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2019-10-25netns: fix GFP flags in rtnl_net_notifyid()Guillaume Nault1-8/+9
In rtnl_net_notifyid(), we certainly can't pass a null GFP flag to rtnl_notify(). A GFP_KERNEL flag would be fine in most circumstances, but there are a few paths calling rtnl_net_notifyid() from atomic context or from RCU critical sections. The later also precludes the use of gfp_any() as it wouldn't detect the RCU case. Also, the nlmsg_new() call is wrong too, as it uses GFP_KERNEL unconditionally. Therefore, we need to pass the GFP flags as parameter and propagate it through function calls until the proper flags can be determined. In most cases, GFP_KERNEL is fine. The exceptions are: * openvswitch: ovs_vport_cmd_get() and ovs_vport_cmd_dump() indirectly call rtnl_net_notifyid() from RCU critical section, * rtnetlink: rtmsg_ifinfo_build_skb() already receives GFP flags as parameter. Also, in ovs_vport_cmd_build_info(), let's change the GFP flags used by nlmsg_new(). The function is allowed to sleep, so better make the flags consistent with the ones used in the following ovs_vport_cmd_fill_info() call. Found by code inspection. Fixes: 9a9634545c70 ("netns: notify netns id events") Signed-off-by: Guillaume Nault <gnault@redhat.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Pravin B Shelar <pshelar@ovn.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-24keys: Fix memory leak in copy_net_nsTakeshi Misawa1-0/+1
If copy_net_ns() failed after net_alloc(), net->key_domain is leaked. Fix this, by freeing key_domain in error path. syzbot report: BUG: memory leak unreferenced object 0xffff8881175007e0 (size 32): comm "syz-executor902", pid 7069, jiffies 4294944350 (age 28.400s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000a83ed741>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] [<00000000a83ed741>] slab_post_alloc_hook mm/slab.h:439 [inline] [<00000000a83ed741>] slab_alloc mm/slab.c:3326 [inline] [<00000000a83ed741>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 [<0000000059fc92b9>] kmalloc include/linux/slab.h:547 [inline] [<0000000059fc92b9>] kzalloc include/linux/slab.h:742 [inline] [<0000000059fc92b9>] net_alloc net/core/net_namespace.c:398 [inline] [<0000000059fc92b9>] copy_net_ns+0xb2/0x220 net/core/net_namespace.c:445 [<00000000a9d74bbc>] create_new_namespaces+0x141/0x2a0 kernel/nsproxy.c:103 [<000000008047d645>] unshare_nsproxy_namespaces+0x7f/0x100 kernel/nsproxy.c:202 [<000000005993ea6e>] ksys_unshare+0x236/0x490 kernel/fork.c:2674 [<0000000019417e75>] __do_sys_unshare kernel/fork.c:2742 [inline] [<0000000019417e75>] __se_sys_unshare kernel/fork.c:2740 [inline] [<0000000019417e75>] __x64_sys_unshare+0x16/0x20 kernel/fork.c:2740 [<00000000f4c5f2c8>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:296 [<0000000038550184>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 syzbot also reported other leak in copy_net_ns -> setup_net. This problem is already fixed by cf47a0b882a4e5f6b34c7949d7b293e9287f1972. Fixes: 9b242610514f ("keys: Network namespace domain tag") Reported-and-tested-by: syzbot+3b3296d032353c33184b@syzkaller.appspotmail.com Signed-off-by: Takeshi Misawa <jeliantsurux@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-09netns: fix NLM_F_ECHO mechanism for RTM_NEWNSIDNicolas Dichtel1-6/+11
The flag NLM_F_ECHO aims to reply to the user the message notified to all listeners. It was not the case with the command RTM_NEWNSID, let's fix this. Fixes: 0c7aecd4bde4 ("netns: add rtnl cmd to add and get peer netns ids") Reported-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Guillaume Nault <gnault@redhat.com> Tested-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-07-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds1-0/+28
