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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 /security/safesetid/lsm.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 'security/safesetid/lsm.c')
-rw-r--r-- | security/safesetid/lsm.c | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/security/safesetid/lsm.c b/security/safesetid/lsm.c new file mode 100644 index 000000000..e806739f7 --- /dev/null +++ b/security/safesetid/lsm.c @@ -0,0 +1,285 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * SafeSetID Linux Security Module + * + * Author: Micah Morton <mortonm@chromium.org> + * + * Copyright (C) 2018 The Chromium OS Authors. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2, as + * published by the Free Software Foundation. + * + */ + +#define pr_fmt(fmt) "SafeSetID: " fmt + +#include <linux/lsm_hooks.h> +#include <linux/module.h> +#include <linux/ptrace.h> +#include <linux/sched/task_stack.h> +#include <linux/security.h> +#include "lsm.h" + +/* Flag indicating whether initialization completed */ +int safesetid_initialized __initdata; + +struct setid_ruleset __rcu *safesetid_setuid_rules; +struct setid_ruleset __rcu *safesetid_setgid_rules; + + +/* Compute a decision for a transition from @src to @dst under @policy. */ +enum sid_policy_type _setid_policy_lookup(struct setid_ruleset *policy, + kid_t src, kid_t dst) +{ + struct setid_rule *rule; + enum sid_policy_type result = SIDPOL_DEFAULT; + + if (policy->type == UID) { + hash_for_each_possible(policy->rules, rule, next, __kuid_val(src.uid)) { + if (!uid_eq(rule->src_id.uid, src.uid)) + continue; + if (uid_eq(rule->dst_id.uid, dst.uid)) + return SIDPOL_ALLOWED; + result = SIDPOL_CONSTRAINED; + } + } else if (policy->type == GID) { + hash_for_each_possible(policy->rules, rule, next, __kgid_val(src.gid)) { + if (!gid_eq(rule->src_id.gid, src.gid)) + continue; + if (gid_eq(rule->dst_id.gid, dst.gid)){ + return SIDPOL_ALLOWED; + } + result = SIDPOL_CONSTRAINED; + } + } else { + /* Should not reach here, report the ID as contrainsted */ + result = SIDPOL_CONSTRAINED; + } + return result; +} + +/* + * Compute a decision for a transition from @src to @dst under the active + * policy. + */ +static enum sid_policy_type setid_policy_lookup(kid_t src, kid_t dst, enum setid_type new_type) +{ + enum sid_policy_type result = SIDPOL_DEFAULT; + struct setid_ruleset *pol; + + rcu_read_lock(); + if (new_type == UID) + pol = rcu_dereference(safesetid_setuid_rules); + else if (new_type == GID) + pol = rcu_dereference(safesetid_setgid_rules); + else { /* Should not reach here */ + result = SIDPOL_CONSTRAINED; + rcu_read_unlock(); + return result; + } + + if (pol) { + pol->type = new_type; + result = _setid_policy_lookup(pol, src, dst); + } + rcu_read_unlock(); + return result; +} + +static int safesetid_security_capable(const struct cred *cred, + struct user_namespace *ns, + int cap, + unsigned int opts) +{ + /* We're only interested in CAP_SETUID and CAP_SETGID. */ + if (cap != CAP_SETUID && cap != CAP_SETGID) + return 0; + + /* + * If CAP_SET{U/G}ID is currently used for a setid or setgroups syscall, we + * want to let it go through here; the real security check happens later, in + * the task_fix_set{u/g}id or task_fix_setgroups hooks. + */ + if ((opts & CAP_OPT_INSETID) != 0) + return 0; + + switch (cap) { + case CAP_SETUID: + /* + * If no policy applies to this task, allow the use of CAP_SETUID for + * other purposes. + */ + if (setid_policy_lookup((kid_t){.uid = cred->uid}, INVALID_ID, UID) == SIDPOL_DEFAULT) + return 0; + /* + * Reject use of CAP_SETUID for functionality other than calling + * set*uid() (e.g. setting up userns uid mappings). + */ + pr_warn("Operation requires CAP_SETUID, which is not available to UID %u for operations besides approved set*uid transitions\n", + __kuid_val(cred->uid)); + return -EPERM; + case CAP_SETGID: + /* + * If no policy applies to this task, allow the use of CAP_SETGID for + * other purposes. + */ + if (setid_policy_lookup((kid_t){.gid = cred->gid}, INVALID_ID, GID) == SIDPOL_DEFAULT) + return 0; + /* + * Reject use of CAP_SETUID for functionality other than calling + * set*gid() (e.g. setting up userns gid mappings). + */ + pr_warn("Operation requires CAP_SETGID, which is not available to GID %u for operations besides approved set*gid transitions\n", + __kuid_val(cred->uid)); + return -EPERM; + default: + /* Error, the only capabilities were checking for is CAP_SETUID/GID */ + return 0; + } + return 0; +} + +/* + * Check whether a caller with old credentials @old is allowed