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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /security/apparmor/domain.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'security/apparmor/domain.c')
-rw-r--r--security/apparmor/domain.c1464
1 files changed, 1464 insertions, 0 deletions
diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
new file mode 100644
index 000000000..f3715cda5
--- /dev/null
+++ b/security/apparmor/domain.c
@@ -0,0 +1,1464 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor policy attachment and domain transitions
+ *
+ * Copyright (C) 2002-2008 Novell/SUSE
+ * Copyright 2009-2010 Canonical Ltd.
+ */
+
+#include <linux/errno.h>
+#include <linux/fdtable.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/mount.h>
+#include <linux/syscalls.h>
+#include <linux/personality.h>
+#include <linux/xattr.h>
+#include <linux/user_namespace.h>
+
+#include "include/audit.h"
+#include "include/apparmorfs.h"
+#include "include/cred.h"
+#include "include/domain.h"
+#include "include/file.h"
+#include "include/ipc.h"
+#include "include/match.h"
+#include "include/path.h"
+#include "include/policy.h"
+#include "include/policy_ns.h"
+
+/**
+ * may_change_ptraced_domain - check if can change profile on ptraced task
+ * @to_label: profile to change to (NOT NULL)
+ * @info: message if there is an error
+ *
+ * Check if current is ptraced and if so if the tracing task is allowed
+ * to trace the new domain
+ *
+ * Returns: %0 or error if change not allowed
+ */
+static int may_change_ptraced_domain(struct aa_label *to_label,
+ const char **info)
+{
+ struct task_struct *tracer;
+ struct aa_label *tracerl = NULL;
+ int error = 0;
+
+ rcu_read_lock();
+ tracer = ptrace_parent(current);
+ if (tracer)
+ /* released below */
+ tracerl = aa_get_task_label(tracer);
+
+ /* not ptraced */
+ if (!tracer || unconfined(tracerl))
+ goto out;
+
+ error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH);
+
+out:
+ rcu_read_unlock();
+ aa_put_label(tracerl);
+
+ if (error)
+ *info = "ptrace prevents transition";
+ return error;
+}
+
+/**** TODO: dedup to aa_label_match - needs perm and dfa, merging
+ * specifically this is an exact copy of aa_label_match except
+ * aa_compute_perms is replaced with aa_compute_fperms
+ * and policy.dfa with file.dfa
+ ****/
+/* match a profile and its associated ns component if needed
+ * Assumes visibility test has already been done.
+ * If a subns profile is not to be matched should be prescreened with
+ * visibility test.
+ */
+static inline aa_state_t match_component(struct aa_profile *profile,
+ struct aa_profile *tp,
+ bool stack, aa_state_t state)
+{
+ struct aa_ruleset *rules = list_first_entry(&profile->rules,
+ typeof(*rules), list);
+ const char *ns_name;
+
+ if (stack)
+ state = aa_dfa_match(rules->file.dfa, state, "&");
+ if (profile->ns == tp->ns)
+ return aa_dfa_match(rules->file.dfa, state, tp->base.hname);
+
+ /* try matching with namespace name and then profile */
+ ns_name = aa_ns_name(profile->ns, tp->ns, true);
+ state = aa_dfa_match_len(rules->file.dfa, state, ":", 1);
+ state = aa_dfa_match(rules->file.dfa, state, ns_name);
+ state = aa_dfa_match_len(rules->file.dfa, state, ":", 1);
+ return aa_dfa_match(rules->file.dfa, state, tp->base.hname);
+}
+
+/**
+ * label_compound_match - find perms for full compound label
+ * @profile: profile to find perms for
+ * @label: label to check access permissions for
+ * @stack: whether this is a stacking request
+ * @state: state to start match in
+ * @subns: whether to do permission checks on components in a subns
+ * @request: permissions to request
+ * @perms: perms struct to set
+ *
+ * Returns: 0 on success else ERROR
+ *
+ * For the label A//&B//&C this does the perm match for A//&B//&C
+ * @perms should be preinitialized with allperms OR a previous permission
+ * check to be stacked.
+ */
+static int label_compound_match(struct aa_profile *profile,
+ struct aa_label *label, bool stack,
+ aa_state_t state, bool subns, u32 request,
+ struct aa_perms *perms)
+{
+ struct aa_ruleset *rules = list_first_entry(&profile->rules,
+ typeof(*rules), list);
+ struct aa_profile *tp;
+ struct label_it i;
+ struct path_cond cond = { };
+
+ /* find first subcomponent that is visible */
+ label_for_each(i, label, tp) {
+ if (!aa_ns_visible(profile->ns, tp->ns, subns))
+ continue;
+ state = match_component(profile, tp, stack, state);
+ if (!state)
+ goto fail;
+ goto next;
+ }
+
+ /* no component visible */
+ *perms = allperms;
+ return 0;
+
+next:
+ label_for_each_cont(i, label, tp) {
+ if (!aa_ns_visible(profile->ns, tp->ns, subns))
+ continue;
+ state = aa_dfa_match(rules->file.dfa, state, "//&");
+ state = match_component(profile, tp, false, state);
+ if (!state)
+ goto fail;
+ }
+ *perms = *(aa_lookup_fperms(&(rules->file), state, &cond));
+ aa_apply_modes_to_perms(profile, perms);
+ if ((perms->allow & request) != request)
+ return -EACCES;
+
+ return 0;
+
+fail:
+ *perms = nullperms;
+ return -EACCES;
+}
+
+/**
+ * label_components_match - find perms for all subcomponents of a label
+ * @profile: profile to find perms for
+ * @label: label to check access permissions for
+ * @stack: whether this is a stacking request
+ * @start: state to start match in
+ * @subns: whether to do permission checks on components in a subns
+ * @request: permissions to request
+ * @perms: an initialized perms struct to add accumulation to
+ *
+ * Returns: 0 on success else ERROR
+ *
+ * For the label A//&B//&C this does the perm match for each of A and B and C
+ * @perms should be preinitialized with allperms OR a previous permission
+ * check to be stacked.
