Commit Graph

13153 Commits

Author SHA1 Message Date
Eric Dumazet 1b53d64435 net: fix data-race in neigh_event_send()
KCSAN reported the following data-race [1]

The fix will also prevent the compiler from optimizing out
the condition.

[1]

BUG: KCSAN: data-race in neigh_resolve_output / neigh_resolve_output

write to 0xffff8880a41dba78 of 8 bytes by interrupt on cpu 1:
 neigh_event_send include/net/neighbour.h:443 [inline]
 neigh_resolve_output+0x78/0x480 net/core/neighbour.c:1474
 neigh_output include/net/neighbour.h:511 [inline]
 ip_finish_output2+0x4af/0xe40 net/ipv4/ip_output.c:228
 __ip_finish_output net/ipv4/ip_output.c:308 [inline]
 __ip_finish_output+0x23a/0x490 net/ipv4/ip_output.c:290
 ip_finish_output+0x41/0x160 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip_output+0xdf/0x210 net/ipv4/ip_output.c:432
 dst_output include/net/dst.h:436 [inline]
 ip_local_out+0x74/0x90 net/ipv4/ip_output.c:125
 __ip_queue_xmit+0x3a8/0xa40 net/ipv4/ip_output.c:532
 ip_queue_xmit+0x45/0x60 include/net/ip.h:237
 __tcp_transmit_skb+0xe81/0x1d60 net/ipv4/tcp_output.c:1169
 tcp_transmit_skb net/ipv4/tcp_output.c:1185 [inline]
 __tcp_retransmit_skb+0x4bd/0x15f0 net/ipv4/tcp_output.c:2976
 tcp_retransmit_skb+0x36/0x1a0 net/ipv4/tcp_output.c:2999
 tcp_retransmit_timer+0x719/0x16d0 net/ipv4/tcp_timer.c:515
 tcp_write_timer_handler+0x42d/0x510 net/ipv4/tcp_timer.c:598
 tcp_write_timer+0xd1/0xf0 net/ipv4/tcp_timer.c:618

read to 0xffff8880a41dba78 of 8 bytes by interrupt on cpu 0:
 neigh_event_send include/net/neighbour.h:442 [inline]
 neigh_resolve_output+0x57/0x480 net/core/neighbour.c:1474
 neigh_output include/net/neighbour.h:511 [inline]
 ip_finish_output2+0x4af/0xe40 net/ipv4/ip_output.c:228
 __ip_finish_output net/ipv4/ip_output.c:308 [inline]
 __ip_finish_output+0x23a/0x490 net/ipv4/ip_output.c:290
 ip_finish_output+0x41/0x160 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip_output+0xdf/0x210 net/ipv4/ip_output.c:432
 dst_output include/net/dst.h:436 [inline]
 ip_local_out+0x74/0x90 net/ipv4/ip_output.c:125
 __ip_queue_xmit+0x3a8/0xa40 net/ipv4/ip_output.c:532
 ip_queue_xmit+0x45/0x60 include/net/ip.h:237
 __tcp_transmit_skb+0xe81/0x1d60 net/ipv4/tcp_output.c:1169
 tcp_transmit_skb net/ipv4/tcp_output.c:1185 [inline]
 __tcp_retransmit_skb+0x4bd/0x15f0 net/ipv4/tcp_output.c:2976
 tcp_retransmit_skb+0x36/0x1a0 net/ipv4/tcp_output.c:2999
 tcp_retransmit_timer+0x719/0x16d0 net/ipv4/tcp_timer.c:515
 tcp_write_timer_handler+0x42d/0x510 net/ipv4/tcp_timer.c:598

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-08 13:59:53 -08:00
Toke Høiland-Jørgensen 71e67c3bd1 net/fq_impl: Switch to kvmalloc() for memory allocation
The FQ implementation used by mac80211 allocates memory using kmalloc(),
which can fail; and Johannes reported that this actually happens in
practice.

To avoid this, switch the allocation to kvmalloc() instead; this also
brings fq_impl in line with all the FQ qdiscs.

Fixes: 557fc4a098 ("fq: add fair queuing framework")
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20191105155750.547379-1-toke@redhat.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-11-08 09:11:49 +01:00
David S. Miller 53ba60afb1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Missing register size validation in bitwise and cmp offloads.

2) Fix error code in ip_set_sockfn_get() when copy_to_user() fails,
   from Dan Carpenter.

3) Oneliner to copy MAC address in IPv6 hash:ip,mac sets, from
   Stefano Brivio.