to switch to + * credentials that contain @new_id. + */ +static bool id_permitted_for_cred(const struct cred *old, kid_t new_id, enum setid_type new_type) +{ + bool permitted; + + /* If our old creds already had this ID in it, it's fine. */ + if (new_type == UID) { + if (uid_eq(new_id.uid, old->uid) || uid_eq(new_id.uid, old->euid) || + uid_eq(new_id.uid, old->suid)) + return true; + } else if (new_type == GID){ + if (gid_eq(new_id.gid, old->gid) || gid_eq(new_id.gid, old->egid) || + gid_eq(new_id.gid, old->sgid)) + return true; + } else /* Error, new_type is an invalid type */ + return false; + + /* + * Transitions to new UIDs require a check against the policy of the old + * RUID. + */ + permitted = + setid_policy_lookup((kid_t){.uid = old->uid}, new_id, new_type) != SIDPOL_CONSTRAINED; + + if (!permitted) { + if (new_type == UID) { + pr_warn("UID transition ((%d,%d,%d) -> %d) blocked\n", + __kuid_val(old->uid), __kuid_val(old->euid), + __kuid_val(old->suid), __kuid_val(new_id.uid)); + } else if (new_type == GID) { + pr_warn("GID transition ((%d,%d,%d) -> %d) blocked\n", + __kgid_val(old->gid), __kgid_val(old->egid), + __kgid_val(old->sgid), __kgid_val(new_id.gid)); + } else /* Error, new_type is an invalid type */ + return false; + } + return permitted; +} + +/* + * Check whether there is either an exception for user under old cred struct to + * set*uid to user under new cred struct, or the UID transition is allowed (by + * Linux set*uid rules) even without CAP_SETUID. + */ +static int safesetid_task_fix_setuid(struct cred *new, + const struct cred *old, + int flags) +{ + + /* Do nothing if there are no setuid restrictions for our old RUID. */ + if (setid_policy_lookup((kid_t){.uid = old->uid}, INVALID_ID, UID) == SIDPOL_DEFAULT) + return 0; + + if (id_permitted_for_cred(old, (kid_t){.uid = new->uid}, UID) && + id_permitted_for_cred(old, (kid_t){.uid = new->euid}, UID) && + id_permitted_for_cred(old, (kid_t){.uid = new->suid}, UID) && + id_permitted_for_cred(old, (kid_t){.uid = new->fsuid}, UID)) + return 0; + + /* + * Kill this process to avoid potential security vulnerabilities + * that could arise from a missing allowlist entry preventing a + * privileged process from dropping to a lesser-privileged one. + */ + force_sig(SIGKILL); + return -EACCES; +} + +static int safesetid_task_fix_setgid(struct cred *new, + const struct cred *old, + int flags) +{ + + /* Do nothing if there are no setgid restrictions for our old RGID. */ + if (setid_policy_lookup((kid_t){.gid = old->gid}, INVALID_ID, GID) == SIDPOL_DEFAULT) + return 0; + + if (id_permitted_for_cred(old, (kid_t){.gid = new->gid}, GID) && + id_permitted_for_cred(old, (kid_t){.gid = new->egid}, GID) && + id_permitted_for_cred(old, (kid_t){.gid = new->sgid}, GID) && + id_permitted_for_cred(old, (kid_t){.gid = new->fsgid}, GID)) + return 0; + + /* + * Kill this process to avoid potential security vulnerabilities + * that could arise from a missing allowlist entry preventing a + * privileged process from dropping to a lesser-privileged one. + */ + force_sig(SIGKILL); + return -EACCES; +} + +static int safesetid_task_fix_setgroups(struct cred *new, const struct cred *old) +{ + int i; + + /* Do nothing if there are no setgid restrictions for our old RGID. */ + if (setid_policy_lookup((kid_t){.gid = old->gid}, INVALID_ID, GID) == SIDPOL_DEFAULT) + return 0; + + get_group_info(new->group_info); + for (i = 0; i < new->group_info->ngroups; i++) { + if (!id_permitted_for_cred(old, (kid_t){.gid = new->group_info->gid[i]}, GID)) { + put_group_info(new->group_info); + /* + * Kill this process to avoid potential security vulnerabilities + * that could arise from a missing allowlist entry preventing a + * privileged process from dropping to a lesser-privileged one. + */ + force_sig(SIGKILL); + return -EACCES; + } + } + + put_group_info(new->group_info); + return 0; +} + +static struct security_hook_list safesetid_security_hooks[] = { + LSM_HOOK_INIT(task_fix_setuid, safesetid_task_fix_setuid), + LSM_HOOK_INIT(task_fix_setgid, safesetid_task_fix_setgid), + LSM_HOOK_INIT(task_fix_setgroups, safesetid_task_fix_setgroups), + LSM_HOOK_INIT(capable, safesetid_security_capable) +}; + +static int __init safesetid_security_init(void) +{ + security_add_hooks(safesetid_security_hooks, + ARRAY_SIZE(safesetid_security_hooks), "safesetid"); + + /* Report that SafeSetID successfully initialized */ + safesetid_initialized = 1; + + return 0; +} + +DEFINE_LSM(safesetid_security_init) = { + .init = safesetid_security_init, + .name = "safesetid", +}; |