Pull networking updates from David Miller: "Some highlights from this development cycle: 1) Big refactoring of ipv6 route and neigh handling to support nexthop objects configurable as units from userspace. From David Ahern. 2) Convert explored_states in BPF verifier into a hash table, significantly decreased state held for programs with bpf2bpf calls, from Alexei Starovoitov. 3) Implement bpf_send_signal() helper, from Yonghong Song. 4) Various classifier enhancements to mvpp2 driver, from Maxime Chevallier. 5) Add aRFS support to hns3 driver, from Jian Shen. 6) Fix use after free in inet frags by allocating fqdirs dynamically and reworking how rhashtable dismantle occurs, from Eric Dumazet. 7) Add act_ctinfo packet classifier action, from Kevin Darbyshire-Bryant. 8) Add TFO key backup infrastructure, from Jason Baron. 9) Remove several old and unused ISDN drivers, from Arnd Bergmann. 10) Add devlink notifications for flash update status to mlxsw driver, from Jiri Pirko. 11) Lots of kTLS offload infrastructure fixes, from Jakub Kicinski. 12) Add support for mv88e6250 DSA chips, from Rasmus Villemoes. 13) Various enhancements to ipv6 flow label handling, from Eric Dumazet and Willem de Bruijn. 14) Support TLS offload in nfp driver, from Jakub Kicinski, Dirk van der Merwe, and others. 15) Various improvements to axienet driver including converting it to phylink, from Robert Hancock. 16) Add PTP support to sja1105 DSA driver, from Vladimir Oltean. 17) Add mqprio qdisc offload support to dpaa2-eth, from Ioana Radulescu. 18) Add devlink health reporting to mlx5, from Moshe Shemesh. 19) Convert stmmac over to phylink, from Jose Abreu. 20) Add PTP PHC (Physical Hardware Clock) support to mlxsw, from Shalom Toledo. 21) Add nftables SYNPROXY support, from Fernando Fernandez Mancera. 22) Convert tcp_fastopen over to use SipHash, from Ard Biesheuvel. 23) Track spill/fill of constants in BPF verifier, from Alexei Starovoitov. 24) Support bounded loops in BPF, from Alexei Starovoitov. 25) Various page_pool API fixes and improvements, from Jesper Dangaard Brouer. 26) Just like ipv4, support ref-countless ipv6 route handling. From Wei Wang. 27) Support VLAN offloading in aquantia driver, from Igor Russkikh. 28) Add AF_XDP zero-copy support to mlx5, from Maxim Mikityanskiy. 29) Add flower GRE encap/decap support to nfp driver, from Pieter Jansen van Vuuren. 30) Protect against stack overflow when using act_mirred, from John Hurley. 31) Allow devmap map lookups from eBPF, from Toke Høiland-Jørgensen. 32) Use page_pool API in netsec driver, Ilias Apalodimas. 33) Add Google gve network driver, from Catherine Sullivan. 34) More indirect call avoidance, from Paolo Abeni. 35) Add kTLS TX HW offload support to mlx5, from Tariq Toukan. 36) Add XDP_REDIRECT support to bnxt_en, from Andy Gospodarek. 37) Add MPLS manipulation actions to TC, from John Hurley. 38) Add sending a packet to connection tracking from TC actions, and then allow flower classifier matching on conntrack state. From Paul Blakey. 39) Netfilter hw offload support, from Pablo Neira Ayuso" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2080 commits) net/mlx5e: Return in default case statement in tx_post_resync_params mlx5: Return -EINVAL when WARN_ON_ONCE triggers in mlx5e_tls_resync(). net: dsa: add support for BRIDGE_MROUTER attribute pkt_sched: Include const.h net: netsec: remove static declaration for netsec_set_tx_de() net: netsec: remove superfluous if statement netfilter: nf_tables: add hardware offload support net: flow_offload: rename tc_cls_flower_offload to flow_cls_offload net: flow_offload: add flow_block_cb_is_busy() and use it net: sched: remove tcf block API drivers: net: use flow block API net: sched: use flow block API net: flow_offload: add flow_block_cb_{priv, incref, decref}() net: flow_offload: add list handling functions net: flow_offload: add flow_block_cb_alloc() and flow_block_cb_free() net: flow_offload: rename TCF_BLOCK_BINDER_TYPE_* to FLOW_BLOCK_BINDER_TYPE_* net: flow_offload: rename TC_BLOCK_{UN}BIND to FLOW_BLOCK_{UN}BIND net: flow_offload: add flow_block_cb_setup_simple() net: hisilicon: Add an tx_desc to adapt HI13X1_GMAC net: hisilicon: Add an rx_desc to adapt HI13X1_GMAC ...
