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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 /fs/crypto/keysetup_v1.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 'fs/crypto/keysetup_v1.c')
-rw-r--r--fs/crypto/keysetup_v1.c321
1 files changed, 321 insertions, 0 deletions
diff --git a/fs/crypto/keysetup_v1.c b/fs/crypto/keysetup_v1.c
new file mode 100644
index 000000000..75dabd9b2
--- /dev/null
+++ b/fs/crypto/keysetup_v1.c
@@ -0,0 +1,321 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Key setup for v1 encryption policies
+ *
+ * Copyright 2015, 2019 Google LLC
+ */
+
+/*
+ * This file implements compatibility functions for the original encryption
+ * policy version ("v1"), including:
+ *
+ * - Deriving per-file encryption keys using the AES-128-ECB based KDF
+ * (rather than the new method of using HKDF-SHA512)
+ *
+ * - Retrieving fscrypt master keys from process-subscribed keyrings
+ * (rather than the new method of using a filesystem-level keyring)
+ *
+ * - Handling policies with the DIRECT_KEY flag set using a master key table
+ * (rather than the new method of implementing DIRECT_KEY with per-mode keys
+ * managed alongside the master keys in the filesystem-level keyring)
+ */
+
+#include <crypto/algapi.h>
+#include <crypto/skcipher.h>
+#include <keys/user-type.h>
+#include <linux/hashtable.h>
+#include <linux/scatterlist.h>
+
+#include "fscrypt_private.h"
+
+/* Table of keys referenced by DIRECT_KEY policies */
+static DEFINE_HASHTABLE(fscrypt_direct_keys, 6); /* 6 bits = 64 buckets */
+static DEFINE_SPINLOCK(fscrypt_direct_keys_lock);
+
+/*
+ * v1 key derivation function. This generates the derived key by encrypting the
+ * master key with AES-128-ECB using the nonce as the AES key. This provides a
+ * unique derived key with sufficient entropy for each inode. However, it's
+ * nonstandard, non-extensible, doesn't evenly distribute the entropy from the
+ * master key, and is trivially reversible: an attacker who compromises a
+ * derived key can "decrypt" it to get back to the master key, then derive any
+ * other key. For all new code, use HKDF instead.
+ *
+ * The master key must be at least as long as the derived key. If the master
+ * key is longer, then only the first 'derived_keysize' bytes are used.
+ */
+static int derive_key_aes(const u8 *master_key,
+ const u8 nonce[FSCRYPT_FILE_NONCE_SIZE],
+ u8 *derived_key, unsigned int derived_keysize)
+{
+ int res = 0;
+ struct skcipher_request *req = NULL;
+ DECLARE_CRYPTO_WAIT(wait);
+ struct scatterlist src_sg, dst_sg;
+ struct crypto_skcipher *tfm = crypto_alloc_skcipher("ecb(aes)", 0, 0);
+
+ if (IS_ERR(tfm)) {
+ res = PTR_ERR(tfm);
+ tfm = NULL;
+ goto out;
+ }
+ crypto_skcipher_set_flags(tfm, CRYPTO_TFM_REQ_FORBID_WEAK_KEYS);
+ req = skcipher_request_alloc(tfm, GFP_KERNEL);
+ if (!req) {
+ res = -ENOMEM;
+ goto out;
+ }
+ skcipher_request_set_callback(req,
+ CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
+ crypto_req_done, &wait);
+ res = crypto_skcipher_setkey(tfm, nonce, FSCRYPT_FILE_NONCE_SIZE);
+ if (res < 0)
+ goto out;
+
+ sg_init_one(&src_sg, master_key, derived_keysize);
+ sg_init_one(&dst_sg, derived_key, derived_keysize);
+ skcipher_request_set_crypt(req, &src_sg, &dst_sg, derived_keysize,
+ NULL);
+ res = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
+out:
+ skcipher_request_free(req);
+ crypto_free_skcipher(tfm);
+ return res;
+}
+
+/*
+ * Search the current task's subscribed keyrings for a "logon" key with
+ * description prefix:descriptor, and if found acquire a read lock on it and
+ * return a pointer to its validated payload in *payload_ret.
