On some architectures, the MMU can be disabled, leading to access_ok()
becoming an empty macro that does not evaluate its size argument,
which in turn produces an unused-variable warning:

drivers/vhost/vhost.c:1191:9: error: unused variable 's' [-Werror,-Wunused-variable]
        size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;

Mark the variable as __maybe_unused to shut up that warning.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previous to commit 22b5c0b6 ("vsock/virtio: fix kernel panic
after device hot-unplug"), vsock_core_init() was called from
virtio_vsock_probe(). Now, virtio_transport_reset_no_sock() can be called
before vsock_core_init() has the chance to run.

[Wed Feb 27 14:17:09 2019] BUG: unable to handle kernel NULL pointer dereference at 0000000000000110
[Wed Feb 27 14:17:09 2019] #PF error: [normal kernel read fault]
[Wed Feb 27 14:17:09 2019] PGD 0 P4D 0
[Wed Feb 27 14:17:09 2019] Oops: 0000 [#1] SMP PTI
[Wed Feb 27 14:17:09 2019] CPU: 3 PID: 59 Comm: kworker/3:1 Not tainted 5.0.0-rc7-390-generic-hvi #390
[Wed Feb 27 14:17:09 2019] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[Wed Feb 27 14:17:09 2019] Workqueue: virtio_vsock virtio_transport_rx_work [vmw_vsock_virtio_transport]
[Wed Feb 27 14:17:09 2019] RIP: 0010:virtio_transport_reset_no_sock+0x8c/0xc0 [vmw_vsock_virtio_transport_common]
[Wed Feb 27 14:17:09 2019] Code: 35 8b 4f 14 48 8b 57 08 31 f6 44 8b 4f 10 44 8b 07 48 8d 7d c8 e8 84 f8 ff ff 48 85 c0 48 89 c3 74 2a e8 f7 31 03 00 48 89 df <48> 8b 80 10 01 00 00 e8 68 fb 69 ed 48 8b 75 f0 65 48 33 34 25 28
[Wed Feb 27 14:17:09 2019] RSP: 0018:ffffb42701ab7d40 EFLAGS: 00010282
[Wed Feb 27 14:17:09 2019] RAX: 0000000000000000 RBX: ffff9d79637ee080 RCX: 0000000000000003
[Wed Feb 27 14:17:09 2019] RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff9d79637ee080
[Wed Feb 27 14:17:09 2019] RBP: ffffb42701ab7d78 R08: ffff9d796fae70e0 R09: ffff9d796f403500
[Wed Feb 27 14:17:09 2019] R10: ffffb42701ab7d90 R11: 0000000000000000 R12: ffff9d7969d09240
[Wed Feb 27 14:17:09 2019] R13: ffff9d79624e6840 R14: ffff9d7969d09318 R15: ffff9d796d48ff80
[Wed Feb 27 14:17:09 2019] FS:  0000000000000000(0000) GS:ffff9d796fac0000(0000) knlGS:0000000000000000
[Wed Feb 27 14:17:09 2019] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[Wed Feb 27 14:17:09 2019] CR2: 0000000000000110 CR3: 0000000427f22000 CR4: 00000000000006e0
[Wed Feb 27 14:17:09 2019] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[Wed Feb 27 14:17:09 2019] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[Wed Feb 27 14:17:09 2019] Call Trace:
[Wed Feb 27 14:17:09 2019]  virtio_transport_recv_pkt+0x63/0x820 [vmw_vsock_virtio_transport_common]
[Wed Feb 27 14:17:09 2019]  ? kfree+0x17e/0x190
[Wed Feb 27 14:17:09 2019]  ? detach_buf_split+0x145/0x160
[Wed Feb 27 14:17:09 2019]  ? __switch_to_asm+0x40/0x70
[Wed Feb 27 14:17:09 2019]  virtio_transport_rx_work+0xa0/0x106 [vmw_vsock_virtio_transport]
[Wed Feb 27 14:17:09 2019] NET: Registered protocol family 40
[Wed Feb 27 14:17:09 2019]  process_one_work+0x167/0x410
[Wed Feb 27 14:17:09 2019]  worker_thread+0x4d/0x460
[Wed Feb 27 14:17:09 2019]  kthread+0x105/0x140
[Wed Feb 27 14:17:09 2019]  ? rescuer_thread+0x360/0x360
[Wed Feb 27 14:17:09 2019]  ? kthread_destroy_worker+0x50/0x50
[Wed Feb 27 14:17:09 2019]  ret_from_fork+0x35/0x40
[Wed Feb 27 14:17:09 2019] Modules linked in: vmw_vsock_virtio_transport vmw_vsock_virtio_transport_common input_leds vsock serio_raw i2c_piix4 mac_hid qemu_fw_cfg autofs4 cirrus ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops virtio_net psmouse drm net_failover pata_acpi virtio_blk failover floppy

