linux-stable.git/net, branch v4.19.63

hvsock: fix epollout hang from race condition

2019-07-31T05:26:56+00:00

[ Upstream commit cb359b60416701c8bed82fec79de25a144beb893 ]

Currently, hvsock can enter into a state where epoll_wait on EPOLLOUT will
not return even when the hvsock socket is writable, under some race
condition. This can happen under the following sequence:
- fd = socket(hvsocket)
- fd_out = dup(fd)
- fd_in = dup(fd)
- start a writer thread that writes data to fd_out with a combination of
  epoll_wait(fd_out, EPOLLOUT) and
- start a reader thread that reads data from fd_in with a combination of
  epoll_wait(fd_in, EPOLLIN)
- On the host, there are two threads that are reading/writing data to the
  hvsocket

stack:
hvs_stream_has_space
hvs_notify_poll_out
vsock_poll
sock_poll
ep_poll

Race condition:
check for epollout from ep_poll():
	assume no writable space in the socket
	hvs_stream_has_space() returns 0
check for epollin from ep_poll():
	assume socket has some free space < HVS_PKT_LEN(HVS_SEND_BUF_SIZE)
	hvs_stream_has_space() will clear the channel pending send size
	host will not notify the guest because the pending send size has
		been cleared and so the hvsocket will never mark the
		socket writable

Now, the EPOLLOUT will never return even if the socket write buffer is
empty.

The fix is to set the pending size to the default size and never change it.
This way the host will always notify the guest whenever the writable space
is bigger than the pending size. The host is already optimized to *only*
notify the guest when the pending size threshold boundary is crossed and
not everytime.

This change also reduces the cpu usage somewhat since hv_stream_has_space()
is in the hotpath of send:
vsock_stream_sendmsg()->hv_stream_has_space()
Earlier hv_stream_has_space was setting/clearing the pending size on every
call.

Signed-off-by: Sunil Muthuswamy 
Reviewed-by: Dexuan Cui 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: sched: verify that q!=NULL before setting q->flags

2019-07-28T06:29:30+00:00

commit 503d81d428bd598430f7f9d02021634e1a8139a0 upstream.

In function int tc_new_tfilter() q pointer can be NULL when adding filter
on a shared block. With recent change that resets TCQ_F_CAN_BYPASS after
filter creation, following NULL pointer dereference happens in case parent
block is shared:

[  212.925060] BUG: kernel NULL pointer dereference, address: 0000000000000010
[  212.925445] #PF: supervisor write access in kernel mode
[  212.925709] #PF: error_code(0x0002) - not-present page
[  212.925965] PGD 8000000827923067 P4D 8000000827923067 PUD 827924067 PMD 0
[  212.926302] Oops: 0002 [#1] SMP KASAN PTI
[  212.926539] CPU: 18 PID: 2617 Comm: tc Tainted: G    B             5.2.0+ #512
[  212.926938] Hardware name: Supermicro SYS-2028TP-DECR/X10DRT-P, BIOS 2.0b 03/30/2017
[  212.927364] RIP: 0010:tc_new_tfilter+0x698/0xd40
[  212.927633] Code: 74 0d 48 85 c0 74 08 48 89 ef e8 03 aa 62 00 48 8b 84 24 a0 00 00 00 48 8d 78 10 48 89 44 24 18 e8 4d 0c 6b ff 48 8b 44 24 18 <83> 60 10 f
b 48 85 ed 0f 85 3d fe ff ff e9 4f fe ff ff e8 81 26 f8
[  212.928607] RSP: 0018:ffff88884fd5f5d8 EFLAGS: 00010296
[  212.928905] RAX: 0000000000000000 RBX: 0000000000000000 RCX: dffffc0000000000
[  212.929201] RDX: 0000000000000007 RSI: 0000000000000004 RDI: 0000000000000297
[  212.929402] RBP: ffff88886bedd600 R08: ffffffffb91d4b51 R09: fffffbfff7616e4d
[  212.929609] R10: fffffbfff7616e4c R11: ffffffffbb0b7263 R12: ffff88886bc61040
[  212.929803] R13: ffff88884fd5f950 R14: ffffc900039c5000 R15: ffff88835e927680
[  212.929999] FS:  00007fe7c50b6480(0000) GS:ffff88886f980000(0000) knlGS:0000000000000000
[  212.930235] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  212.930394] CR2: 0000000000000010 CR3: 000000085bd04002 CR4: 00000000001606e0
[  212.930588] Call Trace:
[  212.930682]  ? tc_del_tfilter+0xa40/0xa40
[  212.930811]  ? __lock_acquire+0x5b5/0x2460
[  212.930948]  ? find_held_lock+0x85/0xa0
[  212.931081]  ? tc_del_tfilter+0xa40/0xa40
[  212.931201]  rtnetlink_rcv_msg+0x4ab/0x5f0
[  212.931332]  ? rtnl_dellink+0x490/0x490
[  212.931454]  ? lockdep_hardirqs_on+0x260/0x260
[  212.931589]  ? netlink_deliver_tap+0xab/0x5a0
[  212.931717]  ? match_held_lock+0x1b/0x240
[  212.931844]  netlink_rcv_skb+0xd0/0x200
[  212.931958]  ? rtnl_dellink+0x490/0x490
[  212.932079]  ? netlink_ack+0x440/0x440
[  212.932205]  ? netlink_deliver_tap+0x161/0x5a0
[  212.932335]  ? lock_downgrade+0x360/0x360
[  212.932457]  ? lock_acquire+0xe5/0x210
[  212.932579]  netlink_unicast+0x296/0x350
[  212.932705]  ? netlink_attachskb+0x390/0x390
[  212.932834]  ? _copy_from_iter_full+0xe0/0x3a0
[  212.932976]  netlink_sendmsg+0x394/0x600
[  212.937998]  ? netlink_unicast+0x350/0x350
[  212.943033]  ? move_addr_to_kernel.part.0+0x90/0x90
[  212.948115]  ? netlink_unicast+0x350/0x350
[  212.953185]  sock_sendmsg+0x96/0xa0
[  212.958099]  ___sys_sendmsg+0x482/0x520
[  212.962881]  ? match_held_lock+0x1b/0x240
[  212.967618]  ? copy_msghdr_from_user+0x250/0x250
[  212.972337]  ? lock_downgrade+0x360/0x360
[  212.976973]  ? rwlock_bug.part.0+0x60/0x60
[  212.981548]  ? __mod_node_page_state+0x1f/0xa0
[  212.986060]  ? match_held_lock+0x1b/0x240
[  212.990567]  ? find_held_lock+0x85/0xa0
[  212.994989]  ? do_user_addr_fault+0x349/0x5b0
[  212.999387]  ? lock_downgrade+0x360/0x360
[  213.003713]  ? find_held_lock+0x85/0xa0
[  213.007972]  ? __fget_light+0xa1/0xf0
[  213.012143]  ? sockfd_lookup_light+0x91/0xb0
[  213.016165]  __sys_sendmsg+0xba/0x130
[  213.020040]  ? __sys_sendmsg_sock+0xb0/0xb0
[  213.023870]  ? handle_mm_fault+0x337/0x470
[  213.027592]  ? page_fault+0x8/0x30
[  213.031316]  ? lockdep_hardirqs_off+0xbe/0x100
[  213.034999]  ? mark_held_locks+0x24/0x90
[  213.038671]  ? do_syscall_64+0x1e/0xe0
[  213.042297]  do_syscall_64+0x74/0xe0
[  213.045828]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  213.049354] RIP: 0033:0x7fe7c527c7b8
[  213.052792] Code: 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 8d 05 65 8f 0c 00 8b 00 85 c0 75 17 b8 2e 00 00 00 0f 05 <48> 3d 00 f
0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 89 54
[  213.060269] RSP: 002b:00007ffc3f7908a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  213.064144] RAX: ffffffffffffffda RBX: 000000005d34716f RCX: 00007fe7c527c7b8
[  213.068094] RDX: 0000000000000000 RSI: 00007ffc3f790910 RDI: 0000000000000003
[  213.072109] RBP: 0000000000000000 R08: 0000000000000001 R09: 00007fe7c5340cc0
[  213.076113] R10: 0000000000404ec2 R11: 0000000000000246 R12: 0000000000000080
[  213.080146] R13: 0000000000480640 R14: 0000000000000080 R15: 0000000000000000
[  213.084147] Modules linked in: act_gact cls_flower sch_ingress nfsv3 nfs_acl nfs lockd grace fscache bridge stp llc sunrpc intel_rapl_msr intel_rapl_common
[<1;69;32Msb_edac rdma_ucm rdma_cm x86_pkg_temp_thermal iw_cm intel_powerclamp ib_cm coretemp kvm_intel kvm irqbypass mlx5_ib ib_uverbs ib_core crct10dif_pclmul crc32_pc
lmul crc32c_intel ghash_clmulni_intel mlx5_core intel_cstate intel_uncore iTCO_wdt igb iTCO_vendor_support mlxfw mei_me ptp ses intel_rapl_perf mei pcspkr ipmi
_ssif i2c_i801 joydev enclosure pps_core lpc_ich ioatdma wmi dca ipmi_si ipmi_devintf ipmi_msghandler acpi_power_meter acpi_pad ast i2c_algo_bit drm_vram_helpe
r ttm drm_kms_helper drm mpt3sas raid_class scsi_transport_sas
[  213.112326] CR2: 0000000000000010
[  213.117429] ---[ end trace adb58eb0a4ee6283 ]---