4) Missing policy validation in ipset with NL_VALIDATE_STRICT,
   from Jozsef Kadlecsik.

5) Fix unaligned access to private data area of nf_tables instructions,
   from Lukas Wunner.

6) Relax check for object updates, reported as a regression by
   Eric Garver, patch from Fernando Fernandez Mancera.

7) Crash on ebtables dnat extension when used from the output path.
   From Florian Westphal.

8) Fix bogus EOPNOTSUPP when updating basechain flags.

9) Fix bogus EBUSY when updating a basechain that is already offloaded.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-06 21:16:55 -08:00
Jakub Kicinski 79ffe6087e net/tls: add a TX lock
TLS TX needs to release and re-acquire the socket lock if send buffer
fills up.

TLS SW TX path currently depends on only allowing one thread to enter
the function by the abuse of sk_write_pending. If another writer is
already waiting for memory no new ones are allowed in.

This has two problems:
 - writers don't wake other threads up when they leave the kernel;
   meaning that this scheme works for single extra thread (second
   application thread or delayed work) because memory becoming
   available will send a wake up request, but as Mallesham and
   Pooja report with larger number of threads it leads to threads
   being put to sleep indefinitely;
 - the delayed work does not get _scheduled_ but it may _run_ when
   other writers are present leading to crashes as writers don't
   expect state to change under their feet (same records get pushed
   and freed multiple times); it's hard to reliably bail from the
   work, however, because the mere presence of a writer does not
   guarantee that the writer will push pending records before exiting.

Ensuring wakeups always happen will make the code basically open
code a mutex. Just use a mutex.

The TLS HW TX path does not have any locking (not even the
sk_write_pending hack), yet it uses a per-socket sg_tx_data
array to push records.

Fixes: a42055e8d2 ("net/tls: Add support for async encryption of records for performance")
Reported-by: Mallesham  Jatharakonda <mallesh537@gmail.com>
Reported-by: Pooja Trivedi <poojatrivedi@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-06 17:33:32 -08:00
Eric Dumazet f75359f3ac net: prevent load/store tearing on sk->sk_stamp
Add a couple of READ_ONCE() and WRITE_ONCE() to prevent
load-tearing and store-tearing in sock_read_timestamp()
and sock_write_timestamp()

This might prevent another KCSAN report.

Fixes: 3a0ed3e961 ("sock: Make sock->sk_stamp thread-safe")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-05 18:22:30 -08:00
John Hurley 59eb87cb52 net: sched: prevent duplicate flower rules from tcf_proto destroy race
When a new filter is added to cls_api, the function
tcf_chain_tp_insert_unique() looks up the protocol/priority/chain to
determine if the tcf_proto is duplicated in the chain's hashtable. It then
creates a new entry or continues with an existing one. In cls_flower, this
allows the function fl_ht_insert_unque to determine if a filter is a
duplicate and reject appropriately, meaning that the duplicate will not be
passed to drivers via the offload hooks. However, when a tcf_proto is
destroyed it is removed from its chain before a hardware remove hook is
hit. This can lead to a race whereby the driver has not received the
remove message but duplicate flows can be accepted. This, in turn, can
lead to the offload driver receiving incorrect duplicate flows and out of
order add/delete messages.

Prevent duplicates by utilising an approach suggested by Vlad Buslov. A
hash table per block stores each unique chain/protocol/prio being
destroyed. This entry is only removed when the full destroy (and hardware
offload) has completed. If a new flow is being added with the same
identiers as a tc_proto being detroyed, then the add request is replayed
until the destroy is complete.

Fixes: 8b64678e0a ("net: sched: refactor tp insert/delete for concurrent execution")
Signed-off-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reported-by: Louis Peens <louis.peens@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-05 17:47:26 -08:00
Jay Vosburgh 1899bb3251 bonding: fix state transition issue in link monitoring
Since de77ecd4ef ("bonding: improve link-status update in
mii-monitoring"), the bonding driver has utilized two separate variables
to indicate the next link state a particular slave should transition to.
Each is used to communicate to a different portion of the link state
change commit logic; one to the bond_miimon_commit function itself, and
another to the state transition logic.

	Unfortunately, the two variables can become unsynchronized,
resulting in incorrect link state transitions within bonding.  This can
cause slaves to become stuck in an incorrect link state until a
subsequent carrier state transition.