+ */
+static int label_components_match(struct aa_profile *profile,
+ struct aa_label *label, bool stack,
+ aa_state_t start, bool subns, u32 request,
+ struct aa_perms *perms)
+{
+ struct aa_ruleset *rules = list_first_entry(&profile->rules,
+ typeof(*rules), list);
+ struct aa_profile *tp;
+ struct label_it i;
+ struct aa_perms tmp;
+ struct path_cond cond = { };
+ aa_state_t state = 0;
+
+ /* find first subcomponent to test */
+ label_for_each(i, label, tp) {
+ if (!aa_ns_visible(profile->ns, tp->ns, subns))
+ continue;
+ state = match_component(profile, tp, stack, start);
+ if (!state)
+ goto fail;
+ goto next;
+ }
+
+ /* no subcomponents visible - no change in perms */
+ return 0;
+
+next:
+ tmp = *(aa_lookup_fperms(&(rules->file), state, &cond));
+ aa_apply_modes_to_perms(profile, &tmp);
+ aa_perms_accum(perms, &tmp);
+ label_for_each_cont(i, label, tp) {
+ if (!aa_ns_visible(profile->ns, tp->ns, subns))
+ continue;
+ state = match_component(profile, tp, stack, start);
+ if (!state)
+ goto fail;
+ tmp = *(aa_lookup_fperms(&(rules->file), state, &cond));
+ aa_apply_modes_to_perms(profile, &tmp);
+ aa_perms_accum(perms, &tmp);
+ }
+
+ if ((perms->allow & request) != request)
+ return -EACCES;
+
+ return 0;
+
+fail:
+ *perms = nullperms;
+ return -EACCES;
+}
+
+/**
+ * label_match - do a multi-component label match
+ * @profile: profile to match against (NOT NULL)
+ * @label: label to match (NOT NULL)
+ * @stack: whether this is a stacking request
+ * @state: state to start in
+ * @subns: whether to match subns components
+ * @request: permission request
+ * @perms: Returns computed perms (NOT NULL)
+ *
+ * Returns: the state the match finished in, may be the none matching state
+ */
+static int label_match(struct aa_profile *profile, struct aa_label *label,
+ bool stack, aa_state_t state, bool subns, u32 request,
+ struct aa_perms *perms)
+{
+ int error;
+
+ *perms = nullperms;
+ error = label_compound_match(profile, label, stack, state, subns,
+ request, perms);
+ if (!error)
+ return error;
+
+ *perms = allperms;
+ return label_components_match(profile, label, stack, state, subns,
+ request, perms);
+}
+
+/******* end TODO: dedup *****/
+
+/**
+ * change_profile_perms - find permissions for change_profile
+ * @profile: the current profile (NOT NULL)
+ * @target: label to transition to (NOT NULL)
+ * @stack: whether this is a stacking request
+ * @request: requested perms
+ * @start: state to start matching in
+ *
+ *
+ * Returns: permission set
+ *
+ * currently only matches full label A//&B//&C or individual components A, B, C
+ * not arbitrary combinations. Eg. A//&B, C
+ */
+static int change_profile_perms(struct aa_profile *profile,
+ struct aa_label *target, bool stack,
+ u32 request, aa_state_t start,
+ struct aa_perms *perms)
+{
+ if (profile_unconfined(profile)) {
+ perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC;
+ perms->audit = perms->quiet = perms->kill = 0;
+ return 0;
+ }
+
+ /* TODO: add profile in ns screening */
+ return label_match(profile, target, stack, start, true, request, perms);
+}
+
+/**
+ * aa_xattrs_match - check whether a file matches the xattrs defined in profile
+ * @bprm: binprm struct for the process to validate
+ * @profile: profile to match against (NOT NULL)
+ * @state: state to start match in
+ *
+ * Returns: number of extended attributes that matched, or < 0 on error
+ */
+static int aa_xattrs_match(const struct linux_binprm *bprm,
+ struct aa_profile *profile, aa_state_t state)
+{
+ int i;
+ struct dentry *d;
+ char *value = NULL;
+ struct aa_attachment *attach = &profile->attach;
+ int size, value_size = 0, ret = attach->xattr_count;
+
+ if (!bprm || !attach->xattr_count)
+ return 0;
+ might_sleep();
+
+ /* transition from exec match to xattr set */
+ state = aa_dfa_outofband_transition(attach->xmatch.dfa, state);
+ d = bprm->file->f_path.dentry;
+
+ for (i = 0; i < attach->xattr_count; i++) {
+ size = vfs_getxattr_alloc(&nop_mnt_idmap, d, attach->xattrs[i],
+ &value, value_size, GFP_KERNEL);
+ if (size >= 0) {
+ u32 index, perm;
+
+ /*
+ * Check the xattr presence before value. This ensure
+ * that not present xattr can be distinguished from a 0
+ * length value or rule that matches any value
+ */
+ state = aa_dfa_null_transition(attach->xmatch.dfa,
+ state);
+ /* Check xattr value */
+ state = aa_dfa_match_len(attach->xmatch.dfa, state,
+ value, size);
+ index = ACCEPT_TABLE(attach->xmatch.dfa)[state];
+ perm = attach->xmatch.perms[index].allow;
+ if (!(perm & MAY_EXEC)) {
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+ /* transition to next element */
+ state = aa_dfa_outofband_transition(attach->xmatch.dfa, state);
+ if (size < 0) {
+ /*
+ * No xattr match, so verify if transition to
+ * next element was valid. IFF so the xattr
+ * was optional.
