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(). ... --- kernel/pid_namespace.c | 478 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 478 insertions(+) create mode 100644 kernel/pid_namespace.c (limited to 'kernel/pid_namespace.c') diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c new file mode 100644 index 000000000..fc21c5d5f --- /dev/null +++ b/kernel/pid_namespace.c @@ -0,0 +1,478 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Pid namespaces + * + * Authors: + * (C) 2007 Pavel Emelyanov , OpenVZ, SWsoft Inc. + * (C) 2007 Sukadev Bhattiprolu , IBM + * Many thanks to Oleg Nesterov for comments and help + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static DEFINE_MUTEX(pid_caches_mutex); +static struct kmem_cache *pid_ns_cachep; +/* Write once array, filled from the beginning. */ +static struct kmem_cache *pid_cache[MAX_PID_NS_LEVEL]; + +/* + * creates the kmem cache to allocate pids from. + * @level: pid namespace level + */ + +static struct kmem_cache *create_pid_cachep(unsigned int level) +{ + /* Level 0 is init_pid_ns.pid_cachep */ + struct kmem_cache **pkc = &pid_cache[level - 1]; + struct kmem_cache *kc; + char name[4 + 10 + 1]; + unsigned int len; + + kc = READ_ONCE(*pkc); + if (kc) + return kc; + + snprintf(name, sizeof(name), "pid_%u", level + 1); + len = sizeof(struct pid) + level * sizeof(struct upid); + mutex_lock(&pid_caches_mutex); + /* Name collision forces to do allocation under mutex. */ + if (!*pkc) + *pkc = kmem_cache_create(name, len, 0, + SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL); + mutex_unlock(&pid_caches_mutex); + /* current can fail, but someone else can succeed. */ + return READ_ONCE(*pkc); +} + +static struct ucounts *inc_pid_namespaces(struct user_namespace *ns) +{ + return inc_ucount(ns, current_euid(), UCOUNT_PID_NAMESPACES); +} + +static void dec_pid_namespaces(struct ucounts *ucounts) +{ + dec_ucount(ucounts, UCOUNT_PID_NAMESPACES); +} + +static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns, + struct pid_namespace *parent_pid_ns) +{ + struct pid_namespace *ns; + unsigned int level = parent_pid_ns->level + 1; + struct ucounts *ucounts; + int err; + + err = -EINVAL; + if (!in_userns(parent_pid_ns->user_ns, user_ns)) + goto out; + + err = -ENOSPC; + if (level > MAX_PID_NS_LEVEL) + goto out; + ucounts = inc_pid_namespaces(user_ns); + if (!ucounts) + goto out; + + err = -ENOMEM; + ns = kmem_cache_zalloc(pid_ns_cachep, GFP_KERNEL); + if (ns == NULL) + goto out_dec; + + idr_init(&ns->idr); + + ns->pid_cachep = create_pid_cachep(level); + if (ns->pid_cachep == NULL) + goto out_free_idr; + + err = ns_alloc_inum(&ns->ns); + if (err) + goto out_free_idr; + ns->ns.ops = &pidns_operations; + + refcount_set(&ns->ns.count, 1); + ns->level = level; + ns->parent = get_pid_ns(parent_pid_ns); + ns->user_ns = get_user_ns(user_ns); + ns->ucounts = ucounts; + ns->pid_allocated = PIDNS_ADDING; + + return ns; + +out_free_idr: + idr_destroy(&ns->idr); + kmem_cache_free(pid_ns_cachep, ns); +out_dec: + dec_pid_namespaces(ucounts); +out: + return ERR_PTR(err); +} + +static void delayed_free_pidns(struct rcu_head *p) +{ + struct pid_namespace *ns = container_of(p, struct pid_namespace, rcu); + + dec_pid_namespaces(ns->ucounts); + put_user_ns(ns->user_ns); + + kmem_cache_free(pid_ns_cachep, ns); +} + +static void destroy_pid_namespace(struct pid_namespace *ns) +{ + ns_free_inum(&ns->ns); + + idr_destroy(&ns->idr); + call_rcu(&ns->rcu, delayed_free_pidns); +} + +struct pid_namespace *copy_pid_ns(unsigned long flags, + struct user_namespace *user_ns, struct pid_namespace *old_ns) +{ + if (!(flags & CLONE_NEWPID)) + return get_pid_ns(old_ns); + if (task_active_pid_ns(current) != old_ns) + return ERR_PTR(-EINVAL); + return create_pid_namespace(user_ns, old_ns); +} + +void put_pid_ns(struct pid_namespace *ns) +{ + struct pid_namespace *parent; + + while (ns != &init_pid_ns) { + parent = ns->parent; + if (!refcount_dec_and_test(&ns->ns.count)) + break; + destroy_pid_namespace(ns); + ns = parent; + } +} +EXPORT_SYMBOL_GPL(put_pid_ns); + +void zap_pid_ns_processes(struct pid_namespace *pid_ns) +{ + int nr; + int rc; + struct task_struct *task, *me = current; + int init_pids = thread_group_leader(me) ? 