Verify that q pointer is not NULL before setting the 'flags' field.

Fixes: 3f05e6886a59 ("net_sched: unset TCQ_F_CAN_BYPASS when adding filters")
Signed-off-by: Vlad Buslov 
Acked-by: Jiri Pirko 
Signed-off-by: David S. Miller 
Cc: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

net: bridge: stp: don't cache eth dest pointer before skb pull

2019-07-28T06:29:27+00:00

[ Upstream commit 2446a68ae6a8cee6d480e2f5b52f5007c7c41312 ]

Don't cache eth dest pointer before calling pskb_may_pull.

Fixes: cf0f02d04a83 ("[BRIDGE]: use llc for receiving STP packets")
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: bridge: don't cache ether dest pointer on input

2019-07-28T06:29:27+00:00

[ Upstream commit 3d26eb8ad1e9b906433903ce05f775cf038e747f ]

We would cache ether dst pointer on input in br_handle_frame_finish but
after the neigh suppress code that could lead to a stale pointer since
both ipv4 and ipv6 suppress code do pskb_may_pull. This means we have to
always reload it after the suppress code so there's no point in having
it cached just retrieve it directly.

Fixes: 057658cb33fbf ("bridge: suppress arp pkts on BR_NEIGH_SUPPRESS ports")
Fixes: ed842faeb2bd ("bridge: suppress nd pkts on BR_NEIGH_SUPPRESS ports")
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: bridge: mcast: fix stale ipv6 hdr pointer when handling v6 query

2019-07-28T06:29:27+00:00

[ Upstream commit 3b26a5d03d35d8f732d75951218983c0f7f68dff ]

We get a pointer to the ipv6 hdr in br_ip6_multicast_query but we may
call pskb_may_pull afterwards and end up using a stale pointer.
So use the header directly, it's just 1 place where it's needed.

Fixes: 08b202b67264 ("bridge br_multicast: IPv6 MLD support.")
Signed-off-by: Nikolay Aleksandrov 
Tested-by: Martin Weinelt 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: bridge: mcast: fix stale nsrcs pointer in igmp3/mld2 report handling

2019-07-28T06:29:27+00:00

[ Upstream commit e57f61858b7cf478ed6fa23ed4b3876b1c9625c4 ]

We take a pointer to grec prior to calling pskb_may_pull and use it
afterwards to get nsrcs so record nsrcs before the pull when handling
igmp3 and we get a pointer to nsrcs and call pskb_may_pull when handling
mld2 which again could lead to reading 2 bytes out-of-bounds.

