profile: profile being enforced (NOT NULL, NOT unconfined)
* @cap: capability to test if allowed
* @audit: whether an audit record should be generated
* @sa: audit data (MAY BE NULL indicating no auditing)
*
* Returns: 0 if allowed else -EPERM
*/
static int profile_capable(struct aa_profile *profile, int cap)
static int profile_capable(struct aa_profile *profile, int cap, int audit,
struct common_audit_data *sa)
{
return cap_raised(profile->caps.allow, cap) ? 0 : -EPERM;
int error;
if (cap_raised(profile->caps.allow, cap) &&
!cap_raised(profile->caps.denied, cap))
error = 0;
else
error = -EPERM;
if (audit == SECURITY_CAP_NOAUDIT) {
if (!COMPLAIN_MODE(profile))
return error;
/* audit the cap request in complain mode but note that it
* should be optional.
*/
aad(sa)->info = "optional: no audit";
}
return audit_caps(sa, profile, cap, error);
}
/**
* aa_capable - test permission to use capability
* @profile: profile being tested against (NOT NULL)
* @label: label being tested for capability (NOT NULL)
* @cap: capability to be tested
* @audit: whether an audit record should be generated
*
@ -130,14 +148,15 @@ static int profile_capable(struct aa_profile *profile, int cap)
*
* Returns: 0 on success, or else an error code.
*/
int aa_capable(struct aa_profile *profile, int cap, int audit)
int aa_capable(struct aa_label *label, int cap, int audit)
{
int error = profile_capable(profile, cap);
struct aa_profile *profile;
int error = 0;
DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_CAP, OP_CAPABLE);
if (audit == SECURITY_CAP_NOAUDIT) {
if (!COMPLAIN_MODE(profile))
return error;
}
sa.u.cap = cap;
error = fn_for_each_confined(label, profile,
profile_capable(profile, cap, audit, &sa));
return audit_caps(profile, cap, audit, error);
return error;
}

6
security/apparmor/include/capability.h
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@ -19,11 +19,12 @@
#include "apparmorfs.h"
struct aa_profile;
struct aa_label;
/* aa_caps - confinement data for capabilities
* @allowed: capabilities mask
* @audit: caps that are to be audited
* @denied: caps that are explicitly denied
* @quiet: caps that should not be audited
* @kill: caps that when requested will result in the task being killed
* @extended: caps that are subject finer grained mediation
@ -31,6 +32,7 @@ struct aa_profile;
struct aa_caps {
kernel_cap_t allow;
kernel_cap_t audit;
kernel_cap_t denied;
kernel_cap_t quiet;
kernel_cap_t kill;
kernel_cap_t extended;
@ -38,7 +40,7 @@ struct aa_caps {
extern struct aa_sfs_entry aa_sfs_entry_caps[];
int aa_capable(struct aa_profile *profile, int cap, int audit);
int aa_capable(struct aa_label *label, int cap, int audit);
static inline void aa_free_cap_rules(struct aa_caps *caps)
{

2
security/apparmor/ipc.c
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@ -68,7 +68,7 @@ int aa_may_ptrace(struct aa_profile *tracer, struct aa_profile *tracee,
if (profile_unconfined(tracer) || tracer == tracee)
return 0;
/* log this capability request */
return aa_capable(tracer, CAP_SYS_PTRACE, 1);
return aa_capable(&tracer->label, CAP_SYS_PTRACE, 1);
}
/**

20
security/apparmor/lsm.c
View File

@ -117,20 +117,28 @@ static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
kernel_cap_t *inheritable, kernel_cap_t *permitted)
{
struct aa_label *label;
struct aa_profile *profile;
const struct cred *cred;
rcu_read_lock();
cred = __task_cred(target);
label = aa_get_newest_cred_label(cred);
profile = labels_profile(label);
/*
* cap_capget is stacked ahead of this and will
* initialize effective and permitted.
*/
if (!profile_unconfined(profile) && !COMPLAIN_MODE(profile)) {
*effective = cap_intersect(*effective, profile->caps.allow);
*permitted = cap_intersect(*permitted, profile->caps.allow);
if (!unconfined(label)) {
struct aa_profile *profile;
struct label_it i;
label_for_each_confined(i, label, profile) {
if (COMPLAIN_MODE(profile))
continue;
*effective = cap_intersect(*effective,
profile->caps.allow);
*permitted = cap_intersect(*permitted,
profile->caps.allow);
}
}
rcu_read_unlock();
aa_put_label(label);
@ -146,7 +154,7 @@ static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
label = aa_get_newest_cred_label(cred);
if (!unconfined(label))
error = aa_capable(labels_profile(label), cap, audit);
error = aa_capable(label, cap, audit);
aa_put_label(label);
return error;

2
security/apparmor/resource.c
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@ -100,7 +100,7 @@ int aa_task_setrlimit(struct aa_profile *profile, struct task_struct *task,
* task has CAP_SYS_RESOURCE.
*/
if ((profile != labels_profile(task_label) &&
aa_capable(profile, CAP_SYS_RESOURCE, 1)) ||
aa_capable(&profile->label, CAP_SYS_RESOURCE, 1)) ||
(profile->rlimits.mask & (1 << resource) &&
new_rlim->rlim_max > profile->rlimits.limits[resource].rlim_max))
error = -EACCES;