	The issue occurs when a special case in bond_slave_netdev_event
sets slave->link directly to BOND_LINK_FAIL.  On the next pass through
bond_miimon_inspect after the slave goes carrier up, the BOND_LINK_FAIL
case will set the proposed next state (link_new_state) to BOND_LINK_UP,
but the new_link to BOND_LINK_DOWN.  The setting of the final link state
from new_link comes after that from link_new_state, and so the slave
will end up incorrectly in _DOWN state.

	Resolve this by combining the two variables into one.

Reported-by: Aleksei Zakharov <zakharov.a.g@yandex.ru>
Reported-by: Sha Zhang <zhangsha.zhang@huawei.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Fixes: de77ecd4ef ("bonding: improve link-status update in mii-monitoring")
Signed-off-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-05 17:40:16 -08:00
Lukas Wunner 250367c59e netfilter: nf_tables: Align nft_expr private data to 64-bit
Invoking the following commands on a 32-bit architecture with strict
alignment requirements (such as an ARMv7-based Raspberry Pi) results
in an alignment exception:

 # nft add table ip test-ip4
 # nft add chain ip test-ip4 output { type filter hook output priority 0; }
 # nft add rule  ip test-ip4 output quota 1025 bytes

Alignment trap: not handling instruction e1b26f9f at [<7f4473f8>]
Unhandled fault: alignment exception (0x001) at 0xb832e824
Internal error: : 1 [#1] PREEMPT SMP ARM
Hardware name: BCM2835
[<7f4473fc>] (nft_quota_do_init [nft_quota])
[<7f447448>] (nft_quota_init [nft_quota])
[<7f4260d0>] (nf_tables_newrule [nf_tables])
[<7f4168dc>] (nfnetlink_rcv_batch [nfnetlink])
[<7f416bd0>] (nfnetlink_rcv [nfnetlink])
[<8078b334>] (netlink_unicast)
[<8078b664>] (netlink_sendmsg)
[<8071b47c>] (sock_sendmsg)
[<8071bd18>] (___sys_sendmsg)
[<8071ce3c>] (__sys_sendmsg)
[<8071ce94>] (sys_sendmsg)

The reason is that nft_quota_do_init() calls atomic64_set() on an
atomic64_t which is only aligned to 32-bit, not 64-bit, because it
succeeds struct nft_expr in memory which only contains a 32-bit pointer.
Fix by aligning the nft_expr private data to 64-bit.

Fixes: 96518518cc ("netfilter: add nftables")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-11-04 20:58:32 +01:00
Eric Dumazet ee8d153d46 net: annotate lockless accesses to sk->sk_napi_id
We already annotated most accesses to sk->sk_napi_id

We missed sk_mark_napi_id() and sk_mark_napi_id_once()
which might be called without socket lock held in UDP stack.

KCSAN reported :
BUG: KCSAN: data-race in udpv6_queue_rcv_one_skb / udpv6_queue_rcv_one_skb

write to 0xffff888121c6d108 of 4 bytes by interrupt on cpu 0:
 sk_mark_napi_id include/net/busy_poll.h:125 [inline]
 __udpv6_queue_rcv_skb net/ipv6/udp.c:571 [inline]
 udpv6_queue_rcv_one_skb+0x70c/0xb40 net/ipv6/udp.c:672
 udpv6_queue_rcv_skb+0xb5/0x400 net/ipv6/udp.c:689
 udp6_unicast_rcv_skb.isra.0+0xd7/0x180 net/ipv6/udp.c:832
 __udp6_lib_rcv+0x69c/0x1770 net/ipv6/udp.c:913
 udpv6_rcv+0x2b/0x40 net/ipv6/udp.c:1015
 ip6_protocol_deliver_rcu+0x22a/0xbe0 net/ipv6/ip6_input.c:409
 ip6_input_finish+0x30/0x50 net/ipv6/ip6_input.c:450
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip6_input+0x177/0x190 net/ipv6/ip6_input.c:459
 dst_input include/net/dst.h:442 [inline]
 ip6_rcv_finish+0x110/0x140 net/ipv6/ip6_input.c:76
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ipv6_rcv+0x1a1/0x1b0 net/ipv6/ip6_input.c:284
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
 process_backlog+0x1d3/0x420 net/core/dev.c:5955
 napi_poll net/core/dev.c:6392 [inline]
 net_rx_action+0x3ae/0xa90 net/core/dev.c:6460