+ */
+ if (!state) {
+ ret = -EINVAL;
+ goto out;
+ }
+ /* don't count missing optional xattr as matched */
+ ret--;
+ }
+ }
+
+out:
+ kfree(value);
+ return ret;
+}
+
+/**
+ * find_attach - do attachment search for unconfined processes
+ * @bprm - binprm structure of transitioning task
+ * @ns: the current namespace (NOT NULL)
+ * @head - profile list to walk (NOT NULL)
+ * @name - to match against (NOT NULL)
+ * @info - info message if there was an error (NOT NULL)
+ *
+ * Do a linear search on the profiles in the list. There is a matching
+ * preference where an exact match is preferred over a name which uses
+ * expressions to match, and matching expressions with the greatest
+ * xmatch_len are preferred.
+ *
+ * Requires: @head not be shared or have appropriate locks held
+ *
+ * Returns: label or NULL if no match found
+ */
+static struct aa_label *find_attach(const struct linux_binprm *bprm,
+ struct aa_ns *ns, struct list_head *head,
+ const char *name, const char **info)
+{
+ int candidate_len = 0, candidate_xattrs = 0;
+ bool conflict = false;
+ struct aa_profile *profile, *candidate = NULL;
+
+ AA_BUG(!name);
+ AA_BUG(!head);
+
+ rcu_read_lock();
+restart:
+ list_for_each_entry_rcu(profile, head, base.list) {
+ struct aa_attachment *attach = &profile->attach;
+
+ if (profile->label.flags & FLAG_NULL &&
+ &profile->label == ns_unconfined(profile->ns))
+ continue;
+
+ /* Find the "best" matching profile. Profiles must
+ * match the path and extended attributes (if any)
+ * associated with the file. A more specific path
+ * match will be preferred over a less specific one,
+ * and a match with more matching extended attributes
+ * will be preferred over one with fewer. If the best
+ * match has both the same level of path specificity
+ * and the same number of matching extended attributes
+ * as another profile, signal a conflict and refuse to
+ * match.
+ */
+ if (attach->xmatch.dfa) {
+ unsigned int count;
+ aa_state_t state;
+ u32 index, perm;
+
+ state = aa_dfa_leftmatch(attach->xmatch.dfa,
+ attach->xmatch.start[AA_CLASS_XMATCH],
+ name, &count);
+ index = ACCEPT_TABLE(attach->xmatch.dfa)[state];
+ perm = attach->xmatch.perms[index].allow;
+ /* any accepting state means a valid match. */
+ if (perm & MAY_EXEC) {
+ int ret = 0;
+
+ if (count < candidate_len)
+ continue;
+
+ if (bprm && attach->xattr_count) {
+ long rev = READ_ONCE(ns->revision);
+
+ if (!aa_get_profile_not0(profile))
+ goto restart;
+ rcu_read_unlock();
+ ret = aa_xattrs_match(bprm, profile,
+ state);
+ rcu_read_lock();
+ aa_put_profile(profile);
+ if (rev !=
+ READ_ONCE(ns->revision))
+ /* policy changed */
+ goto restart;
+ /*
+ * Fail matching if the xattrs don't
+ * match
+ */
+ if (ret < 0)
+ continue;
+ }
+ /*
+ * TODO: allow for more flexible best match
+ *
+ * The new match isn't more specific
+ * than the current best match
+ */
+ if (count == candidate_len &&
+ ret <= candidate_xattrs) {
+ /* Match is equivalent, so conflict */
+ if (ret == candidate_xattrs)
+ conflict = true;
+ continue;
+ }
+
+ /* Either the same length with more matching
+ * xattrs, or a longer match
+ */
+ candidate = profile;
+ candidate_len = max(count, attach->xmatch_len);
+ candidate_xattrs = ret;
+ conflict = false;
+ }
+ } else if (!strcmp(profile->base.name, name)) {
+ /*
+ * old exact non-re match, without conditionals such
+ * as xattrs. no more searching required
+ */
+ candidate = profile;
+ goto out;
+ }
+ }
+
+ if (!candidate || conflict) {
+ if (conflict)
+ *info = "conflicting profile attachments";
+ rcu_read_unlock();
+ return NULL;
+ }
+
+out:
+ candidate = aa_get_newest_profile(candidate);
+ rcu_read_unlock();
+
+ return &candidate->label;
+}
+
+static const char *next_name(int xtype, const char *name)
+{
+ return NULL;
+}
+
+/**
+ * x_table_lookup - lookup an x transition name via transition table
+ * @profile: current profile (NOT NULL)
+ * @xindex: index into x transition table
+ * @name: returns: name tested to find label (NOT NULL)
+ *
+ * Returns: refcounted label, or NULL on failure (MAYBE NULL)
+ */
+struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex,
+ const char **name)
+{
+ struct aa_ruleset *rules = list_first_entry(&profile->rules,
+ typeof(*rules), list);
+ struct aa_label *label = NULL;
+ u32 xtype = xindex & AA_X_TYPE_MASK;
+ int index = xindex & AA_X_INDEX_MASK;
+
+ AA_BUG(!name);
+
+ /* index is guaranteed to be in range, validated at load time */
+ /* TODO: move lookup parsing to unpack time so this is a straight
+ * index into the resultant label
+ */
+ for (*name = rules->file.trans.table[index]; !label && *name;
+ *name = next_name(xtype, *name)) {
+ if (xindex & AA_X_CHILD) {
+ struct aa_profile *new_profile;
+ /* release by caller */
+ new_profile = aa_find_child(profile, *name);
+ if (new_profile)
+ label = &new_profile->label;
+ continue;
+ }
+ label = aa_label_parse(&profile->label, *name, GFP_KERNEL,
+ true, false);
+ if (IS_ERR(label))
+ label = NULL;
+ }
+
+ /* released by caller */
+
+ return label;
+}
+
+/**
+ * x_to_label - get target label for a given xindex
+ * @profile: current profile (NOT NULL)
+ * @bprm: binprm structure of transitioning task
+ * @name: name to lookup (NOT NULL)
+ * @xindex: index into x transition table