+ */
+static struct key *
+find_and_lock_process_key(const char *prefix,
+ const u8 descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE],
+ unsigned int min_keysize,
+ const struct fscrypt_key **payload_ret)
+{
+ char *description;
+ struct key *key;
+ const struct user_key_payload *ukp;
+ const struct fscrypt_key *payload;
+
+ description = kasprintf(GFP_KERNEL, "%s%*phN", prefix,
+ FSCRYPT_KEY_DESCRIPTOR_SIZE, descriptor);
+ if (!description)
+ return ERR_PTR(-ENOMEM);
+
+ key = request_key(&key_type_logon, description, NULL);
+ kfree(description);
+ if (IS_ERR(key))
+ return key;
+
+ down_read(&key->sem);
+ ukp = user_key_payload_locked(key);
+
+ if (!ukp) /* was the key revoked before we acquired its semaphore? */
+ goto invalid;
+
+ payload = (const struct fscrypt_key *)ukp->data;
+
+ if (ukp->datalen != sizeof(struct fscrypt_key) ||
+ payload->size < 1 || payload->size > FSCRYPT_MAX_KEY_SIZE) {
+ fscrypt_warn(NULL,
+ "key with description '%s' has invalid payload",
+ key->description);
+ goto invalid;
+ }
+
+ if (payload->size < min_keysize) {
+ fscrypt_warn(NULL,
+ "key with description '%s' is too short (got %u bytes, need %u+ bytes)",
+ key->description, payload->size, min_keysize);
+ goto invalid;
+ }
+
+ *payload_ret = payload;
+ return key;
+
+invalid:
+ up_read(&key->sem);
+ key_put(key);
+ return ERR_PTR(-ENOKEY);
+}
+
+/* Master key referenced by DIRECT_KEY policy */
+struct fscrypt_direct_key {
+ struct super_block *dk_sb;
+ struct hlist_node dk_node;
+ refcount_t dk_refcount;
+ const struct fscrypt_mode *dk_mode;
+ struct fscrypt_prepared_key dk_key;
+ u8 dk_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
+ u8 dk_raw[FSCRYPT_MAX_KEY_SIZE];
+};
+
+static void free_direct_key(struct fscrypt_direct_key *dk)
+{
+ if (dk) {
+ fscrypt_destroy_prepared_key(dk->dk_sb, &dk->dk_key);
+ kfree_sensitive(dk);
+ }
+}
+
+void fscrypt_put_direct_key(struct fscrypt_direct_key *dk)
+{
+ if (!refcount_dec_and_lock(&dk->dk_refcount, &fscrypt_direct_keys_lock))
+ return;
+ hash_del(&dk->dk_node);
+ spin_unlock(&fscrypt_direct_keys_lock);
+
+ free_direct_key(dk);
+}
+
+/*
+ * Find/insert the given key into the fscrypt_direct_keys table. If found, it
+ * is returned with elevated refcount, and 'to_insert' is freed if non-NULL. If
+ * not found, 'to_insert' is inserted and returned if it's non-NULL; otherwise
+ * NULL is returned.
+ */
+static struct fscrypt_direct_key *
+find_or_insert_direct_key(struct fscrypt_direct_key *to_insert,
+ const u8 *raw_key, const struct fscrypt_info *ci)
+{
+ unsigned long hash_key;
+ struct fscrypt_direct_key *dk;
+
+ /*
+ * Careful: to avoid potentially leaking secret key bytes via timing
+ * information, we must key the hash table by descriptor rather than by
+ * raw key, and use crypto_memneq() when comparing raw keys.