write to 0xffff888121c6d108 of 4 bytes by interrupt on cpu 1:
 sk_mark_napi_id include/net/busy_poll.h:125 [inline]
 __udpv6_queue_rcv_skb net/ipv6/udp.c:571 [inline]
 udpv6_queue_rcv_one_skb+0x70c/0xb40 net/ipv6/udp.c:672
 udpv6_queue_rcv_skb+0xb5/0x400 net/ipv6/udp.c:689
 udp6_unicast_rcv_skb.isra.0+0xd7/0x180 net/ipv6/udp.c:832
 __udp6_lib_rcv+0x69c/0x1770 net/ipv6/udp.c:913
 udpv6_rcv+0x2b/0x40 net/ipv6/udp.c:1015
 ip6_protocol_deliver_rcu+0x22a/0xbe0 net/ipv6/ip6_input.c:409
 ip6_input_finish+0x30/0x50 net/ipv6/ip6_input.c:450
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip6_input+0x177/0x190 net/ipv6/ip6_input.c:459
 dst_input include/net/dst.h:442 [inline]
 ip6_rcv_finish+0x110/0x140 net/ipv6/ip6_input.c:76
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ipv6_rcv+0x1a1/0x1b0 net/ipv6/ip6_input.c:284
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
 process_backlog+0x1d3/0x420 net/core/dev.c:5955

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10890 Comm: syz-executor.0 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: e68b6e50fa ("udp: enable busy polling for all sockets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-30 17:34:35 -07:00
Eric Dumazet 7170a97774 net: annotate accesses to sk->sk_incoming_cpu
This socket field can be read and written by concurrent cpus.

Use READ_ONCE() and WRITE_ONCE() annotations to document this,
and avoid some compiler 'optimizations'.

KCSAN reported :

BUG: KCSAN: data-race in tcp_v4_rcv / tcp_v4_rcv

write to 0xffff88812220763c of 4 bytes by interrupt on cpu 0:
 sk_incoming_cpu_update include/net/sock.h:953 [inline]
 tcp_v4_rcv+0x1b3c/0x1bb0 net/ipv4/tcp_ipv4.c:1934
 ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
 process_backlog+0x1d3/0x420 net/core/dev.c:5955
 napi_poll net/core/dev.c:6392 [inline]
 net_rx_action+0x3ae/0xa90 net/core/dev.c:6460
 __do_softirq+0x115/0x33f kernel/softirq.c:292
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082
 do_softirq.part.0+0x6b/0x80 kernel/softirq.c:337
 do_softirq kernel/softirq.c:329 [inline]
 __local_bh_enable_ip+0x76/0x80 kernel/softirq.c:189

read to 0xffff88812220763c of 4 bytes by interrupt on cpu 1:
 sk_incoming_cpu_update include/net/sock.h:952 [inline]
 tcp_v4_rcv+0x181a/0x1bb0 net/ipv4/tcp_ipv4.c:1934
 ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
 process_backlog+0x1d3/0x420 net/core/dev.c:5955
 napi_poll net/core/dev.c:6392 [inline]
 net_rx_action+0x3ae/0xa90 net/core/dev.c:6460
 __do_softirq+0x115/0x33f kernel/softirq.c:292
 run_ksoftirqd+0x46/0x60 kernel/softirq.c:603
 smpboot_thread_fn+0x37d/0x4a0 kernel/smpboot.c:165

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-30 13:24:25 -07:00
Tejun Heo 20eb4f29b6 net: fix sk_page_frag() recursion from memory reclaim
sk_page_frag() optimizes skb_frag allocations by using per-task
skb_frag cache when it knows it's the only user.  The condition is
determined by seeing whether the socket allocation mask allows
blocking - if the allocation may block, it obviously owns the task's
context and ergo exclusively owns current->task_frag.

Unfortunately, this misses recursion through memory reclaim path.
Please take a look at the following backtrace.

