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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/verify.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/verify.c')
-rw-r--r-- | fs/verity/verify.c | 409 |
1 files changed, 409 insertions, 0 deletions
diff --git a/fs/verity/verify.c b/fs/verity/verify.c new file mode 100644 index 000000000..f50e3b5b5 --- /dev/null +++ b/fs/verity/verify.c @@ -0,0 +1,409 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Data verification functions, i.e. hooks for ->readahead() + * + * Copyright 2019 Google LLC + */ + +#include "fsverity_private.h" + +#include <crypto/hash.h> +#include <linux/bio.h> + +static struct workqueue_struct *fsverity_read_workqueue; + +static inline int cmp_hashes(const struct fsverity_info *vi, + const u8 *want_hash, const u8 *real_hash, + u64 data_pos, int level) +{ + const unsigned int hsize = vi->tree_params.digest_size; + + if (memcmp(want_hash, real_hash, hsize) == 0) + return 0; + + fsverity_err(vi->inode, + "FILE CORRUPTED! pos=%llu, level=%d, want_hash=%s:%*phN, real_hash=%s:%*phN", + data_pos, level, + vi->tree_params.hash_alg->name, hsize, want_hash, + vi->tree_params.hash_alg->name, hsize, real_hash); + return -EBADMSG; +} + +static bool data_is_zeroed(struct inode *inode, struct page *page, + unsigned int len, unsigned int offset) +{ + void *virt = kmap_local_page(page); + + if (memchr_inv(virt + offset, 0, len)) { + kunmap_local(virt); + fsverity_err(inode, + "FILE CORRUPTED! Data past EOF is not zeroed"); + return false; + } + kunmap_local(virt); + return true; +} + +/* + * Returns true if the hash block with index @hblock_idx in the tree, located in + * @hpage, has already been verified. + */ +static bool is_hash_block_verified(struct fsverity_info *vi, struct page *hpage, + unsigned long hblock_idx) +{ + bool verified; + unsigned int blocks_per_page; + unsigned int i; + + /* + * When the Merkle tree block size and page size are the same, then the + * ->hash_block_verified bitmap isn't allocated, and we use PG_checked + * to directly indicate whether the page's block has been verified. + * + * Using PG_checked also guarantees that we re-verify hash pages that + * get evicted and re-instantiated from the backing storage, as new + * pages always start out with PG_checked cleared. + */ + if (!vi->hash_block_verified) + return PageChecked(hpage); + + /* + * When the Merkle tree block size and page size differ, we use a bitmap + * to indicate whether each hash block has been verified. + * + * However, we still need to ensure that hash pages that get evicted and + * re-instantiated from the backing storage are re-verified. To do + * this, we use PG_checked again, but now it doesn't really mean + * "checked". Instead, now it just serves as an indicator for whether + * the hash page is newly instantiated or not. + * + * The first thread that sees PG_checked=0 must clear the corresponding + * bitmap bits, then set PG_checked=1. This requires a spinlock. To + * avoid having to take this spinlock in the common case of + * PG_checked=1, we start with an opportunistic lockless read. + */ + if (PageChecked(hpage)) { + /* + * A read memory barrier is needed here to give ACQUIRE + * semantics to the above PageChecked() test. + */ + smp_rmb(); + return test_bit(hblock_idx, vi->hash_block_verified); + } + spin_lock(&vi->hash_page_init_lock); + if (PageChecked(hpage)) { + verified = test_bit(hblock_idx, vi->hash_block_verified); + } else { + blocks_per_page = vi->tree_params.blocks_per_page; + hblock_idx = round_down(hblock_idx, blocks_per_page); + for (i = 0; i < blocks_per_page; i++) + clear_bit(hblock_idx + i, vi->hash_block_verified); + /* + * A write memory barrier is needed here to give RELEASE + * semantics to the below SetPageChecked() operation. + */ + smp_wmb(); + SetPageChecked(hpage); + verified = false; + } + spin_unlock(&vi->hash_page_init_lock); + return verified; +} + +/* + * Verify a single data block against the file's Merkle tree. + * + * In principle, we need to verify the entire path to the root node. However, + * for efficiency the filesystem may cache the hash blocks. Therefore we need + * only ascend the tree until an already-verified hash block is seen, and then + * verify the path to that block. + * + * Return: %true if the data block is valid, else %false. + */ +static bool +verify_data_block(struct inode *inode, struct fsverity_info *vi, + struct ahash_request *req, struct page *data_page, + u64 data_pos, unsigned int dblock_offset_in_page, + unsigned long max_ra_pages) +{ + const struct merkle_tree_params *params = &vi->tree_params; + const unsigned int hsize = params->digest_size; + int level; + u8 _want_hash[FS_VERITY_MAX_DIGEST_SIZE]; + const u8 *want_hash; + u8 real_hash[FS_VERITY_MAX_DIGEST_SIZE]; + /* The hash blocks that are traversed, indexed by level */ + struct { + /* Page containing the hash block */ + struct page *page; + /* Index of the hash block in the tree overall */ + unsigned long index; + /* Byte offset of the hash block within @page */ + unsigned int offset_in_page; + /* Byte offset of the wanted hash within @page */ + unsigned int hoffset; + } hblocks[FS_VERITY_MAX_LEVELS]; + /* + * The index of the previous level's block within that level; also the + * index of that block's hash within the current level. + */ + u64 hidx = data_pos >> params->log_blocksize; + int err; + + if (unlikely(data_pos >= inode->i_size)) { + /* + * This can happen in the data page spanning EOF when the Merkle + * tree block size is less than the page size. The Merkle tree + * doesn't cover data blocks fully past EOF. But the entire + * page spanning EOF can be visible to userspace via a mmap, and + * any part past EOF should be all zeroes. Therefore, we need + * to verify that any data blocks fully past EOF are all zeroes. + */ + return data_is_zeroed(inode, data_page, params->block_size, + dblock_offset_in_page); + } + + /* + * Starting at the leaf level, ascend the tree saving hash blocks along + * the way until we find a hash block that has already been verified, or + * until we reach the root. + */ + for (level = 0; level < params->num_levels; level++) { + unsigned long next_hidx; + unsigned long hblock_idx; + pgoff_t hpage_idx; + unsigned int hblock_offset_in_page; + unsigned int hoffset; + struct page *hpage; + + /* + * The index of the block in the current level; also the index + * of that block's hash within the next level. + */ + next_hidx = hidx >> params->log_arity; + + /* Index of the hash block in the tree overall */ + hblock_idx = params->level_start[level] + next_hidx; + + /* Index of the hash page in the tree overall */ + hpage_idx = hblock_idx >> params->log_blocks_per_page; + + /* Byte offset of the hash block within the page */ + hblock_offset_in_page = + (hblock_idx << params->log_blocksize) & ~PAGE_MASK; + + /* Byte offset of the hash within the page */ + hoffset = hblock_offset_in_page + + ((hidx << params->log_digestsize) & + (params->block_size - 1)); + + hpage = inode->i_sb->s_vop->read_merkle_tree_page(inode, + hpage_idx, level == 0 ? min(max_ra_pages, + params->tree_pages - hpage_idx) : 0); + if (IS_ERR(hpage)) { + err = PTR_ERR(hpage); + fsverity_err(inode, + "Error %d reading Merkle tree page %lu", + err, hpage_idx); + goto out; + } + if (is_hash_block_verified(vi, hpage, hblock_idx)) { + memcpy_from_page(_want_hash, hpage, hoffset, hsize); + want_hash = _want_hash; + put_page(hpage); + goto descend; + } + hblocks[level].page = hpage; + hblocks[level].index = hblock_idx; + hblocks[level].offset_in_page = hblock_offset_in_page; + hblocks[level].hoffset = hoffset; + hidx = next_hidx; + } + + want_hash = vi->root_hash; +descend: + /* Descend the tree verifying hash blocks. */ + for (; level > 0; level--) { + struct page *hpage = hblocks[level - 1].page; + unsigned long hblock_idx = hblocks[level - 1].index; + unsigned int hblock_offset_in_page = + hblocks[level - 1].offset_in_page; + unsigned int hoffset = hblocks[level - 1].hoffset; + + err = fsverity_hash_block(params, inode, req, hpage, + hblock_offset_in_page, real_hash); + if (err) + goto out; + err = cmp_hashes(vi, want_hash, real_hash, data_pos, level - 1); + if (err) + goto out; + /* + * Mark the hash block as verified. This must be atomic and + * idempotent, as the same hash block might be verified by + * multiple threads concurrently. + */ + if (vi->hash_block_verified) + set_bit(hblock_idx, vi->hash_block_verified); + else + SetPageChecked(hpage); + memcpy_from_page(_want_hash, hpage, hoffset, hsize); + want_hash = _want_hash; + put_page(hpage); + } + + /* Finally, verify the data block. */ + err = fsverity_hash_block(params, inode, req, data_page, + dblock_offset_in_page, real_hash); + if (err) + goto out; + err = cmp_hashes(vi, want_hash, real_hash, data_pos, -1); +out: + for (; level > 0; level--) + put_page(hblocks[level - 1].page); + + return err == 0; +} + +static bool +verify_data_blocks(struct inode *inode, struct fsverity_info *vi, + struct ahash_request *req, struct folio *data_folio, + size_t len, size_t offset, unsigned long max_ra_pages) +{ + const unsigned int block_size = vi->tree_params.block_size; + u64 pos = (u64)data_folio->index << PAGE_SHIFT; + + if (WARN_ON_ONCE(len <= 0 || !IS_ALIGNED(len | offset, block_size))) + return false; + if (WARN_ON_ONCE(!folio_test_locked(data_folio) || + folio_test_uptodate(data_folio))) + return false; + do { + struct page *data_page = + folio_page(data_folio, offset >> PAGE_SHIFT); + + if (!verify_data_block(inode, vi, req, data_page, pos + offset, + offset & ~PAGE_MASK, max_ra_pages)) + return false; + offset += block_size; + len -= block_size; + } while (len); + return true; +} + +/** + * fsverity_verify_blocks() - verify data in a folio + * @folio: the folio containing the data to verify + * @len: the length of the data to verify in the folio + * @offset: the offset of the data to verify in the folio + * + * Verify data that has just been read from a verity file. The data must be + * located in a pagecache folio that is still locked and not yet uptodate. The + * length and offset of the data must be Merkle tree block size aligned. + * + * Return: %true if the data is valid, else %false. + */ +bool fsverity_verify_blocks(struct folio *folio, size_t len, size_t offset) +{ + struct inode *inode = folio->mapping->host; + struct fsverity_info *vi = inode->i_verity_info; + struct ahash_request *req; + bool valid; + + /* This allocation never fails, since it's mempool-backed. */ + req = fsverity_alloc_hash_request(vi->tree_params.hash_alg, GFP_NOFS); + + valid = verify_data_blocks(inode, vi, req, folio, len, offset, 0); + + fsverity_free_hash_request(vi->tree_params.hash_alg, req); + + return valid; +} +EXPORT_SYMBOL_GPL(fsverity_verify_blocks); + +#ifdef CONFIG_BLOCK +/** + * fsverity_verify_bio() - verify a 'read' bio that has just completed + * @bio: the bio to verify + * + * Verify the bio's data against the file's Merkle tree. All bio data segments + * must be aligned to the file's Merkle tree block size. If any data fails + * verification, then bio->bi_status is set to an error status. + * + * This is a helper function for use by the ->readahead() method of filesystems + * that issue bios to read data directly into the page cache. Filesystems that + * populate the page cache without issuing bios (e.g. non block-based + * filesystems) must instead call fsverity_verify_page() directly on each page. + * All filesystems must also call fsverity_verify_page() on holes. + */ +void fsverity_verify_bio(struct bio *bio) +{ + struct inode *inode = bio_first_page_all(bio)->mapping->host; + struct fsverity_info *vi = inode->i_verity_info; + struct ahash_request *req; + struct folio_iter fi; + unsigned long max_ra_pages = 0; + + /* This allocation never fails, since it's mempool-backed. */ + req = fsverity_alloc_hash_request(vi->tree_params.hash_alg, GFP_NOFS); + + if (bio->bi_opf & REQ_RAHEAD) { + /* + * If this bio is for data readahead, then we also do readahead + * of the first (largest) level of the Merkle tree. Namely, + * when a Merkle tree page is read, we also try to piggy-back on + * some additional pages -- up to 1/4 the number of data pages. + * + * This improves sequential read performance, as it greatly + * reduces the number of I/O requests made to the Merkle tree. + */ + max_ra_pages = bio->bi_iter.bi_size >> (PAGE_SHIFT + 2); + } + + bio_for_each_folio_all(fi, bio) { + if (!verify_data_blocks(inode, vi, req, fi.folio, fi.length, + fi.offset, max_ra_pages)) { + bio->bi_status = BLK_STS_IOERR; + break; + } + } + + fsverity_free_hash_request(vi->tree_params.hash_alg, req); +} +EXPORT_SYMBOL_GPL(fsverity_verify_bio); +#endif /* CONFIG_BLOCK */ + +/** + * fsverity_enqueue_verify_work() - enqueue work on the fs-verity workqueue + * @work: the work to enqueue + * + * Enqueue verification work for asynchronous processing. + */ +void fsverity_enqueue_verify_work(struct work_struct *work) +{ + queue_work(fsverity_read_workqueue, work); +} +EXPORT_SYMBOL_GPL(fsverity_enqueue_verify_work); + +int __init fsverity_init_workqueue(void) +{ + /* + * Use an unbound workqueue to allow bios to be verified in parallel + * even when they happen to complete on the same CPU. This sacrifices + * locality, but it's worthwhile since hashing is CPU-intensive. + * + * Also use a high-priority workqueue to prioritize verification work, + * which blocks reads from completing, over regular application tasks. + */ + fsverity_read_workqueue = alloc_workqueue("fsverity_read_queue", + WQ_UNBOUND | WQ_HIGHPRI, + num_online_cpus()); + if (!fsverity_read_workqueue) + return -ENOMEM; + return 0; +} + +void __init fsverity_exit_workqueue(void) +{ + destroy_workqueue(fsverity_read_workqueue); + fsverity_read_workqueue = NULL; +} |