2019-07-08Merge tag 'keys-namespace-20190627' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fsLinus Torvalds1-0/+20
Pull keyring namespacing from David Howells: "These patches help make keys and keyrings more namespace aware. Firstly some miscellaneous patches to make the process easier: - Simplify key index_key handling so that the word-sized chunks assoc_array requires don't have to be shifted about, making it easier to add more bits into the key. - Cache the hash value in the key so that we don't have to calculate on every key we examine during a search (it involves a bunch of multiplications). - Allow keying_search() to search non-recursively. Then the main patches: - Make it so that keyring names are per-user_namespace from the point of view of KEYCTL_JOIN_SESSION_KEYRING so that they're not accessible cross-user_namespace. keyctl_capabilities() shows KEYCTL_CAPS1_NS_KEYRING_NAME for this. - Move the user and user-session keyrings to the user_namespace rather than the user_struct. This prevents them propagating directly across user_namespaces boundaries (ie. the KEY_SPEC_* flags will only pick from the current user_namespace). - Make it possible to include the target namespace in which the key shall operate in the index_key. This will allow the possibility of multiple keys with the same description, but different target domains to be held in the same keyring. keyctl_capabilities() shows KEYCTL_CAPS1_NS_KEY_TAG for this. - Make it so that keys are implicitly invalidated by removal of a domain tag, causing them to be garbage collected. - Institute a network namespace domain tag that allows keys to be differentiated by the network namespace in which they operate. New keys that are of a type marked 'KEY_TYPE_NET_DOMAIN' are assigned the network domain in force when they are created. - Make it so that the desired network namespace can be handed down into the request_key() mechanism. This allows AFS, NFS, etc. to request keys specific to the network namespace of the superblock. This also means that the keys in the DNS record cache are thenceforth namespaced, provided network filesystems pass the appropriate network namespace down into dns_query(). For DNS, AFS and NFS are good, whilst CIFS and Ceph are not. Other cache keyrings, such as idmapper keyrings, also need to set the domain tag - for which they need access to the network namespace of the superblock" * tag 'keys-namespace-20190627' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: keys: Pass the network namespace into request_key mechanism keys: Network namespace domain tag keys: Garbage collect keys for which the domain has been removed keys: Include target namespace in match criteria keys: Move the user and user-session keyrings to the user_namespace keys: Namespace keyring names keys: Add a 'recurse' flag for keyring searches keys: Cache the hash value to avoid lots of recalculation keys: Simplify key description management
2019-06-26keys: Network namespace domain tagDavid Howells1-0/+20
Create key domain tags for network namespaces and make it possible to automatically tag keys that are used by networked services (e.g. AF_RXRPC, AFS, DNS) with the default network namespace if not set by the caller. This allows keys with the same description but in different namespaces to coexist within a keyring. Signed-off-by: David Howells <dhowells@redhat.com> cc: netdev@vger.kernel.org cc: linux-nfs@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: linux-afs@lists.infradead.org
2019-06-22netns: restore ops before calling ops_exit_listLi RongQing1-1/+1
ops has been iterated to first element when call pre_exit, and it needs to restore from save_ops, not save ops to save_ops Fixes: d7d99872c144 ("netns: add pre_exit method to struct pernet_operations") Signed-off-by: Li RongQing <lirongqing@baidu.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-19netns: add pre_exit method to struct pernet_operationsEric Dumazet1-0/+28
Current struct pernet_operations exit() handlers are highly discouraged to call synchronize_rcu(). There are cases where we need them, and exit_batch() does not help the common case where a single netns is dismantled. This patch leverages the existing synchronize_rcu() call in cleanup_net() Calling optional ->pre_exit() method before ->exit() or ->exit_batch() allows to benefit from a single synchronize_rcu() call. Note that the synchronize_rcu() calls added in this patch are only in error paths or slow paths. Tested: $ time for i in {1..1000}; do unshare -n /bin/false;done real 0m2.612s user 0m0.171s sys 0m2.216s Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-21treewide: Add SPDX license identifier for missed filesThomas Gleixner1-0/+1
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-27netlink: make validation more configurable for future strictnessJohannes Berg1-8/+11