1 : 2; + struct pid *pid; + + /* Don't allow any more processes into the pid namespace */ + disable_pid_allocation(pid_ns); + + /* + * Ignore SIGCHLD causing any terminated children to autoreap. + * This speeds up the namespace shutdown, plus see the comment + * below. + */ + spin_lock_irq(&me->sighand->siglock); + me->sighand->action[SIGCHLD - 1].sa.sa_handler = SIG_IGN; + spin_unlock_irq(&me->sighand->siglock); + + /* + * The last thread in the cgroup-init thread group is terminating. + * Find remaining pid_ts in the namespace, signal and wait for them + * to exit. + * + * Note: This signals each threads in the namespace - even those that + * belong to the same thread group, To avoid this, we would have + * to walk the entire tasklist looking a processes in this + * namespace, but that could be unnecessarily expensive if the + * pid namespace has just a few processes. Or we need to + * maintain a tasklist for each pid namespace. + * + */ + rcu_read_lock(); + read_lock(&tasklist_lock); + nr = 2; + idr_for_each_entry_continue(&pid_ns->idr, pid, nr) { + task = pid_task(pid, PIDTYPE_PID); + if (task && !__fatal_signal_pending(task)) + group_send_sig_info(SIGKILL, SEND_SIG_PRIV, task, PIDTYPE_MAX); + } + read_unlock(&tasklist_lock); + rcu_read_unlock(); + + /* + * Reap the EXIT_ZOMBIE children we had before we ignored SIGCHLD. + * kernel_wait4() will also block until our children traced from the + * parent namespace are detached and become EXIT_DEAD. + */ + do { + clear_thread_flag(TIF_SIGPENDING); + rc = kernel_wait4(-1, NULL, __WALL, NULL); + } while (rc != -ECHILD); + + /* + * kernel_wait4() misses EXIT_DEAD children, and EXIT_ZOMBIE + * process whose parents processes are outside of the pid + * namespace. Such processes are created with setns()+fork(). + * + * If those EXIT_ZOMBIE processes are not reaped by their + * parents before their parents exit, they will be reparented + * to pid_ns->child_reaper. Thus pidns->child_reaper needs to + * stay valid until they all go away. + * + * The code relies on the pid_ns->child_reaper ignoring + * SIGCHILD to cause those EXIT_ZOMBIE processes to be + * autoreaped if reparented. + * + * Semantically it is also desirable to wait for EXIT_ZOMBIE + * processes before allowing the child_reaper to be reaped, as + * that gives the invariant that when the init process of a + * pid namespace is reaped all of the processes in the pid + * namespace are gone. + * + * Once all of the other tasks are gone from the pid_namespace + * free_pid() will awaken this task. + */ + for (;;) { + set_current_state(TASK_INTERRUPTIBLE); + if (pid_ns->pid_allocated == init_pids) + break; + /* + * Release tasks_rcu_exit_srcu to avoid following deadlock: + * + * 1) TASK A unshare(CLONE_NEWPID) + * 2) TASK A fork() twice -> TASK B (child reaper for new ns) + * and TASK C + * 3) TASK B exits, kills TASK C, waits for TASK A to reap it + * 4) TASK A calls synchronize_rcu_tasks() + * -> synchronize_srcu(tasks_rcu_exit_srcu) + * 5) *DEADLOCK* + * + * It is considered safe to release tasks_rcu_exit_srcu here + * because we assume the current task can not be concurrently + * reaped at this point. + */ + exit_tasks_rcu_stop(); + schedule(); + exit_tasks_rcu_start(); + } + __set_current_state(TASK_RUNNING); + + if (pid_ns->reboot) + current->signal->group_exit_code = pid_ns->reboot; + + acct_exit_ns(pid_ns); + return; +} + +#ifdef CONFIG_CHECKPOINT_RESTORE +static int pid_ns_ctl_handler(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct pid_namespace *pid_ns = task_active_pid_ns(current); + struct ctl_table tmp = *table; + int ret, next; + + if (write && !checkpoint_restore_ns_capable(pid_ns->user_ns)) + return -EPERM; + + /* + * Writing directly to ns' last_pid field is OK, since this field + * is volatile in a living namespace anyway and a code writing to + * it should synchronize its usage with external means. + */ + + next = idr_get_cursor(&pid_ns->idr) - 1; + + tmp.data = &next; + ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); + if (!ret && write) + idr_set_cursor(&pid_ns->idr, next + 1); + + return ret; +} + +extern int pid_max; +static struct ctl_table pid_ns_ctl_table[] = { + { + .procname = "ns_last_pid", + .maxlen = sizeof(int), + .mode = 0666, /* permissions are checked in the handler */ + .proc_handler = pid_ns_ctl_handler, + .extra1 = SYSCTL_ZERO, + .extra2 = &pid_max, + }, + { } +}; +static struct ctl_path kern_path[] = { { .procname = "kernel", }, { } }; +#endif /* CONFIG_CHECKPOINT_RESTORE */ + +int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd) +{ + if (pid_ns == &init_pid_ns) + return 0; + + switch (cmd) { + case LINUX_REBOOT_CMD_RESTART2: + case LINUX_REBOOT_CMD_RESTART: + pid_ns->reboot = SIGHUP; + break; + + case LINUX_REBOOT_CMD_POWER_OFF: + case LINUX_REBOOT_CMD_HALT: + pid_ns->reboot = SIGINT; + break; + default: + return -EINVAL; + } + + read_lock(&tasklist_lock); + send_sig(SIGKILL, pid_ns->child_reaper, 1); + read_unlock(&tasklist_lock); + + do_exit(0); + + /* Not reached */ + return 0; +} + +static inline struct pid_namespace *to_pid_ns(struct ns_common *ns) +{ + return container_of(ns, struct pid_namespace, ns); +} + +static struct ns_common *pidns_get(struct task_struct *task) +{ + struct pid_namespace *ns; + + rcu_read_lock(); + ns = task_active_pid_ns(task); + if (ns) + get_pid_ns(ns); + rcu_read_unlock(); + + return ns ? &ns->ns : NULL; +} + +static struct ns_common *pidns_for_children_get(struct task_struct *task) +{ + struct pid_namespace *ns = NULL; + + task_lock(task); + if (task->nsproxy) { + ns = task->nsproxy->pid_ns_for_children; + get_pid_ns(ns); + } + task_unlock(task); + + if (ns) { + read_lock(&tasklist_lock); + if (!ns->child_reaper) { + put_pid_ns(ns); + ns = NULL; + } + read_unlock(&tasklist_lock); + } + + return ns ? &ns->ns : NULL; +} + +static void pidns_put(struct ns_common *ns) +{ + put_pid_ns(to_pid_ns(ns)); +} + +static int pidns_install(struct nsset *nsset, struct ns_common *ns) +{ + struct nsproxy *nsproxy = nsset->nsproxy; + struct pid_namespace *active = task_active_pid_ns(current); + struct pid_namespace *ancestor, *new = to_pid_ns(ns); + + if (!ns_capable(new->user_ns, CAP_SYS_ADMIN) || + !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN)) + return -EPERM; + + /* + * Only allow entering the current active pid namespace + * or a child of the current active pid namespace. + * + * This is required for fork to return a usable pid value and + * this maintains the property that processes and their + * children can not escape their current pid namespace. + */ + if (new->level < active->level) + return -EINVAL; + + ancestor = new; + while (ancestor->level > active->level) + ancestor = ancestor->parent; + if (ancestor != active) + return -EINVAL; + + put_pid_ns(nsproxy->pid_ns_for_children); + nsproxy->pid_ns_for_children = get_pid_ns(new); + return 0; +} + +static struct ns_common *pidns_get_parent(struct ns_common *ns) +{ + struct pid_namespace *active = task_active_pid_ns(current); + struct pid_namespace *pid_ns, *p; + + /* See if the parent is in the current namespace */ + pid_ns = p = to_pid_ns(ns)->parent; + for (;;) { + if (!p) + return ERR_PTR(-EPERM); + if (p == active) + break; + p = p->parent; + } + + return &get_pid_ns(pid_ns)->ns; +} + +static struct user_namespace *pidns_owner(struct ns_common *ns) +{ + return to_pid_ns(ns)->user_ns; +} + +const struct proc_ns_operations pidns_operations = { + .name = "pid", + .type = CLONE_NEWPID, + .get = pidns_get, + .put = pidns_put, + .install = pidns_install, + .owner = pidns_owner, + .get_parent = pidns_get_parent, +}; + +const struct proc_ns_operations pidns_for_children_operations = { + .name = "pid_for_children", + .real_ns_name = "pid", + .type = CLONE_NEWPID, + .get = pidns_for_children_get, + .put = pidns_put, + .install = pidns_install, + .owner = pidns_owner, + .get_parent = pidns_get_parent, +}; + +static __init int pid_namespaces_init(void) +{ + pid_ns_cachep = KMEM_CACHE(pid_namespace, SLAB_PANIC | SLAB_ACCOUNT); + +#ifdef CONFIG_CHECKPOINT_RESTORE + register_sysctl_paths(kern_path, pid_ns_ctl_table); +#endif + return 0; +} + +__initcall(pid_namespaces_init); -- cgit v1.2.3