aboutsummaryrefslogtreecommitdiff
path: root/fs/afs/security.c
diff options
context:
space:
mode:
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 /fs/afs/security.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 '')
-rw-r--r--fs/afs/security.c487
1 files changed, 487 insertions, 0 deletions
diff --git a/fs/afs/security.c b/fs/afs/security.c
new file mode 100644
index 000000000..6a7744c9e
--- /dev/null
+++ b/fs/afs/security.c
@@ -0,0 +1,487 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* AFS security handling
+ *
+ * Copyright (C) 2007, 2017 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/ctype.h>
+#include <linux/sched.h>
+#include <linux/hashtable.h>
+#include <keys/rxrpc-type.h>
+#include "internal.h"
+
+static DEFINE_HASHTABLE(afs_permits_cache, 10);
+static DEFINE_SPINLOCK(afs_permits_lock);
+
+/*
+ * get a key
+ */
+struct key *afs_request_key(struct afs_cell *cell)
+{
+ struct key *key;
+
+ _enter("{%x}", key_serial(cell->anonymous_key));
+
+ _debug("key %s", cell->anonymous_key->description);
+ key = request_key_net(&key_type_rxrpc, cell->anonymous_key->description,
+ cell->net->net, NULL);
+ if (IS_ERR(key)) {
+ if (PTR_ERR(key) != -ENOKEY) {
+ _leave(" = %ld", PTR_ERR(key));
+ return key;
+ }
+
+ /* act as anonymous user */
+ _leave(" = {%x} [anon]", key_serial(cell->anonymous_key));
+ return key_get(cell->anonymous_key);
+ } else {
+ /* act as authorised user */
+ _leave(" = {%x} [auth]", key_serial(key));
+ return key;
+ }
+}
+
+/*
+ * Get a key when pathwalk is in rcuwalk mode.
+ */
+struct key *afs_request_key_rcu(struct afs_cell *cell)
+{
+ struct key *key;
+
+ _enter("{%x}", key_serial(cell->anonymous_key));
+
+ _debug("key %s", cell->anonymous_key->description);
+ key = request_key_net_rcu(&key_type_rxrpc,
+ cell->anonymous_key->description,
+ cell->net->net);
+ if (IS_ERR(key)) {
+ if (PTR_ERR(key) != -ENOKEY) {
+ _leave(" = %ld", PTR_ERR(key));
+ return key;
+ }
+
+ /* act as anonymous user */
+ _leave(" = {%x} [anon]", key_serial(cell->anonymous_key));
+ return key_get(cell->anonymous_key);
+ } else {
+ /* act as authorised user */
+ _leave(" = {%x} [auth]", key_serial(key));
+ return key;
+ }
+}
+
+/*
+ * Dispose of a list of permits.
+ */
+static void afs_permits_rcu(struct rcu_head *rcu)
+{
+ struct afs_permits *permits =
+ container_of(rcu, struct afs_permits, rcu);
+ int i;
+
+ for (i = 0; i < permits->nr_permits; i++)
+ key_put(permits->permits[i].key);
+ kfree(permits);
+}
+
+/*
+ * Discard a permission cache.
+ */
+void afs_put_permits(struct afs_permits *permits)
+{
+ if (permits && refcount_dec_and_test(&permits->usage)) {
+ spin_lock(&afs_permits_lock);
+ hash_del_rcu(&permits->hash_node);
+ spin_unlock(&afs_permits_lock);
+ call_rcu(&permits->rcu, afs_permits_rcu);
+ }
+}
+
+/*
+ * Clear a permit cache on callback break.
+ */
+void afs_clear_permits(struct afs_vnode *vnode)
+{
+ struct afs_permits *permits;
+
+ spin_lock(&vnode->lock);
+ permits = rcu_dereference_protected(vnode->permit_cache,
+ lockdep_is_held(&vnode->lock));
+ RCU_INIT_POINTER(vnode->permit_cache, NULL);
+ spin_unlock(&vnode->lock);
+
+ afs_put_permits(permits);
+}
+
+/*
+ * Hash a list of permits. Use simple addition to make it easy to add an extra
+ * one at an as-yet indeterminate position in the list.