We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-11netns: read NETNSA_NSID as s32 attribute in rtnl_net_getid()Guillaume Nault1-1/+1
NETNSA_NSID is signed. Use nla_get_s32() to avoid confusion. Signed-off-by: Guillaume Nault <gnault@redhat.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-28netns: provide pure entropy for net_hash_mix()Eric Dumazet1-0/+1
net_hash_mix() currently uses kernel address of a struct net, and is used in many places that could be used to reveal this address to a patient attacker, thus defeating KASLR, for the typical case (initial net namespace, &init_net is not dynamically allocated) I believe the original implementation tried to avoid spending too many cycles in this function, but security comes first. Also provide entropy regardless of CONFIG_NET_NS. Fixes: 0b4419162aa6 ("netns: introduce the net_hash_mix "salt" for hashes") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Amit Klein <aksecurity@gmail.com> Reported-by: Benny Pinkas <benny@pinkas.net> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-19net: namespace: perform strict checks also for doit handlersJakub Kicinski1-2/+36
Make RTM_GETNSID's doit handler use strict checks when NETLINK_F_STRICT_CHK is set. v2: - don't check size >= sizeof(struct rtgenmsg) (Nicolas). Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-1/+2
Pull in bug fixes before respinning my net-next pull request. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-24net/net_namespace: Check the return value of register_pernet_subsys()Aditya Pakki1-1/+2
In net_ns_init(), register_pernet_subsys() could fail while registering network namespace subsystems. The fix checks the return value and sends a panic() on failure. Signed-off-by: Aditya Pakki <pakki001@umn.edu> Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-27netns: enable to dump full nsid translation tableNicolas Dichtel1-6/+26
Like the previous patch, the goal is to ease to convert nsids from one netns to another netns. A new attribute (NETNSA_CURRENT_NSID) is added to the kernel answer when NETNSA_TARGET_NSID is provided, thus the user can easily convert nsids. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-27netns: enable to specify a nsid for a get requestNicolas Dichtel1-0/+5
Combined with NETNSA_TARGET_NSID, it enables to "translate" a nsid from one netns to a nsid of another netns. This is useful when using NETLINK_F_LISTEN_ALL_NSID because it helps the user to interpret a nsid received from an other netns. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-27netns: add support of NETNSA_TARGET_NSIDNicolas Dichtel1-11/+75
Like it was done for link and address, add the ability to perform get/dump in another netns by specifying a target nsid attribute. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-27netns: introduce 'struct net_fill_args'Nicolas Dichtel1-14/+34
This is a preparatory work. To avoid having to much arguments for the function rtnl_net_fill(), a new structure is defined. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-27netns: remove net arg from rtnl_net_fill()Nicolas Dichtel1-6/+4
This argument is not used anymore. Fixes: cab3c8ec8d57 ("netns: always provide the id to rtnl_net_fill()") Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-08net/namespace: Update rtnl_net_dumpid for strict data checkingDavid Ahern1-0/+6
Update rtnl_net_dumpid for strict data checking. If the flag is set, the dump request is expected to have an rtgenmsg struct as the header which has the family as the only element. No data may be appended. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-26Merge branch 'ida-4.19' of git://git.infradead.org/users/willy/linux-daxLinus Torvalds1-10/+6
Pull IDA updates from Matthew Wilcox: "A better IDA API: id = ida_alloc(ida, GFP_xxx); ida_free(ida, id); rather than the cumbersome ida_simple_get(), ida_simple_remove(). The new IDA API is similar to ida_simple_get() but better named. The internal restructuring of the IDA code removes the bitmap preallocation nonsense. I hope the net -200 lines of code is convincing" * 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax: (29 commits) ida: Change ida_get_new_above to return the id ida: Remove old API test_ida: check_ida_destroy and check_ida_alloc test_ida: Convert check_ida_conv to new API test_ida: Move ida_check_max test_ida: Move ida_check_leaf idr-test: Convert ida_check_nomem to new API ida: Start new test_ida module target/iscsi: Allocate session IDs from an IDA iscsi target: fix session creation failure handling drm/vmwgfx: Convert to new IDA API dmaengine: Convert to new IDA API ppc: Convert vas ID allocation to new IDA API media: Convert entity ID allocation to new IDA API ppc: Convert mmu context allocation to new IDA API Convert net_namespace to new IDA API cb710: Convert to new IDA API rsxx: Convert to new IDA API osd: Convert to new IDA API sd: Convert to new IDA API ...