Fixes: 22b5c0b6 ("vsock/virtio: fix kernel panic after device hot-unplug")
Reported-by: NAlexandru Herghelegiu <aherghelegiu@bitdefender.com>
Signed-off-by: NAdalbert Lazăr <alazar@bitdefender.com>
Co-developed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

proc_exit_connector() uses ->real_parent lockless. This is not
safe that its parent can go away at any moment, so use RCU to
protect it, and ensure that this task is not released.

[  747.624551] ==================================================================
[  747.632946] BUG: KASAN: use-after-free in proc_exit_connector+0x1f7/0x310
[  747.640686] Read of size 4 at addr ffff88a0276988e0 by task sshd/2882
[  747.648032]
[  747.649804] CPU: 11 PID: 2882 Comm: sshd Tainted: G            E     4.19.26-rc2 #11
[  747.658629] Hardware name: IBM x3550M4 -[7914OFV]-/00AM544, BIOS -[D7E142BUS-1.71]- 07/31/2014
[  747.668419] Call Trace:
[  747.671269]  dump_stack+0xf0/0x19b
[  747.675186]  ? show_regs_print_info+0x5/0x5
[  747.679988]  ? kmsg_dump_rewind_nolock+0x59/0x59
[  747.685302]  print_address_description+0x6a/0x270
[  747.691162]  kasan_report+0x258/0x380
[  747.695835]  ? proc_exit_connector+0x1f7/0x310
[  747.701402]  proc_exit_connector+0x1f7/0x310
[  747.706767]  ? proc_coredump_connector+0x2d0/0x2d0
[  747.712715]  ? _raw_write_unlock_irq+0x29/0x50
[  747.718270]  ? _raw_write_unlock_irq+0x29/0x50
[  747.723820]  ? ___preempt_schedule+0x16/0x18
[  747.729193]  ? ___preempt_schedule+0x16/0x18
[  747.734574]  do_exit+0xa11/0x14f0
[  747.738880]  ? mm_update_next_owner+0x590/0x590
[  747.744525]  ? debug_show_all_locks+0x3c0/0x3c0
[  747.761448]  ? ktime_get_coarse_real_ts64+0xeb/0x1c0
[  747.767589]  ? lockdep_hardirqs_on+0x1a6/0x290
[  747.773154]  ? check_chain_key+0x139/0x1f0
[  747.778345]  ? check_flags.part.35+0x240/0x240
[  747.783908]  ? __lock_acquire+0x2300/0x2300
[  747.789171]  ? _raw_spin_unlock_irqrestore+0x59/0x70
[  747.795316]  ? _raw_spin_unlock_irqrestore+0x59/0x70
[  747.801457]  ? do_raw_spin_unlock+0x10f/0x1e0
[  747.806914]  ? do_raw_spin_trylock+0x120/0x120
[  747.812481]  ? preempt_count_sub+0x14/0xc0
[  747.817645]  ? _raw_spin_unlock+0x2e/0x50
[  747.822708]  ? __handle_mm_fault+0x12db/0x1fa0
[  747.828367]  ? __pmd_alloc+0x2d0/0x2d0
[  747.833143]  ? check_noncircular+0x50/0x50
[  747.838309]  ? match_held_lock+0x7f/0x340
[  747.843380]  ? check_noncircular+0x50/0x50
[  747.848561]  ? handle_mm_fault+0x21a/0x5f0
[  747.853730]  ? check_flags.part.35+0x240/0x240
[  747.859290]  ? check_chain_key+0x139/0x1f0
[  747.864474]  ? __do_page_fault+0x40f/0x760
[  747.869655]  ? __audit_syscall_entry+0x4b/0x1f0
[  747.875319]  ? syscall_trace_enter+0x1d5/0x7b0
[  747.880877]  ? trace_raw_output_preemptirq_template+0x90/0x90
[  747.887895]  ? trace_raw_output_sys_exit+0x80/0x80
[  747.893860]  ? up_read+0x3b/0x90
[  747.898142]  ? stop_critical_timings+0x260/0x260
[  747.903909]  do_group_exit+0xe0/0x1c0
[  747.908591]  ? __x64_sys_exit+0x30/0x30
[  747.913460]  ? trace_raw_output_preemptirq_template+0x90/0x90
[  747.920485]  ? tracer_hardirqs_on+0x270/0x270
[  747.925956]  __x64_sys_exit_group+0x28/0x30
[  747.931214]  do_syscall_64+0x117/0x400
[  747.935988]  ? syscall_return_slowpath+0x2f0/0x2f0
