From 86b92cb782b38d71ee344af20fcbe5106dd19dbe Mon Sep 17 00:00:00 2001 From: John Johansen Date: Fri, 9 Jun 2017 14:15:20 -0700 Subject: [PATCH] apparmor: move resource checks to using labels Signed-off-by: John Johansen --- security/apparmor/include/resource.h | 4 +- security/apparmor/lsm.c | 6 +- security/apparmor/resource.c | 112 ++++++++++++++++++--------- 3 files changed, 80 insertions(+), 42 deletions(-) diff --git a/security/apparmor/include/resource.h b/security/apparmor/include/resource.h index f6289f335c4d..76f1586c9adb 100644 --- a/security/apparmor/include/resource.h +++ b/security/apparmor/include/resource.h @@ -37,10 +37,10 @@ struct aa_rlimit { extern struct aa_sfs_entry aa_sfs_entry_rlimit[]; int aa_map_resource(int resource); -int aa_task_setrlimit(struct aa_profile *profile, struct task_struct *, +int aa_task_setrlimit(struct aa_label *label, struct task_struct *task, unsigned int resource, struct rlimit *new_rlim); -void __aa_transition_rlimits(struct aa_profile *old, struct aa_profile *new); +void __aa_transition_rlimits(struct aa_label *old, struct aa_label *new); static inline void aa_free_rlimit_rules(struct aa_rlimit *rlims) { diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index bcfdcdb3eae2..c3e98f74268f 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -625,8 +625,7 @@ static void apparmor_bprm_committing_creds(struct linux_binprm *bprm) current->pdeath_signal = 0; /* reset soft limits and set hard limits for the new label */ - __aa_transition_rlimits(labels_profile(label), - labels_profile(new_ctx->label)); + __aa_transition_rlimits(label, new_ctx->label); } /** @@ -646,8 +645,7 @@ static int apparmor_task_setrlimit(struct task_struct *task, int error = 0; if (!unconfined(label)) - error = aa_task_setrlimit(labels_profile(label), task, - resource, new_rlim); + error = aa_task_setrlimit(label, task, resource, new_rlim); __end_current_label_crit_section(label); return error; diff --git a/security/apparmor/resource.c b/security/apparmor/resource.c index 2474ee0b3467..d8bc842594ed 100644 --- a/security/apparmor/resource.c +++ b/security/apparmor/resource.c @@ -13,6 +13,7 @@ */ #include +#include #include "include/audit.h" #include "include/context.h" @@ -36,6 +37,11 @@ static void audit_cb(struct audit_buffer *ab, void *va) audit_log_format(ab, " rlimit=%s value=%lu", rlim_names[aad(sa)->rlim.rlim], aad(sa)->rlim.max); + if (aad(sa)->peer) { + audit_log_format(ab, " peer="); + aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer, + FLAGS_NONE, GFP_ATOMIC); + } } /** @@ -48,13 +54,17 @@ static void audit_cb(struct audit_buffer *ab, void *va) * Returns: 0 or sa->error else other error code on failure */ static int audit_resource(struct aa_profile *profile, unsigned int resource, - unsigned long value, int error) + unsigned long value, struct aa_label *peer, + const char *info, int error) { DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SETRLIMIT); aad(&sa)->rlim.rlim = resource; aad(&sa)->rlim.max = value; + aad(&sa)->peer = peer; + aad(&sa)->info = info; aad(&sa)->error = error; + return aa_audit(AUDIT_APPARMOR_AUTO, profile, &sa, audit_cb); } @@ -72,9 +82,21 @@ int aa_map_resource(int resource) return rlim_map[resource]; } +static int profile_setrlimit(struct aa_profile *profile, unsigned int resource, + struct rlimit *new_rlim) +{ + int e = 0; + + if (profile->rlimits.mask & (1 << resource) && new_rlim->rlim_max > + profile->rlimits.limits[resource].rlim_max) + e = -EACCES; + return audit_resource(profile, resource, new_rlim->rlim_max, NULL, NULL, + e); +} + /** * aa_task_setrlimit - test permission to set an rlimit - * @profile - profile confining the task (NOT NULL) + * @label - label confining the task (NOT NULL) * @task - task the resource is being set on * @resource - the resource being set * @new_rlim - the new resource limit (NOT NULL) @@ -83,14 +105,15 @@ int aa_map_resource(int resource) * * Returns: 0 or error code if setting resource failed */ -int aa_task_setrlimit(struct aa_profile *profile, struct task_struct *task, +int aa_task_setrlimit(struct aa_label *label, struct task_struct *task, unsigned int resource, struct rlimit *new_rlim) { - struct aa_label *task_label; + struct aa_profile *profile; + struct aa_label *peer; int error = 0; rcu_read_lock(); - task_label = aa_get_newest_cred_label((__task_cred(task))); + peer = aa_get_newest_cred_label(__task_cred(task)); rcu_read_unlock(); /* TODO: extend resource control to handle other (non current) @@ -99,53 +122,70 @@ int aa_task_setrlimit(struct aa_profile *profile, struct task_struct *task, * the same profile or that the task setting the resource of another * task has CAP_SYS_RESOURCE. */ - if ((profile != labels_profile(task_label) && - 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; - aa_put_label(task_label); - - return audit_resource(profile, resource, new_rlim->rlim_max, error); + if (label != peer && + !aa_capable(label, CAP_SYS_RESOURCE, SECURITY_CAP_NOAUDIT)) + error = fn_for_each(label, profile, + audit_resource(profile, resource, + new_rlim->rlim_max, peer, + "cap_sys_resoure", -EACCES)); + else + error = fn_for_each_confined(label, profile, + profile_setrlimit(profile, resource, new_rlim)); + aa_put_label(peer); + + return error; } /** * __aa_transition_rlimits - apply new profile rlimits - * @old: old profile on task (NOT NULL) - * @new: new profile with rlimits to apply (NOT NULL) + * @old_l: old label on task (NOT NULL) + * @new_l: new label with rlimits to apply (NOT NULL) */ -void __aa_transition_rlimits(struct aa_profile *old, struct aa_profile *new) +void __aa_transition_rlimits(struct aa_label *old_l, struct aa_label *new_l) { unsigned int mask = 0; struct rlimit *rlim, *initrlim; - int i; + struct aa_profile *old, *new; + struct label_it i; + + old = labels_profile(old_l); + new = labels_profile(new_l); - /* for any rlimits the profile controlled reset the soft limit - * to the less of the tasks hard limit and the init tasks soft limit + /* for any rlimits the profile controlled, reset the soft limit + * to the lesser of the tasks hard limit and the init tasks soft limit */ - if (old->rlimits.mask) { - for (i = 0, mask = 1; i < RLIM_NLIMITS; i++, mask <<= 1) { - if (old->rlimits.mask & mask) { - rlim = current->signal->rlim + i; - initrlim = init_task.signal->rlim + i; - rlim->rlim_cur = min(rlim->rlim_max, - initrlim->rlim_cur); + label_for_each_confined(i, old_l, old) { + if (old->rlimits.mask) { + int j; + + for (j = 0, mask = 1; j < RLIM_NLIMITS; j++, + mask <<= 1) { + if (old->rlimits.mask & mask) { + rlim = current->signal->rlim + j; + initrlim = init_task.signal->rlim + j; + rlim->rlim_cur = min(rlim->rlim_max, + initrlim->rlim_cur); + } } } } /* set any new hard limits as dictated by the new profile */ - if (!new->rlimits.mask) - return; - for (i = 0, mask = 1; i < RLIM_NLIMITS; i++, mask <<= 1) { - if (!(new->rlimits.mask & mask)) - continue; + label_for_each_confined(i, new_l, new) { + int j; - rlim = current->signal->rlim + i; - rlim->rlim_max = min(rlim->rlim_max, - new->rlimits.limits[i].rlim_max); - /* soft limit should not exceed hard limit */ - rlim->rlim_cur = min(rlim->rlim_cur, rlim->rlim_max); + if (!new->rlimits.mask) + continue; + for (j = 0, mask = 1; j < RLIM_NLIMITS; j++, mask <<= 1) { + if (!(new->rlimits.mask & mask)) + continue; + + rlim = current->signal->rlim + j; + rlim->rlim_max = min(rlim->rlim_max, + new->rlimits.limits[j].rlim_max); + /* soft limit should not exceed hard limit */ + rlim->rlim_cur = min(rlim->rlim_cur, rlim->rlim_max); + } } } -- 2.20.1