2018-08-21Convert net_namespace to new IDA APIMatthew Wilcox1-10/+6
Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-07-20net: create reusable function for getting ownership info of sysfs inodesTyler Hicks1-0/+28
Make net_ns_get_ownership() reusable by networking code outside of core. This is useful, for example, to allow bridge related sysfs files to be owned by container root. Add a function comment since this is a potentially dangerous function to use given the way that kobject_get_ownership() works by initializing uid and gid before calling .get_ownership(). Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31net: Do not take net_rwsem in __rtnl_link_unregister()Kirill Tkhai1-0/+1
This function calls call_netdevice_notifier(), which also may take net_rwsem. So, we can't use net_rwsem here. This patch makes callers of this functions take pernet_ops_rwsem, like register_netdevice_notifier() does. This will protect the modifications of net_namespace_list, and allows notifiers to take it (they won't have to care about context). Since __rtnl_link_unregister() is used on module load and unload (which are not frequent operations), this looks for me better, than make all call_netdevice_notifier() always executing in "protected net_namespace_list" context. Also, this fixes the problem we had a deal in 328fbe747ad4 "Close race between {un, }register_netdevice_notifier and ...", and guarantees __rtnl_link_unregister() does not skip exitting net. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-29net: Introduce net_rwsem to protect net_namespace_listKirill Tkhai1-5/+13
rtnl_lock() is used everywhere, and contention is very high. When someone wants to iterate over alive net namespaces, he/she has no a possibility to do that without exclusive lock. But the exclusive rtnl_lock() in such places is overkill, and it just increases the contention. Yes, there is already for_each_net_rcu() in kernel, but it requires rcu_read_lock(), and this can't be sleepable. Also, sometimes it may be need really prevent net_namespace_list growth, so for_each_net_rcu() is not fit there. This patch introduces new rw_semaphore, which will be used instead of rtnl_mutex to protect net_namespace_list. It is sleepable and allows not-exclusive iterations over net namespaces list. It allows to stop using rtnl_lock() in several places (what is made in next patches) and makes less the time, we keep rtnl_mutex. Here we just add new lock, while the explanation of we can remove rtnl_lock() there are in next patches. Fine grained locks generally are better, then one big lock, so let's do that with net_namespace_list, while the situation allows that. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27net: Add more commentsKirill Tkhai1-0/+2
This adds comments to different places to improve readability. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27net: Rename net_sem to pernet_ops_rwsemKirill Tkhai1-20/+20
net_sem is some undefined area name, so it will be better to make the area more defined. Rename it to pernet_ops_rwsem for better readability and better intelligibility. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27net: Drop pernet_operations::asyncKirill Tkhai1-2/+0
Synchronous pernet_operations are not allowed anymore. All are asynchronous. So, drop the structure member. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27net: Reflect all pernet_operations are convertedKirill Tkhai1-37/+6
All pernet_operations are reviewed and converted, hooray! Reflect this in core code: setup_net() and cleanup_net() will take down_read() always. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-22net: Replace ip_ra_lock with per-net mutexKirill Tkhai1-0/+1
Since ra_chain is per-net, we may use per-net mutexes to protect them in ip_ra_control(). This improves scalability. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-07net: Make account struct net to memcgKirill Tkhai1-1/+1
The patch adds SLAB_ACCOUNT to flags of net_cachep cache, which enables accounting of struct net memory to memcg kmem. Since number of net_namespaces may be significant, user want to know, how much there were consumed, and control. Note, that we do not account net_generic to the same memcg, where net was accounted, moreover, we don't do this at all (*). We do not want the situation, when single memcg memory deficit prevents us to register new pernet_operations. (*)Even despite there is !current process accounting already available in linux-next. See kmalloc_memcg() there for the details. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-26net: make kmem caches as __ro_after_initAlexey Dobriyan1-1/+1
All kmem caches aren't reallocated once set up. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-20net: Queue net_cleanup_work only if there is first net addedKirill Tkhai1-2/+2
When llist_add() returns false, cleanup_net() hasn't made its llist_del_all(), while the work has already been scheduled by the first queuer. So, we may skip queue_work() in this case. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-20net: Make cleanup_list and net::cleanup_list of llist typeKirill Tkhai1-14/+6
This simplifies cleanup queueing and makes cleanup lists to use llist primitives. Since llist has its own cmpxchg() ordering, cleanup_list_lock is not more need. Also, struct llist_node is smaller, than struct list_head, so we save some bytes in struct net with this patch. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-20net: Kill net_mutexKirill Tkhai1-21/+32
We take net_mutex, when there are !async pernet_operations registered, and read locking of net_sem is not enough. But we may get rid of taking the mutex, and just change the logic to write lock net_sem in such cases. This obviously reduces the number of lock operations, we do. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-13net: Convert net_defaults_opsKirill Tkhai1-0/+1
net_defaults_ops introduce only net_defaults_init_net method, and it acts on net::core::sysctl_somaxconn, which is not interesting for the rest of pernet_subsys and pernet_device lists. Then, make them async. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-13net: Convert net_ns_ops methodsKirill Tkhai1-0/+1
This patch starts to convert pernet_subsys, registered from pure initcalls. net_ns_ops::net_ns_net_init/net_ns_net_init, methods use only ida_simple_* functions, which are not need a synchronization. They are synchronized by idr subsystem. So, net_ns_ops methods are able to be executed in parallel with methods of other pernet operations. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-13net: Allow pernet_operations to be executed in parallelKirill Tkhai1-10/+20
This adds new pernet_operations::async flag to indicate operations, which ->init(), ->exit() and ->exit_batch() methods are allowed to be executed in parallel with the methods of any other pernet_operations. When there are only asynchronous pernet_operations in the system, net_mutex won't be taken for a net construction and destruction. Also, remove BUG_ON(mutex_is_locked()) from net_assign_generic() without replacing with the equivalent net_sem check, as there is one more lockdep assert below. v3: Add comment near net_mutex. Suggested-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-13net: Move mutex_unlock() in cleanup_net() upKirill Tkhai1-1/+2
net_sem protects from pernet_list changing, while ops_free_list() makes simple kfree(), and it can't race with other pernet_operations callbacks. So we may release net_mutex earlier then it was. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-13net: Introduce net_sem for protection of pernet_listKirill Tkhai1-13/+26
Currently, the mutex is mostly used to protect pernet operations list. It orders setup_net() and cleanup_net() with parallel {un,}register_pernet_operations() calls, so ->exit{,batch} methods of the same pernet operations are executed for a dying net, as were used to call ->init methods, even after the net namespace is unlinked from net_namespace_list in cleanup_net(). But there are several problems with scalability. The first one is that more than one net can't be created or destroyed at the same moment on the node. For big machines with many cpus running many containers it's very sensitive. The second one is that it's need to synchronize_rcu() after net is removed from net_namespace_list(): Destroy net_ns: cleanup_net() mutex_lock(&net_mutex) list_del_rcu(&net->list) synchronize_rcu() <--- Sleep there for ages list_for_each_entry_reverse(ops, &pernet_list, list) ops_exit_list(ops, &net_exit_list) list_for_each_entry_reverse(ops, &pernet_list, list) ops_free_list(ops, &net_exit_list) mutex_unlock(&net_mutex) This primitive is not fast, especially on the systems with many processors and/or when preemptible RCU is enabled in config. So, all the time, while cleanup_net() is waiting for RCU grace period, creation of new net namespaces is not possible, the tasks, who makes it, are sleeping on the same mutex: Create net_ns: copy_net_ns() mutex_lock_killable(&net_mutex) <--- Sleep there for ages I observed 20-30 seconds hangs of "unshare -n" on ordinary 8-cpu laptop with preemptible RCU enabled after CRIU tests round is finished. The solution is to convert net_mutex to the rw_semaphore and add fine grain locks to really small number of pernet_operations, what really need them. Then, pernet_operations::init/::exit methods, modifying the net-related data, will require down_read() locking only, while down_write() will be used for changing pernet_list (i.e., when modules are being loaded and unloaded). This gives signify performance increase, after all patch set is applied, like you may see here: %for i in {1..10000}; do unshare -n bash -c exit; done *before* real 1m40,377s user 0m9,672s sys 0m19,928s *after* real 0m17,007s user 0m5,311s sys 0m11,779 (5.8 times faster) This patch starts replacing net_mutex to net_sem. It adds rw_semaphore, describes the variables it protects, and makes to use, where appropriate. net_mutex is still present, and next patches will kick it out step-by-step. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-13net: Cleanup in copy_net_ns()Kirill Tkhai1-11/+9
Line up destructors actions in the revers order to constructors. Next patches will add more actions, and this will be comfortable, if there is the such order. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-13net: Assign net to net_namespace_list in setup_net()Kirill Tkhai1-10/+3
This patch merges two repeating pieces of code in one, and they will live in setup_net() now. The only change is that assignment: init_net_initialized = true; becomes reordered with: list_add_tail_rcu(&net->list, &net_namespace_list); The order does not have visible effect, and it is a simple cleanup because of: init_net_initialized is used in !CONFIG_NET_NS case to order proc_net_ns_ops registration occuring at boot time: start_kernel()->proc_root_init()->proc_net_init(), with net_ns_init()->setup_net(&init_net, &init_user_ns) also occuring in boot time from the same init_task. When there are no another tasks to race with them, for the single task it does not matter, which order two sequential independent loads should be made. So we make them reordered. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-25net: Move net:netns_ids destruction out of rtnl_lock() and document locking schemeKirill Tkhai1-18/+44
Currently, we unhash a dying net from netns_ids lists under rtnl_lock(). It's a leftover from the time when net::netns_ids was introduced. There was no net::nsid_lock, and rtnl_lock() was mostly need to order modification of alive nets nsid idr, i.e. for: for_each_net(tmp) { ... id = __peernet2id(tmp, net); idr_remove(&tmp->netns_ids, id); ... } Since we have net::nsid_lock, the modifications are protected by this local lock, and now we may introduce better scheme of netns_ids destruction. Let's look at the functions peernet2id_alloc() and get_net_ns_by_id(). Previous commits taught these functions to work well with dying net acquired from rtnl unlocked lists. And they are the only functions which can hash a net to netns_ids or obtain from there. And as easy to check, other netns_ids operating functions works with id, not with net pointers. So, we do not need rtnl_lock to synchronize cleanup_net() with all them. The another property, which is used in the patch, is that net is unhashed from net_namespace_list in the only place and by the only process. So, we avoid excess rcu_read_lock() or rtnl_lock(), when we'are iterating over the list in unhash_nsid(). All the above makes possible to keep rtnl_lock() locked only for net->list deletion, and completely avoid it for netns_ids unhashing and destruction. As these two doings may take long time (e.g., memory allocation to send skb), the patch should positively act on the scalability and signify decrease the time, which rtnl_lock() is held in cleanup_net(). Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-17net: Remove spinlock from get_net_ns_by_id()Kirill Tkhai1-2/+0
idr_find() is safe under rcu_read_lock() and maybe_get_net() guarantees that net is alive. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-17net: Fix possible race in peernet2id_alloc()Kirill Tkhai1-2/+11
peernet2id_alloc() is racy without rtnl_lock() as refcount_read(&peer->count) under net->nsid_lock does not guarantee, peer is alive: rcu_read_lock() peernet2id_alloc() .. spin_lock_bh(&net->nsid_lock) .. refcount_read(&peer->count) (!= 0) .. .. put_net() .. cleanup_net() .. for_each_net(tmp) .. spin_lock_bh(&tmp->nsid_lock) .. __peernet2id(tmp, net) == -1 .. .. .. .. __peernet2id_alloc(alloc == true) .. .. .. rcu_read_unlock() .. .. synchronize_rcu() .. kmem_cache_free(net) After the above situation, net::netns_id contains id pointing to freed memory, and any other dereferencing by the id will operate with this freed memory. Currently, peernet2id_alloc() is used under rtnl_lock() everywhere except ovs_vport_cmd_fill_info(), and this race can't occur. But peernet2id_alloc() is generic interface, and better we fix it before someone really starts use it in wrong context. v2: Don't place refcount_read(&net->count) under net->nsid_lock as suggested by Eric W. Biederman <ebiederm@xmission.com> v3: Rebase on top of net-next Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-15net: Convert atomic_t net::count to refcount_tKirill Tkhai1-4/+4
Since net could be obtained from RCU lists, and there is a race with net destruction, the patch converts net::count to refcount_t. This provides sanity checks for the cases of incrementing counter of already dead net, when maybe_get_net() has to used instead of get_net(). Drivers: allyesconfig and allmodconfig are OK. Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-20net: Fix double free and memory corruption in get_net_ns_by_id()Eric W. Biederman1-1/+1
(I can trivially verify that that idr_remove in cleanup_net happens after the network namespace count has dropped to zero --EWB) Function get_net_ns_by_id() does not check for net::count after it has found a peer in netns_ids idr. It may dereference a peer, after its count has already been finaly decremented. This leads to double free and memory corruption: put_net(peer) rtnl_lock() atomic_dec_and_test(&peer->count) [count=0] ... __put_net(peer) get_net_ns_by_id(net, id) spin_lock(&cleanup_list_lock) list_add(&net->cleanup_list, &cleanup_list) spin_unlock(&cleanup_list_lock) queue_work() peer = idr_find(&net->netns_ids, id) | get_net(peer) [count=1] | ... | (use after final put) v ... cleanup_net() ... spin_lock(&cleanup_list_lock) ... list_replace_init(&cleanup_list, ..) ... spin_unlock(&cleanup_list_lock) ... ... ... ... put_net(peer) ... atomic_dec_and_test(&peer->count) [count=0] ... spin_lock(&cleanup_list_lock) ... list_add(&net->cleanup_list, &cleanup_list) ... spin_unlock(&cleanup_list_lock) ... queue_work() ... rtnl_unlock() rtnl_lock() ... for_each_net(tmp) { ... id = __peernet2id(tmp, peer) ... spin_lock_irq(&tmp->nsid_lock) ... idr_remove(&tmp->netns_ids, id) ... ... ... net_drop_ns() ... net_free(peer) ... } ... | v cleanup_net() ... (Second free of peer) Also, put_net() on the right cpu may reorder with left's cpu list_replace_init(&cleanup_list, ..), and then cleanup_list will be corrupted. Since cleanup_net() is executed in worker thread, while put_net(peer) can happen everywhere, there should be enough time for concurrent get_net_ns_by_id() to pick the peer up, and the race does not seem to be unlikely. The patch fixes the problem in standard way. (Also, there is possible problem in peernet2id_alloc(), which requires check for net::count under nsid_lock and maybe_get_net(peer), but in current stable kernel it's used under rtnl_lock() and it has to be safe. Openswitch begun to use peernet2id_alloc(), and possibly it should be fixed too. While this is not in stable kernel yet, so I'll send a separate message to netdev@ later). Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Fixes: 0c7aecd4bde4 "netns: add rtnl cmd to add and get peer netns ids" Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05net: export peernet2id_allocJiri Benc1-0/+1
It will be used by openvswitch. Signed-off-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-09net: call newid/getid without rtnl mutex heldFlorian Westphal1-2/+3
Both functions take nsid_lock and don't rely on rtnl lock. Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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