+ */
+
+ BUILD_BUG_ON(sizeof(hash_key) > FSCRYPT_KEY_DESCRIPTOR_SIZE);
+ memcpy(&hash_key, ci->ci_policy.v1.master_key_descriptor,
+ sizeof(hash_key));
+
+ spin_lock(&fscrypt_direct_keys_lock);
+ hash_for_each_possible(fscrypt_direct_keys, dk, dk_node, hash_key) {
+ if (memcmp(ci->ci_policy.v1.master_key_descriptor,
+ dk->dk_descriptor, FSCRYPT_KEY_DESCRIPTOR_SIZE) != 0)
+ continue;
+ if (ci->ci_mode != dk->dk_mode)
+ continue;
+ if (!fscrypt_is_key_prepared(&dk->dk_key, ci))
+ continue;
+ if (crypto_memneq(raw_key, dk->dk_raw, ci->ci_mode->keysize))
+ continue;
+ /* using existing tfm with same (descriptor, mode, raw_key) */
+ refcount_inc(&dk->dk_refcount);
+ spin_unlock(&fscrypt_direct_keys_lock);
+ free_direct_key(to_insert);
+ return dk;
+ }
+ if (to_insert)
+ hash_add(fscrypt_direct_keys, &to_insert->dk_node, hash_key);
+ spin_unlock(&fscrypt_direct_keys_lock);
+ return to_insert;
+}
+
+/* Prepare to encrypt directly using the master key in the given mode */
+static struct fscrypt_direct_key *
+fscrypt_get_direct_key(const struct fscrypt_info *ci, const u8 *raw_key)
+{
+ struct fscrypt_direct_key *dk;
+ int err;
+
+ /* Is there already a tfm for this key? */
+ dk = find_or_insert_direct_key(NULL, raw_key, ci);
+ if (dk)
+ return dk;
+
+ /* Nope, allocate one. */
+ dk = kzalloc(sizeof(*dk), GFP_KERNEL);
+ if (!dk)
+ return ERR_PTR(-ENOMEM);
+ dk->dk_sb = ci->ci_inode->i_sb;
+ refcount_set(&dk->dk_refcount, 1);
+ dk->dk_mode = ci->ci_mode;
+ err = fscrypt_prepare_key(&dk->dk_key, raw_key, ci);
+ if (err)
+ goto err_free_dk;
+ memcpy(dk->dk_descriptor, ci->ci_policy.v1.master_key_descriptor,
+ FSCRYPT_KEY_DESCRIPTOR_SIZE);
+ memcpy(dk->dk_raw, raw_key, ci->ci_mode->keysize);
+
+ return find_or_insert_direct_key(dk, raw_key, ci);
+
+err_free_dk:
+ free_direct_key(dk);
+ return ERR_PTR(err);
+}
+
+/* v1 policy, DIRECT_KEY: use the master key directly */
+static int setup_v1_file_key_direct(struct fscrypt_info *ci,
+ const u8 *raw_master_key)
+{
+ struct fscrypt_direct_key *dk;
+
+ dk = fscrypt_get_direct_key(ci, raw_master_key);
+ if (IS_ERR(dk))
+ return PTR_ERR(dk);
+ ci->ci_direct_key = dk;
+ ci->ci_enc_key = dk->dk_key;
+ return 0;
+}
+
+/* v1 policy, !DIRECT_KEY: derive the file's encryption key */
+static int setup_v1_file_key_derived(struct fscrypt_info *ci,
+ const u8 *raw_master_key)
+{
+ u8 *derived_key;
+ int err;
+
+ /*
+ * This cannot be a stack buffer because it will be passed to the
+ * scatterlist crypto API during derive_key_aes().
+ */
+ derived_key = kmalloc(ci->ci_mode->keysize, GFP_KERNEL);
+ if (!derived_key)
+ return -ENOMEM;
+
+ err = derive_key_aes(raw_master_key, ci->ci_nonce,
+ derived_key, ci->ci_mode->keysize);
+ if (err)
+ goto out;
+
+ err = fscrypt_set_per_file_enc_key(ci, derived_key);
+out:
+ kfree_sensitive(derived_key);
+ return err;
+}
+
+int fscrypt_setup_v1_file_key(struct fscrypt_info *ci, const u8 *raw_master_key)
+{
+ if (ci->ci_policy.v1.flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY)
+ return setup_v1_file_key_direct(ci, raw_master_key);
+ else
+ return setup_v1_file_key_derived(ci, raw_master_key);
+}
+
+int fscrypt_setup_v1_file_key_via_subscribed_keyrings(struct fscrypt_info *ci)
+{
+ struct key *key;
+ const struct fscrypt_key *payload;
+ int err;
+
+ key = find_and_lock_process_key(FSCRYPT_KEY_DESC_PREFIX,
+ ci->ci_policy.v1.master_key_descriptor,
+ ci->ci_mode->keysize, &payload);
+ if (key == ERR_PTR(-ENOKEY) && ci->ci_inode->i_sb->s_cop->key_prefix) {
+ key = find_and_lock_process_key(ci->ci_inode->i_sb->s_cop->key_prefix,
+ ci->ci_policy.v1.master_key_descriptor,
+ ci->ci_mode->keysize, &payload);
+ }
+ if (IS_ERR(key))
+ return PTR_ERR(key);
+
+ err = fscrypt_setup_v1_file_key(ci, payload->raw);
+ up_read(&key->sem);
+ key_put(key);
+ return err;
+}