+ */
+static void afs_hash_permits(struct afs_permits *permits)
+{
+ unsigned long h = permits->nr_permits;
+ int i;
+
+ for (i = 0; i < permits->nr_permits; i++) {
+ h += (unsigned long)permits->permits[i].key / sizeof(void *);
+ h += permits->permits[i].access;
+ }
+
+ permits->h = h;
+}
+
+/*
+ * Cache the CallerAccess result obtained from doing a fileserver operation
+ * that returned a vnode status for a particular key. If a callback break
+ * occurs whilst the operation was in progress then we have to ditch the cache
+ * as the ACL *may* have changed.
+ */
+void afs_cache_permit(struct afs_vnode *vnode, struct key *key,
+ unsigned int cb_break, struct afs_status_cb *scb)
+{
+ struct afs_permits *permits, *xpermits, *replacement, *zap, *new = NULL;
+ afs_access_t caller_access = scb->status.caller_access;
+ size_t size = 0;
+ bool changed = false;
+ int i, j;
+
+ _enter("{%llx:%llu},%x,%x",
+ vnode->fid.vid, vnode->fid.vnode, key_serial(key), caller_access);
+
+ rcu_read_lock();
+
+ /* Check for the common case first: We got back the same access as last
+ * time we tried and already have it recorded.
+ */
+ permits = rcu_dereference(vnode->permit_cache);
+ if (permits) {
+ if (!permits->invalidated) {
+ for (i = 0; i < permits->nr_permits; i++) {
+ if (permits->permits[i].key < key)
+ continue;
+ if (permits->permits[i].key > key)
+ break;
+ if (permits->permits[i].access != caller_access) {
+ changed = true;
+ break;
+ }
+
+ if (afs_cb_is_broken(cb_break, vnode)) {
+ changed = true;
+ break;
+ }
+
+ /* The cache is still good. */
+ rcu_read_unlock();
+ return;
+ }
+ }
+
+ changed |= permits->invalidated;
+ size = permits->nr_permits;
+
+ /* If this set of permits is now wrong, clear the permits
+ * pointer so that no one tries to use the stale information.
+ */
+ if (changed) {
+ spin_lock(&vnode->lock);
+ if (permits != rcu_access_pointer(vnode->permit_cache))
+ goto someone_else_changed_it_unlock;
+ RCU_INIT_POINTER(vnode->permit_cache, NULL);
+ spin_unlock(&vnode->lock);
+
+ afs_put_permits(permits);
+ permits = NULL;
+ size = 0;
+ }
+ }
+
+ if (afs_cb_is_broken(cb_break, vnode))
+ goto someone_else_changed_it;
+
+ /* We need a ref on any permits list we want to copy as we'll have to
+ * drop the lock to do memory allocation.
+ */
+ if (permits && !refcount_inc_not_zero(&permits->usage))
+ goto someone_else_changed_it;
+
+ rcu_read_unlock();
+
+ /* Speculatively create a new list with the revised permission set. We
+ * discard this if we find an extant match already in the hash, but
+ * it's easier to compare with memcmp this way.
+ *
+ * We fill in the key pointers at this time, but we don't get the refs
+ * yet.