[  747.941931]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[  747.947788]  ? trace_hardirqs_on_caller+0x1d0/0x1d0
[  747.953838]  ? lockdep_sys_exit+0x16/0x8e
[  747.958915]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[  747.964784]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  747.971021] RIP: 0033:0x7f572f154c68
[  747.975606] Code: Bad RIP value.
[  747.979791] RSP: 002b:00007ffed2dfaa58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
[  747.989324] RAX: ffffffffffffffda RBX: 00007f572f431840 RCX: 00007f572f154c68
[  747.997910] RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001
[  748.006495] RBP: 0000000000000001 R08: 00000000000000e7 R09: fffffffffffffee0
[  748.015079] R10: 00007f572f4387e8 R11: 0000000000000246 R12: 00007f572f431840
[  748.023664] R13: 000055a7f90f2c50 R14: 000055a7f96e2310 R15: 000055a7f96e2310
[  748.032287]
[  748.034509] Allocated by task 2300:
[  748.038982]  kasan_kmalloc+0xa0/0xd0
[  748.043562]  kmem_cache_alloc_node+0xf5/0x2e0
[  748.049018]  copy_process+0x1781/0x4790
[  748.053884]  _do_fork+0x166/0x9a0
[  748.058163]  do_syscall_64+0x117/0x400
[  748.062943]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  748.069180]
[  748.071405] Freed by task 15395:
[  748.075591]  __kasan_slab_free+0x130/0x180
[  748.080752]  kmem_cache_free+0xc2/0x310
[  748.085619]  free_task+0xea/0x130
[  748.089901]  __put_task_struct+0x177/0x230
[  748.095063]  finish_task_switch+0x51b/0x5d0
[  748.100315]  __schedule+0x506/0xfa0
[  748.104791]  schedule+0xca/0x260
[  748.108978]  futex_wait_queue_me+0x27e/0x420
[  748.114333]  futex_wait+0x251/0x550
[  748.118814]  do_futex+0x75b/0xf80
[  748.123097]  __x64_sys_futex+0x231/0x2a0
[  748.128065]  do_syscall_64+0x117/0x400
[  748.132835]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  748.139066]
[  748.141289] The buggy address belongs to the object at ffff88a027698000
[  748.141289]  which belongs to the cache task_struct of size 12160
[  748.156589] The buggy address is located 2272 bytes inside of
[  748.156589]  12160-byte region [ffff88a027698000, ffff88a02769af80)
[  748.171114] The buggy address belongs to the page:
[  748.177055] page:ffffea00809da600 count:1 mapcount:0 mapping:ffff888107d01e00 index:0x0 compound_mapcount: 0
[  748.189136] flags: 0x57ffffc0008100(slab|head)
[  748.194688] raw: 0057ffffc0008100 ffffea00809a3200 0000000300000003 ffff888107d01e00
[  748.204424] raw: 0000000000000000 0000000000020002 00000001ffffffff 0000000000000000
[  748.214146] page dumped because: kasan: bad access detected
[  748.220976]
[  748.223197] Memory state around the buggy address:
[  748.229128]  ffff88a027698780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  748.238271]  ffff88a027698800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  748.247414] >ffff88a027698880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  748.256564]                                                        ^
[  748.264267]  ffff88a027698900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  748.273493]  ffff88a027698980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  748.282630] ==================================================================