+ * @lookupname: returns: name used in lookup if one was specified (NOT NULL)
+ *
+ * find label for a transition index
+ *
+ * Returns: refcounted label or NULL if not found available
+ */
+static struct aa_label *x_to_label(struct aa_profile *profile,
+ const struct linux_binprm *bprm,
+ const char *name, u32 xindex,
+ const char **lookupname,
+ const char **info)
+{
+ struct aa_ruleset *rules = list_first_entry(&profile->rules,
+ typeof(*rules), list);
+ struct aa_label *new = NULL;
+ struct aa_ns *ns = profile->ns;
+ u32 xtype = xindex & AA_X_TYPE_MASK;
+ const char *stack = NULL;
+
+ switch (xtype) {
+ case AA_X_NONE:
+ /* fail exec unless ix || ux fallback - handled by caller */
+ *lookupname = NULL;
+ break;
+ case AA_X_TABLE:
+ /* TODO: fix when perm mapping done at unload */
+ stack = rules->file.trans.table[xindex & AA_X_INDEX_MASK];
+ if (*stack != '&') {
+ /* released by caller */
+ new = x_table_lookup(profile, xindex, lookupname);
+ stack = NULL;
+ break;
+ }
+ fallthrough; /* to X_NAME */
+ case AA_X_NAME:
+ if (xindex & AA_X_CHILD)
+ /* released by caller */
+ new = find_attach(bprm, ns, &profile->base.profiles,
+ name, info);
+ else
+ /* released by caller */
+ new = find_attach(bprm, ns, &ns->base.profiles,
+ name, info);
+ *lookupname = name;
+ break;
+ }
+
+ if (!new) {
+ if (xindex & AA_X_INHERIT) {
+ /* (p|c|n)ix - don't change profile but do
+ * use the newest version
+ */
+ *info = "ix fallback";
+ /* no profile && no error */
+ new = aa_get_newest_label(&profile->label);
+ } else if (xindex & AA_X_UNCONFINED) {
+ new = aa_get_newest_label(ns_unconfined(profile->ns));
+ *info = "ux fallback";
+ }
+ }
+
+ if (new && stack) {
+ /* base the stack on post domain transition */
+ struct aa_label *base = new;
+
+ new = aa_label_parse(base, stack, GFP_KERNEL, true, false);
+ if (IS_ERR(new))
+ new = NULL;
+ aa_put_label(base);
+ }
+
+ /* released by caller */
+ return new;
+}
+
+static struct aa_label *profile_transition(struct aa_profile *profile,
+ const struct linux_binprm *bprm,
+ char *buffer, struct path_cond *cond,
+ bool *secure_exec)
+{
+ struct aa_ruleset *rules = list_first_entry(&profile->rules,
+ typeof(*rules), list);
+ struct aa_label *new = NULL;
+ const char *info = NULL, *name = NULL, *target = NULL;
+ aa_state_t state = rules->file.start[AA_CLASS_FILE];
+ struct aa_perms perms = {};
+ bool nonewprivs = false;
+ int error = 0;
+
+ AA_BUG(!profile);
+ AA_BUG(!bprm);
+ AA_BUG(!buffer);
+
+ error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
+ &name, &info, profile->disconnected);
+ if (error) {
+ if (profile_unconfined(profile) ||
+ (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
+ AA_DEBUG("name lookup ix on error");
+ error = 0;
+ new = aa_get_newest_label(&profile->label);
+ }
+ name = bprm->filename;
+ goto audit;
+ }
+
+ if (profile_unconfined(profile)) {
+ new = find_attach(bprm, profile->ns,
+ &profile->ns->base.profiles, name, &info);
+ if (new) {
+ AA_DEBUG("unconfined attached to new label");
+ return new;
+ }
+ AA_DEBUG("unconfined exec no attachment");
+ return aa_get_newest_label(&profile->label);
+ }
+
+ /* find exec permissions for name */
+ state = aa_str_perms(&(rules->file), state, name, cond, &perms);
+ if (perms.allow & MAY_EXEC) {
+ /* exec permission determine how to transition */
+ new = x_to_label(profile, bprm, name, perms.xindex, &target,
+ &info);
+ if (new && new->proxy == profile->label.proxy && info) {
+ /* hack ix fallback - improve how this is detected */
+ goto audit;
+ } else if (!new) {
+ error = -EACCES;
+ info = "profile transition not found";
+ /* remove MAY_EXEC to audit as failure */
+ perms.allow &= ~MAY_EXEC;
+ }
+ } else if (COMPLAIN_MODE(profile)) {
+ /* no exec permission - learning mode */
+ struct aa_profile *new_profile = NULL;
+
+ new_profile = aa_new_learning_profile(profile, false, name,
+ GFP_KERNEL);
+ if (!new_profile) {
+ error = -ENOMEM;
+ info = "could not create null profile";
+ } else {
+ error = -EACCES;
+ new = &new_profile->label;
+ }
+ perms.xindex |= AA_X_UNSAFE;
+ } else
+ /* fail exec */
+ error = -EACCES;
+
+ if (!new)
+ goto audit;
+
+
+ if (!(perms.xindex & AA_X_UNSAFE)) {
+ if (DEBUG_ON) {
+ dbg_printk("apparmor: scrubbing environment variables"
+ " for %s profile=", name);
+ aa_label_printk(new, GFP_KERNEL);
+ dbg_printk("\n");
+ }
+ *secure_exec = true;
+ }
+
+audit:
+ aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new,
+ cond->uid, info, error);
+ if (!new || nonewprivs) {
+ aa_put_label(new);
+ return ERR_PTR(error);
+ }
+
+ return new;
+}
+
+static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec,
+ bool stack, const struct linux_binprm *bprm,
+ char *buffer, struct path_cond *cond,
+ bool *secure_exec)
+{
+ struct aa_ruleset *rules = list_first_entry(&profile->rules,
+ typeof(*rules), list);
+ aa_state_t state = rules->file.start[AA_CLASS_FILE];
+ struct aa_perms perms = {};
+ const char *xname = NULL, *info = "change_profile onexec";
+ int error = -EACCES;
+
+ AA_BUG(!profile);
+ AA_BUG(!onexec);
+ AA_BUG(!bprm);
+ AA_BUG(!buffer);
+
+ if (profile_unconfined(profile)) {
+ /* change_profile on exec already granted */
+ /*
+ * NOTE: Domain transitions from unconfined are allowed
+ * even when no_new_privs is set because this aways results
+ * in a further reduction of permissions.