 [2] RIP: 0010:tcp_sendmsg_locked+0xccf/0xe10
     ...
     tcp_sendmsg+0x27/0x40
     sock_sendmsg+0x30/0x40
     sock_xmit.isra.24+0xa1/0x170 [nbd]
     nbd_send_cmd+0x1d2/0x690 [nbd]
     nbd_queue_rq+0x1b5/0x3b0 [nbd]
     __blk_mq_try_issue_directly+0x108/0x1b0
     blk_mq_request_issue_directly+0xbd/0xe0
     blk_mq_try_issue_list_directly+0x41/0xb0
     blk_mq_sched_insert_requests+0xa2/0xe0
     blk_mq_flush_plug_list+0x205/0x2a0
     blk_flush_plug_list+0xc3/0xf0
 [1] blk_finish_plug+0x21/0x2e
     _xfs_buf_ioapply+0x313/0x460
     __xfs_buf_submit+0x67/0x220
     xfs_buf_read_map+0x113/0x1a0
     xfs_trans_read_buf_map+0xbf/0x330
     xfs_btree_read_buf_block.constprop.42+0x95/0xd0
     xfs_btree_lookup_get_block+0x95/0x170
     xfs_btree_lookup+0xcc/0x470
     xfs_bmap_del_extent_real+0x254/0x9a0
     __xfs_bunmapi+0x45c/0xab0
     xfs_bunmapi+0x15/0x30
     xfs_itruncate_extents_flags+0xca/0x250
     xfs_free_eofblocks+0x181/0x1e0
     xfs_fs_destroy_inode+0xa8/0x1b0
     destroy_inode+0x38/0x70
     dispose_list+0x35/0x50
     prune_icache_sb+0x52/0x70
     super_cache_scan+0x120/0x1a0
     do_shrink_slab+0x120/0x290
     shrink_slab+0x216/0x2b0
     shrink_node+0x1b6/0x4a0
     do_try_to_free_pages+0xc6/0x370
     try_to_free_mem_cgroup_pages+0xe3/0x1e0
     try_charge+0x29e/0x790
     mem_cgroup_charge_skmem+0x6a/0x100
     __sk_mem_raise_allocated+0x18e/0x390
     __sk_mem_schedule+0x2a/0x40
 [0] tcp_sendmsg_locked+0x8eb/0xe10
     tcp_sendmsg+0x27/0x40
     sock_sendmsg+0x30/0x40
     ___sys_sendmsg+0x26d/0x2b0
     __sys_sendmsg+0x57/0xa0
     do_syscall_64+0x42/0x100
     entry_SYSCALL_64_after_hwframe+0x44/0xa9

In [0], tcp_send_msg_locked() was using current->page_frag when it
called sk_wmem_schedule().  It already calculated how many bytes can
be fit into current->page_frag.  Due to memory pressure,
sk_wmem_schedule() called into memory reclaim path which called into
xfs and then IO issue path.  Because the filesystem in question is
backed by nbd, the control goes back into the tcp layer - back into
tcp_sendmsg_locked().

nbd sets sk_allocation to (GFP_NOIO | __GFP_MEMALLOC) which makes
sense - it's in the process of freeing memory and wants to be able to,
e.g., drop clean pages to make forward progress.  However, this
confused sk_page_frag() called from [2].  Because it only tests
whether the allocation allows blocking which it does, it now thinks
current->page_frag can be used again although it already was being
used in [0].

After [2] used current->page_frag, the offset would be increased by
the used amount.  When the control returns to [0],
current->page_frag's offset is increased and the previously calculated
number of bytes now may overrun the end of allocated memory leading to
silent memory corruptions.

Fix it by adding gfpflags_normal_context() which tests sleepable &&
!reclaim and use it to determine whether to use current->task_frag.

v2: Eric didn't like gfp flags being tested twice.  Introduce a new
    helper gfpflags_normal_context() and combine the two tests.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-28 16:17:31 -07:00
David S. Miller fc11078dd3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

====================
Netfilter/IPVS fixes for net

The following patchset contains Netfilter/IPVS fixes for net:

1) Fix crash on flowtable due to race between garbage collection
   and insertion.

2) Restore callback unbinding in netfilter offloads.

3) Fix races on IPVS module removal, from Davide Caratti.

4) Make old_secure_tcp per-netns to fix sysbot report,
   from Eric Dumazet.

5) Validate matching length in netfilter offloads, from wenxu.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-27 12:13:16 -07:00
Guillaume Nault d4e4fdf9e4 netns: fix GFP flags in rtnl_net_notifyid()
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: 9a9634545c ("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>
2019-10-25 20:14:42 -07:00
Ben Dooks (Codethink) 91e2e57636 net: hwbm: if CONFIG_NET_HWBM unset, make stub functions static
If CONFIG_NET_HWBM is not set, then these stub functions in
<net/hwbm.h> should be declared static to avoid trying to
export them from any driver that includes this.

Fixes the following sparse warnings:

./include/net/hwbm.h:24:6: warning: symbol 'hwbm_buf_free' was not declared. Should it be static?
./include/net/hwbm.h:25:5: warning: symbol 'hwbm_pool_refill' was not declared. Should it be static?
./include/net/hwbm.h:26:5: warning: symbol 'hwbm_pool_add' was not declared. Should it be static?