+ */
+ size++;
+ new = kzalloc(struct_size(new, permits, size), GFP_NOFS);
+ if (!new)
+ goto out_put;
+
+ refcount_set(&new->usage, 1);
+ new->nr_permits = size;
+ i = j = 0;
+ if (permits) {
+ for (i = 0; i < permits->nr_permits; i++) {
+ if (j == i && permits->permits[i].key > key) {
+ new->permits[j].key = key;
+ new->permits[j].access = caller_access;
+ j++;
+ }
+ new->permits[j].key = permits->permits[i].key;
+ new->permits[j].access = permits->permits[i].access;
+ j++;
+ }
+ }
+
+ if (j == i) {
+ new->permits[j].key = key;
+ new->permits[j].access = caller_access;
+ }
+
+ afs_hash_permits(new);
+
+ /* Now see if the permit list we want is actually already available */
+ spin_lock(&afs_permits_lock);
+
+ hash_for_each_possible(afs_permits_cache, xpermits, hash_node, new->h) {
+ if (xpermits->h != new->h ||
+ xpermits->invalidated ||
+ xpermits->nr_permits != new->nr_permits ||
+ memcmp(xpermits->permits, new->permits,
+ new->nr_permits * sizeof(struct afs_permit)) != 0)
+ continue;
+
+ if (refcount_inc_not_zero(&xpermits->usage)) {
+ replacement = xpermits;
+ goto found;
+ }
+
+ break;
+ }
+
+ for (i = 0; i < new->nr_permits; i++)
+ key_get(new->permits[i].key);
+ hash_add_rcu(afs_permits_cache, &new->hash_node, new->h);
+ replacement = new;
+ new = NULL;
+
+found:
+ spin_unlock(&afs_permits_lock);
+
+ kfree(new);
+
+ rcu_read_lock();
+ spin_lock(&vnode->lock);
+ zap = rcu_access_pointer(vnode->permit_cache);
+ if (!afs_cb_is_broken(cb_break, vnode) && zap == permits)
+ rcu_assign_pointer(vnode->permit_cache, replacement);
+ else
+ zap = replacement;
+ spin_unlock(&vnode->lock);
+ rcu_read_unlock();
+ afs_put_permits(zap);
+out_put:
+ afs_put_permits(permits);
+ return;
+
+someone_else_changed_it_unlock:
+ spin_unlock(&vnode->lock);
+someone_else_changed_it:
+ /* Someone else changed the cache under us - don't recheck at this
+ * time.
+ */
+ rcu_read_unlock();
+ return;
+}
+
+static bool afs_check_permit_rcu(struct afs_vnode *vnode, struct key *key,
+ afs_access_t *_access)
+{
+ const struct afs_permits *permits;
+ int i;
+
+ _enter("{%llx:%llu},%x",
+ vnode->fid.vid, vnode->fid.vnode, key_serial(key));
+
+ /* check the permits to see if we've got one yet */
+ if (key == vnode->volume->cell->anonymous_key) {
+ *_access = vnode->status.anon_access;
+ _leave(" = t [anon %x]", *_access);
+ return true;
+ }
+
+ permits = rcu_dereference(vnode->permit_cache);
+ if (permits) {
+ for (i = 0; i < permits->nr_permits; i++) {
+ if (permits->permits[i].key < key)
+ continue;
+ if (permits->permits[i].key > key)
+ break;
+
+ *_access = permits->permits[i].access;
+ _leave(" = %u [perm %x]", !permits->invalidated, *_access);
+ return !permits->invalidated;
+ }
+ }
+
+ _leave(" = f");
+ return false;
+}
+
+/*
+ * check with the fileserver to see if the directory or parent directory is
+ * permitted to be accessed with this authorisation, and if so, what access it
+ * is granted
+ */
+int afs_check_permit(struct afs_vnode *vnode, struct key *key,
+ afs_access_t *_access)
+{
+ struct afs_permits *permits;
+ bool valid = false;
+ int i, ret;
+
+ _enter("{%llx:%llu},%x",
+ vnode->fid.vid, vnode->fid.vnode, key_serial(key));
+
+ /* check the permits to see if we've got one yet */
+ if (key == vnode->volume->cell->anonymous_key) {
+ _debug("anon");
+ *_access = vnode->status.anon_access;
+ valid = true;
+ } else {
+ rcu_read_lock();
+ permits = rcu_dereference(vnode->permit_cache);
+ if (permits) {
+ for (i = 0; i < permits->nr_permits; i++) {
+ if (permits->permits[i].key < key)
+ continue;
+ if (permits->permits[i].key > key)
+ break;
+
+ *_access = permits->permits[i].access;
+ valid = !permits->invalidated;
+ break;
+ }
+ }
+ rcu_read_unlock();
+ }
+
+ if (!valid) {
+ /* Check the status on the file we're actually interested in
+ * (the post-processing will cache the result).