+ */
+ return 0;
+ }
+
+ error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
+ &xname, &info, profile->disconnected);
+ if (error) {
+ if (profile_unconfined(profile) ||
+ (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
+ AA_DEBUG("name lookup ix on error");
+ error = 0;
+ }
+ xname = bprm->filename;
+ goto audit;
+ }
+
+ /* find exec permissions for name */
+ state = aa_str_perms(&(rules->file), state, xname, cond, &perms);
+ if (!(perms.allow & AA_MAY_ONEXEC)) {
+ info = "no change_onexec valid for executable";
+ goto audit;
+ }
+ /* test if this exec can be paired with change_profile onexec.
+ * onexec permission is linked to exec with a standard pairing
+ * exec\0change_profile
+ */
+ state = aa_dfa_null_transition(rules->file.dfa, state);
+ error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC,
+ state, &perms);
+ if (error) {
+ perms.allow &= ~AA_MAY_ONEXEC;
+ goto audit;
+ }
+
+ if (!(perms.xindex & AA_X_UNSAFE)) {
+ if (DEBUG_ON) {
+ dbg_printk("apparmor: scrubbing environment "
+ "variables for %s label=", xname);
+ aa_label_printk(onexec, GFP_KERNEL);
+ dbg_printk("\n");
+ }
+ *secure_exec = true;
+ }
+
+audit:
+ return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname,
+ NULL, onexec, cond->uid, info, error);
+}
+
+/* ensure none ns domain transitions are correctly applied with onexec */
+
+static struct aa_label *handle_onexec(struct aa_label *label,
+ struct aa_label *onexec, bool stack,
+ const struct linux_binprm *bprm,
+ char *buffer, struct path_cond *cond,
+ bool *unsafe)
+{
+ struct aa_profile *profile;
+ struct aa_label *new;
+ int error;
+
+ AA_BUG(!label);
+ AA_BUG(!onexec);
+ AA_BUG(!bprm);
+ AA_BUG(!buffer);
+
+ if (!stack) {
+ error = fn_for_each_in_ns(label, profile,
+ profile_onexec(profile, onexec, stack,
+ bprm, buffer, cond, unsafe));
+ if (error)
+ return ERR_PTR(error);
+ new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
+ aa_get_newest_label(onexec),
+ profile_transition(profile, bprm, buffer,
+ cond, unsafe));
+
+ } else {
+ /* TODO: determine how much we want to loosen this */
+ error = fn_for_each_in_ns(label, profile,
+ profile_onexec(profile, onexec, stack, bprm,
+ buffer, cond, unsafe));
+ if (error)
+ return ERR_PTR(error);
+ new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
+ aa_label_merge(&profile->label, onexec,
+ GFP_KERNEL),
+ profile_transition(profile, bprm, buffer,
+ cond, unsafe));
+ }
+
+ if (new)
+ return new;
+
+ /* TODO: get rid of GLOBAL_ROOT_UID */
+ error = fn_for_each_in_ns(label, profile,
+ aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC,
+ AA_MAY_ONEXEC, bprm->filename, NULL,
+ onexec, GLOBAL_ROOT_UID,
+ "failed to build target label", -ENOMEM));
+ return ERR_PTR(error);
+}
+
+/**
+ * apparmor_bprm_creds_for_exec - Update the new creds on the bprm struct
+ * @bprm: binprm for the exec (NOT NULL)
+ *
+ * Returns: %0 or error on failure
+ *
+ * TODO: once the other paths are done see if we can't refactor into a fn
+ */
+int apparmor_bprm_creds_for_exec(struct linux_binprm *bprm)
+{
+ struct aa_task_ctx *ctx;
+ struct aa_label *label, *new = NULL;
+ struct aa_profile *profile;
+ char *buffer = NULL;
+ const char *info = NULL;
+ int error = 0;
+ bool unsafe = false;
+ vfsuid_t vfsuid = i_uid_into_vfsuid(file_mnt_idmap(bprm->file),
+ file_inode(bprm->file));
+ struct path_cond cond = {
+ vfsuid_into_kuid(vfsuid),
+ file_inode(bprm->file)->i_mode
+ };
+
+ ctx = task_ctx(current);
+ AA_BUG(!cred_label(bprm->cred));
+ AA_BUG(!ctx);
+
+ label = aa_get_newest_label(cred_label(bprm->cred));
+
+ /*
+ * Detect no new privs being set, and store the label it
+ * occurred under. Ideally this would happen when nnp
+ * is set but there isn't a good way to do that yet.
+ *
+ * Testing for unconfined must be done before the subset test
+ */
+ if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && !unconfined(label) &&
+ !ctx->nnp)
+ ctx->nnp = aa_get_label(label);
+
+ /* buffer freed below, name is pointer into buffer */
+ buffer = aa_get_buffer(false);
+ if (!buffer) {
+ error = -ENOMEM;
+ goto done;
+ }
+
+ /* Test for onexec first as onexec override other x transitions. */
+ if (ctx->onexec)
+ new = handle_onexec(label, ctx->onexec, ctx->token,
+ bprm, buffer, &cond, &unsafe);
+ else
+ new = fn_label_build(label, profile, GFP_KERNEL,
+ profile_transition(profile, bprm, buffer,
+ &cond, &unsafe));
+
+ AA_BUG(!new);
+ if (IS_ERR(new)) {
+ error = PTR_ERR(new);
+ goto done;
+ } else if (!new) {
+ error = -ENOMEM;
+ goto done;
+ }
+
+ /* Policy has specified a domain transitions. If no_new_privs and
+ * confined ensure the transition is to confinement that is subset
+ * of the confinement when the task entered no new privs.
+ *
+ * NOTE: Domain transitions from unconfined and to stacked
+ * subsets are allowed even when no_new_privs is set because this
+ * aways results in a further reduction of permissions.
+ */
+ if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) &&
+ !unconfined(label) &&
+ !aa_label_is_unconfined_subset(new, ctx->nnp)) {
+ error = -EPERM;
+ info = "no new privs";
+ goto audit;
+ }
+
+ if (bprm->unsafe & LSM_UNSAFE_SHARE) {
+ /* FIXME: currently don't mediate shared state */
+ ;
+ }
+
+ if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) {
+ /* TODO: test needs to be profile of label to new */
+ error = may_change_ptraced_domain(new, &info);
+ if (error)
+ goto audit;
+ }
+
+ if (unsafe) {
+ if (DEBUG_ON) {
+ dbg_printk("scrubbing environment variables for %s "
+ "label=", bprm->filename);
+ aa_label_printk(new, GFP_KERNEL);
+ dbg_printk("\n");
+ }
+ bprm->secureexec = 1;
+ }
+
+ if (label->proxy != new->proxy) {
+ /* when transitioning clear unsafe personality bits */
+ if (DEBUG_ON) {
+ dbg_printk("apparmor: clearing unsafe personality "
+ "bits. %s label=", bprm->filename);
+ aa_label_printk(new, GFP_KERNEL);
+ dbg_printk("\n");
+ }
+ bprm->per_clear |= PER_CLEAR_ON_SETID;
+ }
+ aa_put_label(cred_label(bprm->cred));
+ /* transfer reference, released when cred is freed */
+ set_cred_label(bprm->cred, new);
+
+done:
+ aa_put_label(label);
+ aa_put_buffer(buffer);
+
+ return error;
+
+audit:
+ error = fn_for_each(label, profile,
+ aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC,
+ bprm->filename, NULL, new,
+ vfsuid_into_kuid(vfsuid), info, error));
+ aa_put_label(new);
+ goto done;
+}
+
+/*
+ * Functions for self directed profile change
+ */
+
+
+/* helper fn for change_hat
+ *
+ * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL
+ */
+static struct aa_label *build_change_hat(struct aa_profile *profile,
+ const char *name, bool sibling)
+{
+ struct aa_profile *root, *hat = NULL;
+ const char *info = NULL;
+ int error = 0;
+
+ if (sibling && PROFILE_IS_HAT(profile)) {
+ root = aa_get_profile_rcu(&profile->parent);
+ } else if (!sibling && !PROFILE_IS_HAT(profile)) {
+ root = aa_get_profile(profile);
+ } else {
+ info = "conflicting target types";
+ error = -EPERM;
+ goto audit;
+ }
+
+ hat = aa_find_child(root, name);
+ if (!hat) {
+ error = -ENOENT;
+ if (COMPLAIN_MODE(profile)) {
+ hat = aa_new_learning_profile(profile, true, name,
+ GFP_KERNEL);
+ if (!hat) {
+ info = "failed null profile create";
+ error = -ENOMEM;
+ }
+ }
+ }
+ aa_put_profile(root);
+
+audit:
+ aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT,
+ name, hat ? hat->base.hname : NULL,
+ hat ? &hat->label : NULL, GLOBAL_ROOT_UID, info,
+ error);
+ if (!hat || (error && error != -ENOENT))
+ return ERR_PTR(error);
+ /* if hat && error - complain mode, already audited and we adjust for
+ * complain mode allow by returning hat->label
+ */
+ return &hat->label;
+}
+
+/* helper fn for changing into a hat
+ *
+ * Returns: label for hat transition or ERR_PTR. Does not return NULL
+ */
+static struct aa_label *change_hat(struct aa_label *label, const char *hats[],
+ int count, int flags)
+{
+ struct aa_profile *profile, *root, *hat = NULL;
+ struct aa_label *new;
+ struct label_it it;
+ bool sibling = false;
+ const char *name, *info = NULL;
+ int i, error;
+
+ AA_BUG(!label);
+ AA_BUG(!hats);
+ AA_BUG(count < 1);
+
+ if (PROFILE_IS_HAT(labels_profile(label)))
+ sibling = true;
+
+ /*find first matching hat */
+ for (i = 0; i < count && !hat; i++) {
+ name = hats[i];
+ label_for_each_in_ns(it, labels_ns(label), label, profile) {
+ if (sibling && PROFILE_IS_HAT(profile)) {
+ root = aa_get_profile_rcu(&profile->parent);
+ } else if (!sibling && !PROFILE_IS_HAT(profile)) {
+ root = aa_get_profile(profile);
+ } else { /* conflicting change type */
+ info = "conflicting targets types";
+ error = -EPERM;
+ goto fail;
+ }
+ hat = aa_find_child(root, name);
+ aa_put_profile(root);
+ if (!hat) {
+ if (!COMPLAIN_MODE(profile))
+ goto outer_continue;
+ /* complain mode succeed as if hat */
+ } else if (!PROFILE_IS_HAT(hat)) {
+ info = "target not hat";
+ error = -EPERM;
+ aa_put_profile(hat);
+ goto fail;
+ }
+ aa_put_profile(hat);
+ }
+ /* found a hat for all profiles in ns */
+ goto build;
+outer_continue:
+ ;
+ }
+ /* no hats that match, find appropriate error
+ *
+ * In complain mode audit of the failure is based off of the first
+ * hat supplied. This is done due how userspace interacts with
+ * change_hat.
+ */
+ name = NULL;
+ label_for_each_in_ns(it, labels_ns(label), label, profile) {
+ if (!list_empty(&profile->base.profiles)) {
+ info = "hat not found";
+ error = -ENOENT;
+ goto fail;
+ }
+ }
+ info = "no hats defined";
+ error = -ECHILD;
+
+fail:
+ label_for_each_in_ns(it, labels_ns(label), label, profile) {
+ /*
+ * no target as it has failed to be found or built
+ *
+ * change_hat uses probing and should not log failures
+ * related to missing hats
+ */
+ /* TODO: get rid of GLOBAL_ROOT_UID */
+ if (count > 1 || COMPLAIN_MODE(profile)) {
+ aa_audit_file(profile, &nullperms, OP_CHANGE_HAT,
+ AA_MAY_CHANGEHAT, name, NULL, NULL,
+ GLOBAL_ROOT_UID, info, error);
+ }
+ }
+ return ERR_PTR(error);
+
+build:
+ new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
+ build_change_hat(profile, name, sibling),
+ aa_get_label(&profile->label));
+ if (!new) {
+ info = "label build failed";
+ error = -ENOMEM;
+ goto fail;
+ } /* else if (IS_ERR) build_change_hat has logged error so return new */
+
+ return new;
+}
+
+/**
+ * aa_change_hat - change hat to/from subprofile
+ * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0)
+ * @count: number of hat names in @hats
+ * @token: magic value to validate the hat change
+ * @flags: flags affecting behavior of the change
+ *
+ * Returns %0 on success, error otherwise.
+ *
+ * Change to the first profile specified in @hats that exists, and store
+ * the @hat_magic in the current task context. If the count == 0 and the
+ * @token matches that stored in the current task context, return to the
+ * top level profile.
+ *
+ * change_hat only applies to profiles in the current ns, and each profile
+ * in the ns must make the same transition otherwise change_hat will fail.
+ */
+int aa_change_hat(const char *hats[], int count, u64 token, int flags)
+{
+ const struct cred *cred;
+ struct aa_task_ctx *ctx = task_ctx(current);
+ struct aa_label *label, *previous, *new = NULL, *target = NULL;
+ struct aa_profile *profile;
+ struct aa_perms perms = {};
+ const char *info = NULL;
+ int error = 0;
+
+ /* released below */
+ cred = get_current_cred();
+ label = aa_get_newest_cred_label(cred);
+ previous = aa_get_newest_label(ctx->previous);
+
+ /*
+ * Detect no new privs being set, and store the label it
+ * occurred under. Ideally this would happen when nnp
+ * is set but there isn't a good way to do that yet.
+ *
+ * Testing for unconfined must be done before the subset test
+ */
+ if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp)
+ ctx->nnp = aa_get_label(label);
+
+ if (unconfined(label)) {
+ info = "unconfined can not change_hat";
+ error = -EPERM;
+ goto fail;
+ }
+
+ if (count) {
+ new = change_hat(label, hats, count, flags);
+ AA_BUG(!new);
+ if (IS_ERR(new)) {
+ error = PTR_ERR(new);
+ new = NULL;
+ /* already audited */
+ goto out;
+ }
+
+ error = may_change_ptraced_domain(new, &info);
+ if (error)
+ goto fail;
+
+ /*
+ * no new privs prevents domain transitions that would
+ * reduce restrictions.
+ */
+ if (task_no_new_privs(current) && !unconfined(label) &&
+ !aa_label_is_unconfined_subset(new, ctx->nnp)) {
+ /* not an apparmor denial per se, so don't log it */
+ AA_DEBUG("no_new_privs - change_hat denied");
+ error = -EPERM;
+ goto out;
+ }
+
+ if (flags & AA_CHANGE_TEST)
+ goto out;
+
+ target = new;
+ error = aa_set_current_hat(new, token);
+ if (error == -EACCES)
+ /* kill task in case of brute force attacks */
+ goto kill;
+ } else if (previous && !(flags & AA_CHANGE_TEST)) {
+ /*
+ * no new privs prevents domain transitions that would
+ * reduce restrictions.
+ */
+ if (task_no_new_privs(current) && !unconfined(label) &&
+ !aa_label_is_unconfined_subset(previous, ctx->nnp)) {
+ /* not an apparmor denial per se, so don't log it */
+ AA_DEBUG("no_new_privs - change_hat denied");
+ error = -EPERM;
+ goto out;
+ }
+
+ /* Return to saved label. Kill task if restore fails
+ * to avoid brute force attacks
+ */
+ target = previous;
+ error = aa_restore_previous_label(token);
+ if (error) {
+ if (error == -EACCES)
+ goto kill;
+ goto fail;
+ }
+ } /* else ignore @flags && restores when there is no saved profile */
+
+out:
+ aa_put_label(new);
+ aa_put_label(previous);
+ aa_put_label(label);
+ put_cred(cred);
+
+ return error;
+
+kill:
+ info = "failed token match";
+ perms.kill = AA_MAY_CHANGEHAT;
+
+fail:
+ fn_for_each_in_ns(label, profile,
+ aa_audit_file(profile, &perms, OP_CHANGE_HAT,
+ AA_MAY_CHANGEHAT, NULL, NULL, target,
+ GLOBAL_ROOT_UID, info, error));
+
+ goto out;
+}
+
+
+static int change_profile_perms_wrapper(const char *op, const char *name,
+ struct aa_profile *profile,
+ struct aa_label *target, bool stack,
+ u32 request, struct aa_perms *perms)
+{
+ struct aa_ruleset *rules = list_first_entry(&profile->rules,
+ typeof(*rules), list);
+ const char *info = NULL;
+ int error = 0;
+
+ if (!error)
+ error = change_profile_perms(profile, target, stack, request,
+ rules->file.start[AA_CLASS_FILE],
+ perms);
+ if (error)
+ error = aa_audit_file(profile, perms, op, request, name,
+ NULL, target, GLOBAL_ROOT_UID, info,
+ error);
+
+ return error;
+}
+
+/**
+ * aa_change_profile - perform a one-way profile transition
+ * @fqname: name of profile may include namespace (NOT NULL)
+ * @flags: flags affecting change behavior
+ *
+ * Change to new profile @name. Unlike with hats, there is no way
+ * to change back. If @name isn't specified the current profile name is
+ * used.
+ * If @onexec then the transition is delayed until
+ * the next exec.
+ *
+ * Returns %0 on success, error otherwise.
+ */
+int aa_change_profile(const char *fqname, int flags)
+{
+ struct aa_label *label, *new = NULL, *target = NULL;
+ struct aa_profile *profile;
+ struct aa_perms perms = {};
+ const char *info = NULL;
+ const char *auditname = fqname; /* retain leading & if stack */
+ bool stack = flags & AA_CHANGE_STACK;
+ struct aa_task_ctx *ctx = task_ctx(current);
+ int error = 0;
+ char *op;
+ u32 request;
+
+ label = aa_get_current_label();
+
+ /*
+ * Detect no new privs being set, and store the label it
+ * occurred under. Ideally this would happen when nnp
+ * is set but there isn't a good way to do that yet.
+ *
+ * Testing for unconfined must be done before the subset test
+ */
+ if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp)
+ ctx->nnp = aa_get_label(label);
+
+ if (!fqname || !*fqname) {
+ aa_put_label(label);
+ AA_DEBUG("no profile name");
+ return -EINVAL;
+ }
+
+ if (flags & AA_CHANGE_ONEXEC) {
+ request = AA_MAY_ONEXEC;
+ if (stack)
+ op = OP_STACK_ONEXEC;
+ else
+ op = OP_CHANGE_ONEXEC;
+ } else {
+ request = AA_MAY_CHANGE_PROFILE;
+ if (stack)
+ op = OP_STACK;
+ else
+ op = OP_CHANGE_PROFILE;
+ }
+
+ if (*fqname == '&') {
+ stack = true;
+ /* don't have label_parse() do stacking */
+ fqname++;
+ }
+ target = aa_label_parse(label, fqname, GFP_KERNEL, true, false);
+ if (IS_ERR(target)) {
+ struct aa_profile *tprofile;
+
+ info = "label not found";
+ error = PTR_ERR(target);
+ target = NULL;
+ /*
+ * TODO: fixme using labels_profile is not right - do profile
+ * per complain profile
+ */
+ if ((flags & AA_CHANGE_TEST) ||
+ !COMPLAIN_MODE(labels_profile(label)))
+ goto audit;
+ /* released below */
+ tprofile = aa_new_learning_profile(labels_profile(label), false,
+ fqname, GFP_KERNEL);
+ if (!tprofile) {
+ info = "failed null profile create";
+ error = -ENOMEM;
+ goto audit;
+ }
+ target = &tprofile->label;
+ goto check;
+ }
+
+ /*
+ * self directed transitions only apply to current policy ns
+ * TODO: currently requiring perms for stacking and straight change
+ * stacking doesn't strictly need this. Determine how much
+ * we want to loosen this restriction for stacking
+ *
+ * if (!stack) {
+ */
+ error = fn_for_each_in_ns(label, profile,
+ change_profile_perms_wrapper(op, auditname,
+ profile, target, stack,
+ request, &perms));
+ if (error)
+ /* auditing done in change_profile_perms_wrapper */
+ goto out;
+
+ /* } */
+
+check:
+ /* check if tracing task is allowed to trace target domain */
+ error = may_change_ptraced_domain(target, &info);
+ if (error && !fn_for_each_in_ns(label, profile,
+ COMPLAIN_MODE(profile)))
+ goto audit;
+
+ /* TODO: add permission check to allow this
+ * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) {
+ * info = "not a single threaded task";
+ * error = -EACCES;
+ * goto audit;
+ * }
+ */
+ if (flags & AA_CHANGE_TEST)
+ goto out;
+
+ /* stacking is always a subset, so only check the nonstack case */
+ if (!stack) {
+ new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
+ aa_get_label(target),
+ aa_get_label(&profile->label));
+ /*
+ * no new privs prevents domain transitions that would
+ * reduce restrictions.
+ */
+ if (task_no_new_privs(current) && !unconfined(label) &&
+ !aa_label_is_unconfined_subset(new, ctx->nnp)) {
+ /* not an apparmor denial per se, so don't log it */
+ AA_DEBUG("no_new_privs - change_hat denied");
+ error = -EPERM;
+ goto out;
+ }
+ }
+
+ if (!(flags & AA_CHANGE_ONEXEC)) {
+ /* only transition profiles in the current ns */
+ if (stack)
+ new = aa_label_merge(label, target, GFP_KERNEL);
+ if (IS_ERR_OR_NULL(new)) {
+ info = "failed to build target label";
+ if (!new)
+ error = -ENOMEM;
+ else
+ error = PTR_ERR(new);
+ new = NULL;
+ perms.allow = 0;
+ goto audit;
+ }
+ error = aa_replace_current_label(new);
+ } else {
+ if (new) {
+ aa_put_label(new);
+ new = NULL;
+ }
+
+ /* full transition will be built in exec path */
+ error = aa_set_current_onexec(target, stack);
+ }
+
+audit:
+ error = fn_for_each_in_ns(label, profile,
+ aa_audit_file(profile, &perms, op, request, auditname,
+ NULL, new ? new : target,
+ GLOBAL_ROOT_UID, info, error));
+
+out:
+ aa_put_label(new);
+ aa_put_label(target);
+ aa_put_label(label);
+
+ return error;
+}