Fixes: b086ff87 ("connector: add parent pid and tgid to coredump and exit events")
Signed-off-by: NZhang Yu <zhangyu31@baidu.com>
Signed-off-by: NLi RongQing <lirongqing@baidu.com>
Acked-by: NEvgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

vxlan_cleanup() is a timer callback, it is already
and only running in BH context.
Signed-off-by: NLitao Jiao <jiaolitao@raisecom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

HW can not guarantee complete write desc->rx.size, even though
HNS3_RXD_VLD_B has been set. Driver needs to add dma_rmb()
instruction to make sure desc->rx.size is always valid.

Fixes: e5597095 ("net: hns3: Add handling of GRO Pkts not fully RX'ed in NAPI poll")
Signed-off-by: NJian Shen <shenjian15@huawei.com>
Signed-off-by: NHuazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds missing documentation for some inline functions on
linux/skbuff.h. The patch is incomplete and a lot more can be added,
just wondering if it's of interest of the netdev developers.

Also fixed some whitespaces.
Signed-off-by: NPedro Tammela <pctammela@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Christophe Roullier says:

====================
stmmac: add some fixes for stm32

For common stmmac:
	- Add support to set CSR Clock range selection in DT
For stm32mpu:
	- Glue codes to support magic packet
	- Glue codes to support all PHY config :
		PHY_MODE (MII,GMII, RMII, RGMII) and in normal,
		PHY wo crystal (25Mhz),
		PHY wo crystal (50Mhz), No 125Mhz from PHY config
For stm32mcu:
	- Add Ethernet support for stm32h7

Changes in V3:
	- Reverse for syscfg management because it is manage by these patches
	  https://lkml.org/lkml/2018/12/12/133
	  https://lkml.org/lkml/2018/12/12/134
	  https://lkml.org/lkml/2018/12/12/131
	  https://lkml.org/lkml/2018/12/12/132
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Synopsys GMAC 4.10 is used. And Phy mode for eval and disco is RMII
with PHY SMSC LAN8742
Signed-off-by: NChristophe Roullier <christophe.roullier@st.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Syscfg clock is no more needed.
Signed-off-by: NChristophe Roullier <christophe.roullier@st.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In Documentation stmmac.txt there is possibility to
fixed CSR Clock range selection with property clk_csr.
This patch add the management of this property
For example to use it, add in your ethernet node DT:
	clk_csr = <3>;
Signed-off-by: NChristophe Roullier <christophe.roullier@st.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add properties to support all Phy config
 PHY_MODE	(MII,GMII, RMII, RGMII) and in normal, PHY wo crystal (25Mhz),
 PHY wo crystal (50Mhz), No 125Mhz from PHY config.
Signed-off-by: NChristophe Roullier <christophe.roullier@st.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Update glue codes to support all PHY config on stm32mp157c
 PHY_MODE	(MII,GMII, RMII, RGMII) and in normal, PHY wo crystal (25Mhz),
PHY wo crystal (50Mhz), No 125Mhz from PHY config.
Signed-off-by: NChristophe Roullier <christophe.roullier@st.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add glue codes to support magic packet on stm32mp157c
Signed-off-by: NChristophe Roullier <christophe.roullier@st.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Xin Long says:

====================
sctp: process the error returned from sctp_sock_migrate()

This patchset is to process the errs returned by sctp_auth_init_hmacs()
and sctp_bind_addr_dup() from sctp_sock_migrate(). And also fix a panic
caused by new ep->auth_hmacs was not set due to net->sctp.auth_enable
changed by sysctl before accepting an assoc.
====================
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

New ep's auth_hmacs should be set if old ep's is set, in case that
net->sctp.auth_enable has been changed to 0 by users and new ep's
auth_hmacs couldn't be set in sctp_endpoint_init().

It can even crash kernel by doing:

  1. on server: sysctl -w net.sctp.auth_enable=1,
                sysctl -w net.sctp.addip_enable=1,
                sysctl -w net.sctp.addip_noauth_enable=0,
                listen() on server,
                sysctl -w net.sctp.auth_enable=0.
  2. on client: connect() to server.
  3. on server: accept() the asoc,
                sysctl -w net.sctp.auth_enable=1.
  4. on client: send() asconf packet to server.