 ==================================================================
 BUG: KASAN: use-after-free in br_multicast_rcv+0x480c/0x4ad0 [bridge]
 Read of size 2 at addr ffff8880421302b4 by task ksoftirqd/1/16

 CPU: 1 PID: 16 Comm: ksoftirqd/1 Tainted: G           OE     5.2.0-rc6+ #1
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
 Call Trace:
  dump_stack+0x71/0xab
  print_address_description+0x6a/0x280
  ? br_multicast_rcv+0x480c/0x4ad0 [bridge]
  __kasan_report+0x152/0x1aa
  ? br_multicast_rcv+0x480c/0x4ad0 [bridge]
  ? br_multicast_rcv+0x480c/0x4ad0 [bridge]
  kasan_report+0xe/0x20
  br_multicast_rcv+0x480c/0x4ad0 [bridge]
  ? br_multicast_disable_port+0x150/0x150 [bridge]
  ? ktime_get_with_offset+0xb4/0x150
  ? __kasan_kmalloc.constprop.6+0xa6/0xf0
  ? __netif_receive_skb+0x1b0/0x1b0
  ? br_fdb_update+0x10e/0x6e0 [bridge]
  ? br_handle_frame_finish+0x3c6/0x11d0 [bridge]
  br_handle_frame_finish+0x3c6/0x11d0 [bridge]
  ? br_pass_frame_up+0x3a0/0x3a0 [bridge]
  ? virtnet_probe+0x1c80/0x1c80 [virtio_net]
  br_handle_frame+0x731/0xd90 [bridge]
  ? select_idle_sibling+0x25/0x7d0
  ? br_handle_frame_finish+0x11d0/0x11d0 [bridge]
  __netif_receive_skb_core+0xced/0x2d70
  ? virtqueue_get_buf_ctx+0x230/0x1130 [virtio_ring]
  ? do_xdp_generic+0x20/0x20
  ? virtqueue_napi_complete+0x39/0x70 [virtio_net]
  ? virtnet_poll+0x94d/0xc78 [virtio_net]
  ? receive_buf+0x5120/0x5120 [virtio_net]
  ? __netif_receive_skb_one_core+0x97/0x1d0
  __netif_receive_skb_one_core+0x97/0x1d0
  ? __netif_receive_skb_core+0x2d70/0x2d70
  ? _raw_write_trylock+0x100/0x100
  ? __queue_work+0x41e/0xbe0
  process_backlog+0x19c/0x650
  ? _raw_read_lock_irq+0x40/0x40
  net_rx_action+0x71e/0xbc0
  ? __switch_to_asm+0x40/0x70
  ? napi_complete_done+0x360/0x360
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70
  ? __schedule+0x85e/0x14d0
  __do_softirq+0x1db/0x5f9
  ? takeover_tasklets+0x5f0/0x5f0
  run_ksoftirqd+0x26/0x40
  smpboot_thread_fn+0x443/0x680
  ? sort_range+0x20/0x20
  ? schedule+0x94/0x210
  ? __kthread_parkme+0x78/0xf0
  ? sort_range+0x20/0x20
  kthread+0x2ae/0x3a0
  ? kthread_create_worker_on_cpu+0xc0/0xc0
  ret_from_fork+0x35/0x40

 The buggy address belongs to the page:
 page:ffffea0001084c00 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0
 flags: 0xffffc000000000()
 raw: 00ffffc000000000 ffffea0000cfca08 ffffea0001098608 0000000000000000
 raw: 0000000000000000 0000000000000003 00000000ffffff7f 0000000000000000
 page dumped because: kasan: bad access detected

 Memory state around the buggy address:
 ffff888042130180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888042130200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 > ffff888042130280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                     ^
 ffff888042130300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888042130380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ==================================================================
 Disabling lock debugging due to kernel taint

