From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 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(). ... --- fs/mnt_idmapping.c | 273 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 273 insertions(+) create mode 100644 fs/mnt_idmapping.c (limited to 'fs/mnt_idmapping.c') diff --git a/fs/mnt_idmapping.c b/fs/mnt_idmapping.c new file mode 100644 index 000000000..4905665c4 --- /dev/null +++ b/fs/mnt_idmapping.c @@ -0,0 +1,273 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Christian Brauner */ + +#include +#include +#include +#include +#include + +#include "internal.h" + +struct mnt_idmap { + struct user_namespace *owner; + refcount_t count; +}; + +/* + * Carries the initial idmapping of 0:0:4294967295 which is an identity + * mapping. This means that {g,u}id 0 is mapped to {g,u}id 0, {g,u}id 1 is + * mapped to {g,u}id 1, [...], {g,u}id 1000 to {g,u}id 1000, [...]. + */ +struct mnt_idmap nop_mnt_idmap = { + .owner = &init_user_ns, + .count = REFCOUNT_INIT(1), +}; +EXPORT_SYMBOL_GPL(nop_mnt_idmap); + +/** + * check_fsmapping - check whether an mount idmapping is allowed + * @idmap: idmap of the relevent mount + * @sb: super block of the filesystem + * + * Return: true if @idmap is allowed, false if not. + */ +bool check_fsmapping(const struct mnt_idmap *idmap, + const struct super_block *sb) +{ + return idmap->owner != sb->s_user_ns; +} + +/** + * initial_idmapping - check whether this is the initial mapping + * @ns: idmapping to check + * + * Check whether this is the initial mapping, mapping 0 to 0, 1 to 1, + * [...], 1000 to 1000 [...]. + * + * Return: true if this is the initial mapping, false if not. + */ +static inline bool initial_idmapping(const struct user_namespace *ns) +{ + return ns == &init_user_ns; +} + +/** + * no_idmapping - check whether we can skip remapping a kuid/gid + * @mnt_userns: the mount's idmapping + * @fs_userns: the filesystem's idmapping + * + * This function can be used to check whether a remapping between two + * idmappings is required. + * An idmapped mount is a mount that has an idmapping attached to it that + * is different from the filsystem's idmapping and the initial idmapping. + * If the initial mapping is used or the idmapping of the mount and the + * filesystem are identical no remapping is required. + * + * Return: true if remapping can be skipped, false if not. + */ +static inline bool no_idmapping(const struct user_namespace *mnt_userns, + const struct user_namespace *fs_userns) +{ + return initial_idmapping(mnt_userns) || mnt_userns == fs_userns; +} + +/** + * make_vfsuid - map a filesystem kuid according to an idmapping + * @idmap: the mount's idmapping + * @fs_userns: the filesystem's idmapping + * @kuid : kuid to be mapped + * + * Take a @kuid and remap it from @fs_userns into @idmap. Use this + * function when preparing a @kuid to be reported to userspace. + * + * If no_idmapping() determines that this is not an idmapped mount we can + * simply return @kuid unchanged. + * If initial_idmapping() tells us that the filesystem is not mounted with an + * idmapping we know the value of @kuid won't change when calling + * from_kuid() so we can simply retrieve the value via __kuid_val() + * directly. + * + * Return: @kuid mapped according to @idmap. + * If @kuid has no mapping in either @idmap or @fs_userns INVALID_UID is + * returned. + */ + +vfsuid_t make_vfsuid(struct mnt_idmap *idmap, + struct user_namespace *fs_userns, + kuid_t kuid) +{ + uid_t uid; + struct user_namespace *mnt_userns = idmap->owner; + + if (no_idmapping(mnt_userns, fs_userns)) + return VFSUIDT_INIT(kuid); + if (initial_idmapping(fs_userns)) + uid = __kuid_val(kuid); + else + uid = from_kuid(fs_userns, kuid); + if (uid == (uid_t)-1) + return INVALID_VFSUID; + return VFSUIDT_INIT(make_kuid(mnt_userns, uid)); +} +EXPORT_SYMBOL_GPL(make_vfsuid); + +/** + * make_vfsgid - map a filesystem kgid according to an idmapping + * @idmap: the mount's idmapping + * @fs_userns: the filesystem's idmapping + * @kgid : kgid to be mapped + * + * Take a @kgid and remap it from @fs_userns into @idmap. Use this + * function when preparing a @kgid to be reported to userspace. + * + * If no_idmapping() determines that this is not an idmapped mount we can + * simply return @kgid unchanged. + * If initial_idmapping() tells us that the filesystem is not mounted with an + * idmapping we know the value of @kgid won't change when calling + * from_kgid() so we can simply retrieve the value via __kgid_val() + * directly. + * + * Return: @kgid mapped according to @idmap. + * If @kgid has no mapping in either @idmap or @fs_userns INVALID_GID is + * returned. + */ +vfsgid_t make_vfsgid(struct mnt_idmap *idmap, + struct user_namespace *fs_userns, kgid_t kgid) +{ + gid_t gid; + struct user_namespace *mnt_userns = idmap->owner; + + if (no_idmapping(mnt_userns, fs_userns)) + return VFSGIDT_INIT(kgid); + if (initial_idmapping(fs_userns)) + gid = __kgid_val(kgid); + else + gid = from_kgid(fs_userns, kgid); + if (gid == (gid_t)-1) + return INVALID_VFSGID; + return VFSGIDT_INIT(make_kgid(mnt_userns, gid)); +} +EXPORT_SYMBOL_GPL(make_vfsgid); + +/** + * from_vfsuid - map a vfsuid into the filesystem idmapping + * @idmap: the mount's idmapping + * @fs_userns: the filesystem's idmapping + * @vfsuid : vfsuid to be mapped + * + * Map @vfsuid into the filesystem idmapping. This function has to be used in + * order to e.g. write @vfsuid to inode->i_uid. + * + * Return: @vfsuid mapped into the filesystem idmapping + */ +kuid_t from_vfsuid(struct mnt_idmap *idmap, + struct user_namespace *fs_userns, vfsuid_t vfsuid) +{ + uid_t uid; + struct user_namespace *mnt_userns = idmap->owner; + + if (no_idmapping(mnt_userns, fs_userns)) + return AS_KUIDT(vfsuid); + uid = from_kuid(mnt_userns, AS_KUIDT(vfsuid)); + if (uid == (uid_t)-1) + return INVALID_UID; + if (initial_idmapping(fs_userns)) + return KUIDT_INIT(uid); + return make_kuid(fs_userns, uid); +} +EXPORT_SYMBOL_GPL(from_vfsuid); + +/** + * from_vfsgid - map a vfsgid into the filesystem idmapping + * @idmap: the mount's idmapping + * @fs_userns: the filesystem's idmapping + * @vfsgid : vfsgid to be mapped + * + * Map @vfsgid into the filesystem idmapping. This function has to be used in + * order to e.g. write @vfsgid to inode->i_gid. + * + * Return: @vfsgid mapped into the filesystem idmapping + */ +kgid_t from_vfsgid(struct mnt_idmap *idmap, + struct user_namespace *fs_userns, vfsgid_t vfsgid) +{ + gid_t gid; + struct user_namespace *mnt_userns = idmap->owner; + + if (no_idmapping(mnt_userns, fs_userns)) + return AS_KGIDT(vfsgid); + gid = from_kgid(mnt_userns, AS_KGIDT(vfsgid)); + if (gid == (gid_t)-1) + return INVALID_GID; + if (initial_idmapping(fs_userns)) + return KGIDT_INIT(gid); + return make_kgid(fs_userns, gid); +} +EXPORT_SYMBOL_GPL(from_vfsgid); + +#ifdef CONFIG_MULTIUSER +/** + * vfsgid_in_group_p() - check whether a vfsuid matches the caller's groups + * @vfsgid: the mnt gid to match + * + * This function can be used to determine whether @vfsuid matches any of the + * caller's groups. + * + * Return: 1 if vfsuid matches caller's groups, 0 if not. + */ +int vfsgid_in_group_p(vfsgid_t vfsgid) +{ + return in_group_p(AS_KGIDT(vfsgid)); +} +#else +int vfsgid_in_group_p(vfsgid_t vfsgid) +{ + return 1; +} +#endif +EXPORT_SYMBOL_GPL(vfsgid_in_group_p); + +struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns) +{ + struct mnt_idmap *idmap; + + idmap = kzalloc(sizeof(struct mnt_idmap), GFP_KERNEL_ACCOUNT); + if (!idmap) + return ERR_PTR(-ENOMEM); + + idmap->owner = get_user_ns(mnt_userns); + refcount_set(&idmap->count, 1); + return idmap; +} + +/** + * mnt_idmap_get - get a reference to an idmapping + * @idmap: the idmap to bump the reference on + * + * If @idmap is not the @nop_mnt_idmap bump the reference count. + * + * Return: @idmap with reference count bumped if @not_mnt_idmap isn't passed. + */ +struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap) +{ + if (idmap != &nop_mnt_idmap) + refcount_inc(&idmap->count); + + return idmap; +} + +/** + * mnt_idmap_put - put a reference to an idmapping + * @idmap: the idmap to put the reference on + * + * If this is a non-initial idmapping, put the reference count when a mount is + * released and free it if we're the last user. + */ +void mnt_idmap_put(struct mnt_idmap *idmap) +{ + if (idmap != &nop_mnt_idmap && refcount_dec_and_test(&idmap->count)) { + put_user_ns(idmap->owner); + kfree(idmap); + } +} -- cgit v1.2.3