The call trace:

  [  245.280251] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  [  245.286872] RIP: 0010:sctp_auth_calculate_hmac+0xa3/0x140 [sctp]
  [  245.304572] Call Trace:
  [  245.305091]  <IRQ>
  [  245.311287]  sctp_sf_authenticate+0x110/0x160 [sctp]
  [  245.312311]  sctp_sf_eat_auth+0xf2/0x230 [sctp]
  [  245.313249]  sctp_do_sm+0x9a/0x2d0 [sctp]
  [  245.321483]  sctp_assoc_bh_rcv+0xed/0x1a0 [sctp]
  [  245.322495]  sctp_rcv+0xa66/0xc70 [sctp]

It's because the old ep->auth_hmacs wasn't copied to the new ep while
ep->auth_hmacs is used in sctp_auth_calculate_hmac() when processing
the incoming auth chunks, and it should have been done when migrating
sock.
Reported-by: NYing Xu <yinxu@redhat.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NNeil Horman <nhorman@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sctp_auth_init_hmacs() is called only when ep->auth_enable is set.
It better to move up sctp_auth_init_hmacs() and remove auth_enable
check in it and check auth_enable only once in sctp_endpoint_init().
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It should fail to create the new sk if sctp_bind_addr_dup() fails
when accepting or peeloff an association.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If we receive a packet while deleting a VXLAN device, there's a chance
vxlan_rcv() is called at the same time as vxlan_dellink(). This is fine,
except that vxlan_dellink() should never ever touch stuff that's still in
use, such as the GRO cells list.

Otherwise, vxlan_rcv() crashes while queueing packets via
gro_cells_receive().

Move the gro_cells_destroy() to vxlan_uninit(), which runs after the RCU
grace period is elapsed and nothing needs the gro_cells anymore.

This is now done in the same way as commit 8e816df8 ("geneve: Use GRO
cells infrastructure.") originally implemented for GENEVE.
Reported-by: NJianlin Shi <jishi@redhat.com>
Fixes: 58ce31cc ("vxlan: GRO support at tunnel layer")
Signed-off-by: NStefano Brivio <sbrivio@redhat.com>
Reviewed-by: NSabrina Dubroca <sd@queasysnail.net>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

rxrpc_disconnect_client_call() reads the call's connection ID protocol
value (call->cid) as part of that function's variable declarations.  This
is bad because it's not inside the locked section and so may race with
someone granting use of the channel to the call.

This manifests as an assertion failure (see below) where the call in the
presumed channel (0 because call->cid wasn't set when we read it) doesn't
match the call attached to the channel we were actually granted (if 1, 2 or
3).

Fix this by moving the read and dependent calculations inside of the
channel_lock section.  Also, only set the channel number and pointer
variables if cid is not zero (ie. unset).

This problem can be induced by injecting an occasional error in
rxrpc_wait_for_channel() before the call to schedule().

Make two further changes also:

 (1) Add a trace for wait failure in rxrpc_connect_call().

 (2) Drop channel_lock before BUG'ing in the case of the assertion failure.

The failure causes a trace akin to the following:

rxrpc: Assertion failed - 18446612685268945920(0xffff8880beab8c00) == 18446612685268621312(0xffff8880bea69800) is false
------------[ cut here ]------------
kernel BUG at net/rxrpc/conn_client.c:824!
...
RIP: 0010:rxrpc_disconnect_client_call+0x2bf/0x99d
...
Call Trace:
 rxrpc_connect_call+0x902/0x9b3
 ? wake_up_q+0x54/0x54
 rxrpc_new_client_call+0x3a0/0x751
 ? rxrpc_kernel_begin_call+0x141/0x1bc
 ? afs_alloc_call+0x1b5/0x1b5
 rxrpc_kernel_begin_call+0x141/0x1bc
 afs_make_call+0x20c/0x525
 ? afs_alloc_call+0x1b5/0x1b5
 ? __lock_is_held+0x40/0x71
 ? lockdep_init_map+0xaf/0x193
 ? lockdep_init_map+0xaf/0x193
 ? __lock_is_held+0x40/0x71
 ? yfs_fs_fetch_data+0x33b/0x34a
 yfs_fs_fetch_data+0x33b/0x34a
 afs_fetch_data+0xdc/0x3b7
 afs_read_dir+0x52d/0x97f
 afs_dir_iterate+0xa0/0x661
 ? iterate_dir+0x63/0x141
 iterate_dir+0xa2/0x141
 ksys_getdents64+0x9f/0x11b
 ? filldir+0x111/0x111
 ? do_syscall_64+0x3e/0x1a0
 __x64_sys_getdents64+0x16/0x19
 do_syscall_64+0x7d/0x1a0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: 45025bce ("rxrpc: Improve management and caching of client connection objects")
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Reviewed-by: NMarc Dionne <marc.dionne@auristor.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