Signed-off-by: Ben Dooks (Codethink) <ben.dooks@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-25 16:24:32 -07:00
Taehee Yoo f3b0a18bb6 net: remove unnecessary variables and callback
This patch removes variables and callback these are related to the nested
device structure.
devices that can be nested have their own nest_level variable that
represents the depth of nested devices.
In the previous patch, new {lower/upper}_level variables are added and
they replace old private nest_level variable.
So, this patch removes all 'nest_level' variables.

In order to avoid lockdep warning, ->ndo_get_lock_subclass() was added
to get lockdep subclass value, which is actually lower nested depth value.
But now, they use the dynamic lockdep key to avoid lockdep warning instead
of the subclass.
So, this patch removes ->ndo_get_lock_subclass() callback.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-24 14:53:49 -07:00
Taehee Yoo 0ce1822c2a vxlan: add adjacent link to limit depth level
Current vxlan code doesn't limit the number of nested devices.
Nested devices would be handled recursively and this routine needs
huge stack memory. So, unlimited nested devices could make
stack overflow.

In order to fix this issue, this patch adds adjacent links.
The adjacent link APIs internally check the depth level.

Test commands:
    ip link add dummy0 type dummy
    ip link add vxlan0 type vxlan id 0 group 239.1.1.1 dev dummy0 \
	    dstport 4789
    for i in {1..100}
    do
	    let A=$i-1
	    ip link add vxlan$i type vxlan id $i group 239.1.1.1 \
		    dev vxlan$A dstport 4789
    done
    ip link del dummy0

The top upper link is vxlan100 and the lowest link is vxlan0.
When vxlan0 is deleting, the upper devices will be deleted recursively.
It needs huge stack memory so it makes stack overflow.

Splat looks like:
[  229.628477] =============================================================================
[  229.629785] BUG page->ptl (Not tainted): Padding overwritten. 0x0000000026abf214-0x0000000091f6abb2
[  229.629785] -----------------------------------------------------------------------------
[  229.629785]
[  229.655439] ==================================================================
[  229.629785] INFO: Slab 0x00000000ff7cfda8 objects=19 used=19 fp=0x00000000fe33776c flags=0x200000000010200
[  229.655688] BUG: KASAN: stack-out-of-bounds in unmap_single_vma+0x25a/0x2e0
[  229.655688] Read of size 8 at addr ffff888113076928 by task vlan-network-in/2334
[  229.655688]
[  229.629785] Padding 0000000026abf214: 00 80 14 0d 81 88 ff ff 68 91 81 14 81 88 ff ff  ........h.......
[  229.629785] Padding 0000000001e24790: 38 91 81 14 81 88 ff ff 68 91 81 14 81 88 ff ff  8.......h.......
[  229.629785] Padding 00000000b39397c8: 33 30 62 a7 ff ff ff ff ff eb 60 22 10 f1 ff 1f  30b.......`"....
[  229.629785] Padding 00000000bc98f53a: 80 60 07 13 81 88 ff ff 00 80 14 0d 81 88 ff ff  .`..............
[  229.629785] Padding 000000002aa8123d: 68 91 81 14 81 88 ff ff f7 21 17 a7 ff ff ff ff  h........!......
[  229.629785] Padding 000000001c8c2369: 08 81 14 0d 81 88 ff ff 03 02 00 00 00 00 00 00  ................
[  229.629785] Padding 000000004e290c5d: 21 90 a2 21 10 ed ff ff 00 00 00 00 00 fc ff df  !..!............
[  229.629785] Padding 000000000e25d731: 18 60 07 13 81 88 ff ff c0 8b 13 05 81 88 ff ff  .`..............
[  229.629785] Padding 000000007adc7ab3: b3 8a b5 41 00 00 00 00                          ...A....
[  229.629785] FIX page->ptl: Restoring 0x0000000026abf214-0x0000000091f6abb2=0x5a
[  ... ]

Fixes: acaf4e7099 ("net: vxlan: when lower dev unregisters remove vxlan dev as well")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-24 14:53:49 -07:00
Taehee Yoo 089bca2cae bonding: use dynamic lockdep key instead of subclass
All bonding device has same lockdep key and subclass is initialized with
nest_level.
But actual nest_level value can be changed when a lower device is attached.
And at this moment, the subclass should be updated but it seems to be
unsafe.
So this patch makes bonding use dynamic lockdep key instead of the
subclass.