Fixes: bc8c20acaea1 ("bridge: multicast: treat igmpv3 report with INCLUDE and no sources as a leave")
Reported-by: Martin Weinelt 
Signed-off-by: Nikolay Aleksandrov 
Tested-by: Martin Weinelt 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sctp: not bind the socket in sctp_connect

2019-07-28T06:29:27+00:00

[ Upstream commit 9b6c08878e23adb7cc84bdca94d8a944b03f099e ]

Now when sctp_connect() is called with a wrong sa_family, it binds
to a port but doesn't set bp->port, then sctp_get_af_specific will
return NULL and sctp_connect() returns -EINVAL.

Then if sctp_bind() is called to bind to another port, the last
port it has bound will leak due to bp->port is NULL by then.

sctp_connect() doesn't need to bind ports, as later __sctp_connect
will do it if bp->port is NULL. So remove it from sctp_connect().
While at it, remove the unnecessary sockaddr.sa_family len check
as it's already done in sctp_inet_connect.

Fixes: 644fbdeacf1d ("sctp: fix the issue that flags are ignored when using kernel_connect")
Reported-by: syzbot+079bf326b38072f849d9@syzkaller.appspotmail.com
Signed-off-by: Xin Long 
Acked-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net/tls: make sure offload also gets the keys wiped

2019-07-28T06:29:27+00:00

[ Upstream commit acd3e96d53a24d219f720ed4012b62723ae05da1 ]

Commit 86029d10af18 ("tls: zero the crypto information from tls_context
before freeing") added memzero_explicit() calls to clear the key material
before freeing struct tls_context, but it missed tls_device.c has its
own way of freeing this structure. Replace the missing free.

Fixes: 86029d10af18 ("tls: zero the crypto information from tls_context before freeing")
Signed-off-by: Jakub Kicinski 
Reviewed-by: Dirk van der Merwe 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net_sched: unset TCQ_F_CAN_BYPASS when adding filters

2019-07-28T06:29:27+00:00

[ Upstream commit 3f05e6886a595c9a29a309c52f45326be917823c ]

For qdisc's that support TC filters and set TCQ_F_CAN_BYPASS,
notably fq_codel, it makes no sense to let packets bypass the TC
filters we setup in any scenario, otherwise our packets steering
policy could not be enforced.

This can be reproduced easily with the following script:

 ip li add dev dummy0 type dummy
 ifconfig dummy0 up
 tc qd add dev dummy0 root fq_codel
 tc filter add dev dummy0 parent 8001: protocol arp basic action mirred egress redirect dev lo
 tc filter add dev dummy0 parent 8001: protocol ip basic action mirred egress redirect dev lo
 ping -I dummy0 192.168.112.1

Without this patch, packets are sent directly to dummy0 without
hitting any of the filters. With this patch, packets are redirected
to loopback as expected.

This fix is not perfect, it only unsets the flag but does not set it back
because we have to save the information somewhere in the qdisc if we
really want that. Note, both fq_codel and sfq clear this flag in their
->bind_tcf() but this is clearly not sufficient when we don't use any
class ID.

Fixes: 23624935e0c4 ("net_sched: TCQ_F_CAN_BYPASS generalization")
Cc: Eric Dumazet 
Signed-off-by: Cong Wang 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

netrom: hold sock when setting skb->destructor

2019-07-28T06:29:27+00:00

[ Upstream commit 4638faac032756f7eab5524be7be56bee77e426b ]

sock_efree() releases the sock refcnt, if we don't hold this refcnt
when setting skb->destructor to it, the refcnt would not be balanced.
This leads to several bug reports from syzbot.

I have checked other users of sock_efree(), all of them hold the
sock refcnt.

Fixes: c8c8218ec5af ("netrom: fix a memory leak in nr_rx_frame()")
Reported-and-tested-by: 
Reported-and-tested-by: 
Reported-and-tested-by: 
Reported-and-tested-by: 
Cc: Ralf Baechle 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman