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Diffstat (limited to '')
| -rw-r--r-- | security/apparmor/capability.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/security/apparmor/capability.c b/security/apparmor/capability.c new file mode 100644 index 000000000..deccea865 --- /dev/null +++ b/security/apparmor/capability.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor capability mediation functions + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#include <linux/capability.h> +#include <linux/errno.h> +#include <linux/gfp.h> +#include <linux/security.h> + +#include "include/apparmor.h" +#include "include/capability.h" +#include "include/cred.h" +#include "include/policy.h" +#include "include/audit.h" + +/* + * Table of capability names: we generate it from capabilities.h. + */ +#include "capability_names.h" + +struct aa_sfs_entry aa_sfs_entry_caps[] = { + AA_SFS_FILE_STRING("mask", AA_SFS_CAPS_MASK), + { } +}; + +struct audit_cache { + struct aa_profile *profile; + kernel_cap_t caps; +}; + +static DEFINE_PER_CPU(struct audit_cache, audit_cache); + +/** + * audit_cb - call back for capability components of audit struct + * @ab - audit buffer (NOT NULL) + * @va - audit struct to audit data from (NOT NULL) + */ +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 + * @error: error code returned by test + * + * Do auditing of capability and handle, audit/complain/kill modes switching + * and duplicate message elimination. + * + * Returns: 0 or sa->error on success, error code on failure + */ +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; + + aad(sa)->error = error; + + if (likely(!error)) { + /* test if auditing is being forced */ + if (likely((AUDIT_MODE(profile) != AUDIT_ALL) && + !cap_raised(profile->caps.audit, cap))) + return 0; + type = AUDIT_APPARMOR_AUDIT; + } else if (KILL_MODE(profile) || + cap_raised(profile->caps.kill, cap)) { + type = AUDIT_APPARMOR_KILL; + } else if (cap_raised(profile->caps.quiet, cap) && + AUDIT_MODE(profile) != AUDIT_NOQUIET && + AUDIT_MODE(profile) != AUDIT_ALL) { + /* quiet auditing */ + return error; + } + + /* Do simple duplicate message elimination */ + ent = &get_cpu_var(audit_cache); + if (profile == ent->profile && cap_raised(ent->caps, cap)) { + put_cpu_var(audit_cache); + if (COMPLAIN_MODE(profile)) + return complain_error(error); + return error; + } else { + aa_put_profile(ent->profile); + ent->profile = aa_get_profile(profile); + cap_raise(ent->caps, cap); + } + put_cpu_var(audit_cache); + + 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 + * @opts: CAP_OPT_NOAUDIT bit determines whether audit record is 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, + unsigned int opts, struct common_audit_data *sa) +{ + int error; + + if (cap_raised(profile->caps.allow, cap) && + !cap_raised(profile->caps.denied, cap)) + error = 0; + else + error = -EPERM; + + if (opts & CAP_OPT_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 + * @label: label being tested for capability (NOT NULL) + * @cap: capability to be tested + * @opts: CAP_OPT_NOAUDIT bit determines whether audit record is generated + * + * Look up capability in profile capability set. + * + * Returns: 0 on success, or else an error code. + */ +int aa_capable(struct aa_label *label, int cap, unsigned int opts) +{ + struct aa_profile *profile; + int error = 0; + DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_CAP, OP_CAPABLE); + + sa.u.cap = cap; + error = fn_for_each_confined(label, profile, + profile_capable(profile, cap, opts, &sa)); + + return error; +} |