Test commands:
    ip link add bond0 type bond

    for i in {1..5}
    do
	    let A=$i-1
	    ip link add bond$i type bond
	    ip link set bond$i master bond$A
    done
    ip link set bond5 master bond0

Splat looks like:
[  307.992912] WARNING: possible recursive locking detected
[  307.993656] 5.4.0-rc3+ #96 Tainted: G        W
[  307.994367] --------------------------------------------
[  307.995092] ip/761 is trying to acquire lock:
[  307.995710] ffff8880513aac60 (&(&bond->stats_lock)->rlock#2/2){+.+.}, at: bond_get_stats+0xb8/0x500 [bonding]
[  307.997045]
	       but task is already holding lock:
[  307.997923] ffff88805fcbac60 (&(&bond->stats_lock)->rlock#2/2){+.+.}, at: bond_get_stats+0xb8/0x500 [bonding]
[  307.999215]
	       other info that might help us debug this:
[  308.000251]  Possible unsafe locking scenario:

[  308.001137]        CPU0
[  308.001533]        ----
[  308.001915]   lock(&(&bond->stats_lock)->rlock#2/2);
[  308.002609]   lock(&(&bond->stats_lock)->rlock#2/2);
[  308.003302]
		*** DEADLOCK ***

[  308.004310]  May be due to missing lock nesting notation

[  308.005319] 3 locks held by ip/761:
[  308.005830]  #0: ffffffff9fcc42b0 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x466/0x8a0
[  308.006894]  #1: ffff88805fcbac60 (&(&bond->stats_lock)->rlock#2/2){+.+.}, at: bond_get_stats+0xb8/0x500 [bonding]
[  308.008243]  #2: ffffffff9f9219c0 (rcu_read_lock){....}, at: bond_get_stats+0x9f/0x500 [bonding]
[  308.009422]
	       stack backtrace:
[  308.010124] CPU: 0 PID: 761 Comm: ip Tainted: G        W         5.4.0-rc3+ #96
[  308.011097] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[  308.012179] Call Trace:
[  308.012601]  dump_stack+0x7c/0xbb
[  308.013089]  __lock_acquire+0x269d/0x3de0
[  308.013669]  ? register_lock_class+0x14d0/0x14d0
[  308.014318]  lock_acquire+0x164/0x3b0
[  308.014858]  ? bond_get_stats+0xb8/0x500 [bonding]
[  308.015520]  _raw_spin_lock_nested+0x2e/0x60
[  308.016129]  ? bond_get_stats+0xb8/0x500 [bonding]
[  308.017215]  bond_get_stats+0xb8/0x500 [bonding]
[  308.018454]  ? bond_arp_rcv+0xf10/0xf10 [bonding]
[  308.019710]  ? rcu_read_lock_held+0x90/0xa0
[  308.020605]  ? rcu_read_lock_sched_held+0xc0/0xc0
[  308.021286]  ? bond_get_stats+0x9f/0x500 [bonding]
[  308.021953]  dev_get_stats+0x1ec/0x270
[  308.022508]  bond_get_stats+0x1d1/0x500 [bonding]

Fixes: d3fff6c443 ("net: add netdev_lockdep_set_classes() helper")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-24 14:53:48 -07:00
Eric Dumazet c24b75e0f9 ipvs: move old_secure_tcp into struct netns_ipvs
syzbot reported the following issue :

BUG: KCSAN: data-race in update_defense_level / update_defense_level

read to 0xffffffff861a6260 of 4 bytes by task 3006 on cpu 1:
 update_defense_level+0x621/0xb30 net/netfilter/ipvs/ip_vs_ctl.c:177
 defense_work_handler+0x3d/0xd0 net/netfilter/ipvs/ip_vs_ctl.c:225
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

write to 0xffffffff861a6260 of 4 bytes by task 7333 on cpu 0:
 update_defense_level+0xa62/0xb30 net/netfilter/ipvs/ip_vs_ctl.c:205
 defense_work_handler+0x3d/0xd0 net/netfilter/ipvs/ip_vs_ctl.c:225
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7333 Comm: kworker/0:5 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events defense_work_handler

Indeed, old_secure_tcp is currently a static variable, while it
needs to be a per netns variable.

Fixes: a0840e2e16 ("IPVS: netns, ip_vs_ctl local vars moved to ipvs struct.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
2019-10-24 11:56:02 +02:00
Eric Dumazet 55667441c8 net/flow_dissector: switch to siphash
UDP IPv6 packets auto flowlabels are using a 32bit secret
(static u32 hashrnd in net/core/flow_dissector.c) and
apply jhash() over fields known by the receivers.