+ */
+ _debug("no valid permit");
+
+ ret = afs_fetch_status(vnode, key, false, _access);
+ if (ret < 0) {
+ *_access = 0;
+ _leave(" = %d", ret);
+ return ret;
+ }
+ }
+
+ _leave(" = 0 [access %x]", *_access);
+ return 0;
+}
+
+/*
+ * check the permissions on an AFS file
+ * - AFS ACLs are attached to directories only, and a file is controlled by its
+ * parent directory's ACL
+ */
+int afs_permission(struct mnt_idmap *idmap, struct inode *inode,
+ int mask)
+{
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ afs_access_t access;
+ struct key *key;
+ int ret = 0;
+
+ _enter("{{%llx:%llu},%lx},%x,",
+ vnode->fid.vid, vnode->fid.vnode, vnode->flags, mask);
+
+ if (mask & MAY_NOT_BLOCK) {
+ key = afs_request_key_rcu(vnode->volume->cell);
+ if (IS_ERR(key))
+ return -ECHILD;
+
+ ret = -ECHILD;
+ if (!afs_check_validity(vnode) ||
+ !afs_check_permit_rcu(vnode, key, &access))
+ goto error;
+ } else {
+ key = afs_request_key(vnode->volume->cell);
+ if (IS_ERR(key)) {
+ _leave(" = %ld [key]", PTR_ERR(key));
+ return PTR_ERR(key);
+ }
+
+ ret = afs_validate(vnode, key);
+ if (ret < 0)
+ goto error;
+
+ /* check the permits to see if we've got one yet */
+ ret = afs_check_permit(vnode, key, &access);
+ if (ret < 0)
+ goto error;
+ }
+
+ /* interpret the access mask */
+ _debug("REQ %x ACC %x on %s",
+ mask, access, S_ISDIR(inode->i_mode) ? "dir" : "file");
+
+ ret = 0;
+ if (S_ISDIR(inode->i_mode)) {
+ if (mask & (MAY_EXEC | MAY_READ | MAY_CHDIR)) {
+ if (!(access & AFS_ACE_LOOKUP))
+ goto permission_denied;
+ }
+ if (mask & MAY_WRITE) {
+ if (!(access & (AFS_ACE_DELETE | /* rmdir, unlink, rename from */
+ AFS_ACE_INSERT))) /* create, mkdir, symlink, rename to */
+ goto permission_denied;
+ }
+ } else {
+ if (!(access & AFS_ACE_LOOKUP))
+ goto permission_denied;
+ if ((mask & MAY_EXEC) && !(inode->i_mode & S_IXUSR))
+ goto permission_denied;
+ if (mask & (MAY_EXEC | MAY_READ)) {
+ if (!(access & AFS_ACE_READ))
+ goto permission_denied;
+ if (!(inode->i_mode & S_IRUSR))
+ goto permission_denied;
+ } else if (mask & MAY_WRITE) {
+ if (!(access & AFS_ACE_WRITE))
+ goto permission_denied;
+ if (!(inode->i_mode & S_IWUSR))
+ goto permission_denied;
+ }
+ }
+
+ key_put(key);
+ _leave(" = %d", ret);
+ return ret;
+
+permission_denied:
+ ret = -EACCES;
+error:
+ key_put(key);
+ _leave(" = %d", ret);
+ return ret;
+}
+
+void __exit afs_clean_up_permit_cache(void)
+{
+ int i;
+
+ for (i = 0; i < HASH_SIZE(afs_permits_cache); i++)
+ WARN_ON_ONCE(!hlist_empty(&afs_permits_cache[i]));
+
+}