diff options
author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /fs/verity/open.c | |
download | linux-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/verity/open.c')
-rw-r--r-- | fs/verity/open.c | 425 |
1 files changed, 425 insertions, 0 deletions
diff --git a/fs/verity/open.c b/fs/verity/open.c new file mode 100644 index 000000000..9366b441d --- /dev/null +++ b/fs/verity/open.c @@ -0,0 +1,425 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Opening fs-verity files + * + * Copyright 2019 Google LLC + */ + +#include "fsverity_private.h" + +#include <linux/mm.h> +#include <linux/slab.h> + +static struct kmem_cache *fsverity_info_cachep; + +/** + * fsverity_init_merkle_tree_params() - initialize Merkle tree parameters + * @params: the parameters struct to initialize + * @inode: the inode for which the Merkle tree is being built + * @hash_algorithm: number of hash algorithm to use + * @log_blocksize: log base 2 of block size to use + * @salt: pointer to salt (optional) + * @salt_size: size of salt, possibly 0 + * + * Validate the hash algorithm and block size, then compute the tree topology + * (num levels, num blocks in each level, etc.) and initialize @params. + * + * Return: 0 on success, -errno on failure + */ +int fsverity_init_merkle_tree_params(struct merkle_tree_params *params, + const struct inode *inode, + unsigned int hash_algorithm, + unsigned int log_blocksize, + const u8 *salt, size_t salt_size) +{ + struct fsverity_hash_alg *hash_alg; + int err; + u64 blocks; + u64 blocks_in_level[FS_VERITY_MAX_LEVELS]; + u64 offset; + int level; + + memset(params, 0, sizeof(*params)); + + hash_alg = fsverity_get_hash_alg(inode, hash_algorithm); + if (IS_ERR(hash_alg)) + return PTR_ERR(hash_alg); + params->hash_alg = hash_alg; + params->digest_size = hash_alg->digest_size; + + params->hashstate = fsverity_prepare_hash_state(hash_alg, salt, + salt_size); + if (IS_ERR(params->hashstate)) { + err = PTR_ERR(params->hashstate); + params->hashstate = NULL; + fsverity_err(inode, "Error %d preparing hash state", err); + goto out_err; + } + + /* + * fs/verity/ directly assumes that the Merkle tree block size is a + * power of 2 less than or equal to PAGE_SIZE. Another restriction + * arises from the interaction between fs/verity/ and the filesystems + * themselves: filesystems expect to be able to verify a single + * filesystem block of data at a time. Therefore, the Merkle tree block + * size must also be less than or equal to the filesystem block size. + * + * The above are the only hard limitations, so in theory the Merkle tree + * block size could be as small as twice the digest size. However, + * that's not useful, and it would result in some unusually deep and + * large Merkle trees. So we currently require that the Merkle tree + * block size be at least 1024 bytes. That's small enough to test the + * sub-page block case on systems with 4K pages, but not too small. + */ + if (log_blocksize < 10 || log_blocksize > PAGE_SHIFT || + log_blocksize > inode->i_blkbits) { + fsverity_warn(inode, "Unsupported log_blocksize: %u", + log_blocksize); + err = -EINVAL; + goto out_err; + } + params->log_blocksize = log_blocksize; + params->block_size = 1 << log_blocksize; + params->log_blocks_per_page = PAGE_SHIFT - log_blocksize; + params->blocks_per_page = 1 << params->log_blocks_per_page; + + if (WARN_ON(!is_power_of_2(params->digest_size))) { + err = -EINVAL; + goto out_err; + } + if (params->block_size < 2 * params->digest_size) { + fsverity_warn(inode, + "Merkle tree block size (%u) too small for hash algorithm \"%s\"", + params->block_size, hash_alg->name); + err = -EINVAL; + goto out_err; + } + params->log_digestsize = ilog2(params->digest_size); + params->log_arity = log_blocksize - params->log_digestsize; + params->hashes_per_block = 1 << params->log_arity; + + /* + * Compute the number of levels in the Merkle tree and create a map from + * level to the starting block of that level. Level 'num_levels - 1' is + * the root and is stored first. Level 0 is the level directly "above" + * the data blocks and is stored last. + */ + + /* Compute number of levels and the number of blocks in each level */ + blocks = ((u64)inode->i_size + params->block_size - 1) >> log_blocksize; + while (blocks > 1) { + if (params->num_levels >= FS_VERITY_MAX_LEVELS) { + fsverity_err(inode, "Too many levels in Merkle tree"); + err = -EFBIG; + goto out_err; + } + blocks = (blocks + params->hashes_per_block - 1) >> + params->log_arity; + blocks_in_level[params->num_levels++] = blocks; + } + + /* Compute the starting block of each level */ + offset = 0; + for (level = (int)params->num_levels - 1; level >= 0; level--) { + params->level_start[level] = offset; + offset += blocks_in_level[level]; + } + + /* + * With block_size != PAGE_SIZE, an in-memory bitmap will need to be + * allocated to track the "verified" status of hash blocks. Don't allow + * this bitmap to get too large. For now, limit it to 1 MiB, which + * limits the file size to about 4.4 TB with SHA-256 and 4K blocks. + * + * Together with the fact that the data, and thus also the Merkle tree, + * cannot have more than ULONG_MAX pages, this implies that hash block + * indices can always fit in an 'unsigned long'. But to be safe, we + * explicitly check for that too. Note, this is only for hash block + * indices; data block indices might not fit in an 'unsigned long'. + */ + if ((params->block_size != PAGE_SIZE && offset > 1 << 23) || + offset > ULONG_MAX) { + fsverity_err(inode, "Too many blocks in Merkle tree"); + err = -EFBIG; + goto out_err; + } + + params->tree_size = offset << log_blocksize; + params->tree_pages = PAGE_ALIGN(params->tree_size) >> PAGE_SHIFT; + return 0; + +out_err: + kfree(params->hashstate); + memset(params, 0, sizeof(*params)); + return err; +} + +/* + * Compute the file digest by hashing the fsverity_descriptor excluding the + * signature and with the sig_size field set to 0. + */ +static int compute_file_digest(struct fsverity_hash_alg *hash_alg, + struct fsverity_descriptor *desc, + u8 *file_digest) +{ + __le32 sig_size = desc->sig_size; + int err; + + desc->sig_size = 0; + err = fsverity_hash_buffer(hash_alg, desc, sizeof(*desc), file_digest); + desc->sig_size = sig_size; + + return err; +} + +/* + * Create a new fsverity_info from the given fsverity_descriptor (with optional + * appended signature), and check the signature if present. The + * fsverity_descriptor must have already undergone basic validation. + */ +struct fsverity_info *fsverity_create_info(const struct inode *inode, + struct fsverity_descriptor *desc) +{ + struct fsverity_info *vi; + int err; + + vi = kmem_cache_zalloc(fsverity_info_cachep, GFP_KERNEL); + if (!vi) + return ERR_PTR(-ENOMEM); + vi->inode = inode; + + err = fsverity_init_merkle_tree_params(&vi->tree_params, inode, + desc->hash_algorithm, + desc->log_blocksize, + desc->salt, desc->salt_size); + if (err) { + fsverity_err(inode, + "Error %d initializing Merkle tree parameters", + err); + goto fail; + } + + memcpy(vi->root_hash, desc->root_hash, vi->tree_params.digest_size); + + err = compute_file_digest(vi->tree_params.hash_alg, desc, + vi->file_digest); + if (err) { + fsverity_err(inode, "Error %d computing file digest", err); + goto fail; + } + + err = fsverity_verify_signature(vi, desc->signature, + le32_to_cpu(desc->sig_size)); + if (err) + goto fail; + + if (vi->tree_params.block_size != PAGE_SIZE) { + /* + * When the Merkle tree block size and page size differ, we use + * a bitmap to keep track of which hash blocks have been + * verified. This bitmap must contain one bit per hash block, + * including alignment to a page boundary at the end. + * + * Eventually, to support extremely large files in an efficient + * way, it might be necessary to make pages of this bitmap + * reclaimable. But for now, simply allocating the whole bitmap + * is a simple solution that works well on the files on which + * fsverity is realistically used. E.g., with SHA-256 and 4K + * blocks, a 100MB file only needs a 24-byte bitmap, and the + * bitmap for any file under 17GB fits in a 4K page. + */ + unsigned long num_bits = + vi->tree_params.tree_pages << + vi->tree_params.log_blocks_per_page; + + vi->hash_block_verified = kvcalloc(BITS_TO_LONGS(num_bits), + sizeof(unsigned long), + GFP_KERNEL); + if (!vi->hash_block_verified) { + err = -ENOMEM; + goto fail; + } + spin_lock_init(&vi->hash_page_init_lock); + } + + return vi; + +fail: + fsverity_free_info(vi); + return ERR_PTR(err); +} + +void fsverity_set_info(struct