Attackers can easily infer the 32bit secret and use this information
to identify a device and/or user, since this 32bit secret is only
set at boot time.

Really, using jhash() to generate cookies sent on the wire
is a serious security concern.

Trying to change the rol32(hash, 16) in ip6_make_flowlabel() would be
a dead end. Trying to periodically change the secret (like in sch_sfq.c)
could change paths taken in the network for long lived flows.

Let's switch to siphash, as we did in commit df453700e8
("inet: switch IP ID generator to siphash")

Using a cryptographically strong pseudo random function will solve this
privacy issue and more generally remove other weak points in the stack.

Packet schedulers using skb_get_hash_perturb() benefit from this change.

Fixes: b56774163f ("ipv6: Enable auto flow labels by default")
Fixes: 42240901f7 ("ipv6: Implement different admin modes for automatic flow labels")
Fixes: 67800f9b1f ("ipv6: Call skb_get_hash_flowi6 to get skb->hash in ip6_make_flowlabel")
Fixes: cb1ce2ef38 ("ipv6: Implement automatic flow label generation on transmit")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jonathan Berger <jonathann1@walla.com>
Reported-by: Amit Klein <aksecurity@gmail.com>
Reported-by: Benny Pinkas <benny@pinkas.net>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-23 20:13:22 -07:00
Eric Dumazet e7a409c3f4 ipv4: fix IPSKB_FRAG_PMTU handling with fragmentation
This patch removes the iph field from the state structure, which is not
properly initialized. Instead, add a new field to make the "do we want
to set DF" be the state bit and move the code to set the DF flag from
ip_frag_next().

Joint work with Pablo and Linus.

Fixes: 19c3401a91 ("net: ipv4: place control buffer handling away from fragmentation iterators")
Reported-by: Patrick Schönthaler <patrick@notvads.ovh>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-21 10:46:42 -07:00
Eric Dumazet 2a06b8982f net: reorder 'struct net' fields to avoid false sharing
Intel test robot reported a ~7% regression on TCP_CRR tests
that they bisected to the cited commit.

Indeed, every time a new TCP socket is created or deleted,
the atomic counter net->count is touched (via get_net(net)
and put_net(net) calls)

So cpus might have to reload a contended cache line in
net_hash_mix(net) calls.

We need to reorder 'struct net' fields to move @hash_mix
in a read mostly cache line.

We move in the first cache line fields that can be
dirtied often.

We probably will have to address in a followup patch
the __randomize_layout that was added in linux-4.13,
since this might break our placement choices.

Fixes: 355b985537 ("netns: provide pure entropy for net_hash_mix()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-19 12:21:53 -07:00
Eric Dumazet ab4e846a82 tcp: annotate sk->sk_wmem_queued lockless reads
For the sake of tcp_poll(), there are few places where we fetch
sk->sk_wmem_queued while this field can change from IRQ or other cpu.

We need to add READ_ONCE() annotations, and also make sure write
sides use corresponding WRITE_ONCE() to avoid store-tearing.

sk_wmem_queued_add() helper is added so that we can in
the future convert to ADD_ONCE() or equivalent if/when
available.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-13 10:13:08 -07:00
Eric Dumazet e292f05e0d tcp: annotate sk->sk_sndbuf lockless reads
For the sake of tcp_poll(), there are few places where we fetch
sk->sk_sndbuf while this field can change from IRQ or other cpu.

We need to add READ_ONCE() annotations, and also make sure write
sides use corresponding WRITE_ONCE() to avoid store-tearing.

Note that other transports probably need similar fixes.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-13 10:13:08 -07:00
Eric Dumazet ebb3b78db7 tcp: annotate sk->sk_rcvbuf lockless reads
For the sake of tcp_poll(), there are few places where we fetch
sk->sk_rcvbuf while this field can change from IRQ or other cpu.

We need to add READ_ONCE() annotations, and also make sure write
sides use corresponding WRITE_ONCE() to avoid store-tearing.

Note that other transports probably need similar fixes.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-13 10:13:08 -07:00
Eric Dumazet e0d694d638 tcp: annotate tp->snd_nxt lockless reads
There are few places where we fetch tp->snd_nxt while
this field can change from IRQ or other cpu.

We need to add READ_ONCE() annotations, and also make
sure write sides use corresponding WRITE_ONCE() to avoid
store-tearing.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-13 10:13:08 -07:00