inode *inode, struct fsverity_info *vi) +{ + /* + * Multiple tasks may race to set ->i_verity_info, so use + * cmpxchg_release(). This pairs with the smp_load_acquire() in + * fsverity_get_info(). I.e., here we publish ->i_verity_info with a + * RELEASE barrier so that other tasks can ACQUIRE it. + */ + if (cmpxchg_release(&inode->i_verity_info, NULL, vi) != NULL) { + /* Lost the race, so free the fsverity_info we allocated. */ + fsverity_free_info(vi); + /* + * Afterwards, the caller may access ->i_verity_info directly, + * so make sure to ACQUIRE the winning fsverity_info. + */ + (void)fsverity_get_info(inode); + } +} + +void fsverity_free_info(struct fsverity_info *vi) +{ + if (!vi) + return; + kfree(vi->tree_params.hashstate); + kvfree(vi->hash_block_verified); + kmem_cache_free(fsverity_info_cachep, vi); +} + +static bool validate_fsverity_descriptor(struct inode *inode, + const struct fsverity_descriptor *desc, + size_t desc_size) +{ + if (desc_size < sizeof(*desc)) { + fsverity_err(inode, "Unrecognized descriptor size: %zu bytes", + desc_size); + return false; + } + + if (desc->version != 1) { + fsverity_err(inode, "Unrecognized descriptor version: %u", + desc->version); + return false; + } + + if (memchr_inv(desc->__reserved, 0, sizeof(desc->__reserved))) { + fsverity_err(inode, "Reserved bits set in descriptor"); + return false; + } + + if (desc->salt_size > sizeof(desc->salt)) { + fsverity_err(inode, "Invalid salt_size: %u", desc->salt_size); + return false; + } + + if (le64_to_cpu(desc->data_size) != inode->i_size) { + fsverity_err(inode, + "Wrong data_size: %llu (desc) != %lld (inode)", + le64_to_cpu(desc->data_size), inode->i_size); + return false; + } + + if (le32_to_cpu(desc->sig_size) > desc_size - sizeof(*desc)) { + fsverity_err(inode, "Signature overflows verity descriptor"); + return false; + } + + return true; +} + +/* + * Read the inode's fsverity_descriptor (with optional appended signature) from + * the filesystem, and do basic validation of it. + */ +int fsverity_get_descriptor(struct inode *inode, + struct fsverity_descriptor **desc_ret) +{ + int res; + struct fsverity_descriptor *desc; + + res = inode->i_sb->s_vop->get_verity_descriptor(inode, NULL, 0); + if (res < 0) { + fsverity_err(inode, + "Error %d getting verity descriptor size", res); + return res; + } + if (res > FS_VERITY_MAX_DESCRIPTOR_SIZE) { + fsverity_err(inode, "Verity descriptor is too large (%d bytes)", + res); + return -EMSGSIZE; + } + desc = kmalloc(res, GFP_KERNEL); + if (!desc) + return -ENOMEM; + res = inode->i_sb->s_vop->get_verity_descriptor(inode, desc, res); + if (res < 0) { + fsverity_err(inode, "Error %d reading verity descriptor", res); + kfree(desc); + return res; + } + + if (!validate_fsverity_descriptor(inode, desc, res)) { + kfree(desc); + return -EINVAL; + } + + *desc_ret = desc; + return 0; +} + +/* Ensure the inode has an ->i_verity_info */ +static int ensure_verity_info(struct inode *inode) +{ + struct fsverity_info *vi = fsverity_get_info(inode); + struct fsverity_descriptor *desc; + int err; + + if (vi) + return 0; + + err = fsverity_get_descriptor(inode, &desc); + if (err) + return err; + + vi = fsverity_create_info(inode, desc); + if (IS_ERR(vi)) { + err = PTR_ERR(vi); + goto out_free_desc; + } + + fsverity_set_info(inode, vi); + err = 0; +out_free_desc: + kfree(desc); + return err; +} + +int __fsverity_file_open(struct inode *inode, struct file *filp) +{ + if (filp->f_mode & FMODE_WRITE) + return -EPERM; + return ensure_verity_info(inode); +} +EXPORT_SYMBOL_GPL(__fsverity_file_open); + +int __fsverity_prepare_setattr(struct dentry *dentry, struct iattr *attr) +{ + if (attr->ia_valid & ATTR_SIZE) + return -EPERM; + return 0; +} +EXPORT_SYMBOL_GPL(__fsverity_prepare_setattr); + +void __fsverity_cleanup_inode(struct inode *inode) +{ + fsverity_free_info(inode->i_verity_info); + inode->i_verity_info = NULL; +} +EXPORT_SYMBOL_GPL(__fsverity_cleanup_inode); + +int __init fsverity_init_info_cache(void) +{ + fsverity_info_cachep = KMEM_CACHE_USERCOPY(fsverity_info, + SLAB_RECLAIM_ACCOUNT, + file_digest); + if (!fsverity_info_cachep) + return -ENOMEM; + return 0; +} + +void __init fsverity_exit_info_cache(void) +{ + kmem_cache_destroy(fsverity_info_cachep); + fsverity_info_cachep = NULL; +} |