syzbot reported a NULL-ptr deref caused by that sched->init() in
sctp_stream_init() set stream->rr_next = NULL.

  kasan: GPF could be caused by NULL-ptr deref or user memory access
  RIP: 0010:sctp_sched_rr_dequeue+0xd3/0x170 net/sctp/stream_sched_rr.c:141
  Call Trace:
    sctp_outq_dequeue_data net/sctp/outqueue.c:90 [inline]
    sctp_outq_flush_data net/sctp/outqueue.c:1079 [inline]
    sctp_outq_flush+0xba2/0x2790 net/sctp/outqueue.c:1205

All sched info is saved in sout->ext now, in sctp_stream_init()
sctp_stream_alloc_out() will not change it, there's no need to
call sched->init() again, since sctp_outq_init() has already
done it.

Fixes: 5bbbbe32 ("sctp: introduce stream scheduler foundations")
Reported-by: syzbot+4c9934f20522c0efd657@syzkaller.appspotmail.com
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The race occurs in __mkroute_output() when 2 threads lookup a dst:

  CPU A                 CPU B
  find_exception()
                        find_exception() [fnhe expires]
                        ip_del_fnhe() [fnhe is deleted]
  rt_bind_exception()

In rt_bind_exception() it will bind a deleted fnhe with the new dst, and
this dst will get no chance to be freed. It causes a dev defcnt leak and
consecutive dmesg warnings:

  unregister_netdevice: waiting for ethX to become free. Usage count = 1

Especially thanks Jon to identify the issue.

This patch fixes it by setting fnhe_daddr to 0 in ip_del_fnhe() to stop
binding the deleted fnhe with a new dst when checking fnhe's fnhe_daddr
and daddr in rt_bind_exception().

It works as both ip_del_fnhe() and rt_bind_exception() are protected by
fnhe_lock and the fhne is freed by kfree_rcu().

Fixes: deed49df ("route: check and remove route cache when we get route")
Signed-off-by: NJon Maxwell <jmaxwell37@gmail.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Reviewed-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

syzbot found another add_timer() issue, this time in net/hsr [1]

Let's use mod_timer() which is safe.

[1]
kernel BUG at kernel/time/timer.c:1136!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 15909 Comm: syz-executor.3 Not tainted 5.0.0+ #97
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
kobject: 'loop2' (00000000f5629718): kobject_uevent_env
RIP: 0010:add_timer kernel/time/timer.c:1136 [inline]
RIP: 0010:add_timer+0x654/0xbe0 kernel/time/timer.c:1134
Code: 0f 94 c5 31 ff 44 89 ee e8 09 61 0f 00 45 84 ed 0f 84 77 fd ff ff e8 bb 5f 0f 00 e8 07 10 a0 ff e9 68 fd ff ff e8 ac 5f 0f 00 <0f> 0b e8 a5 5f 0f 00 0f 0b e8 9e 5f 0f 00 4c 89 b5 58 ff ff ff e9
RSP: 0018:ffff8880656eeca0 EFLAGS: 00010246
kobject: 'loop2' (00000000f5629718): fill_kobj_path: path = '/devices/virtual/block/loop2'
RAX: 0000000000040000 RBX: 1ffff1100caddd9a RCX: ffffc9000c436000
RDX: 0000000000040000 RSI: ffffffff816056c4 RDI: ffff88806a2f6cc8
RBP: ffff8880656eed58 R08: ffff888067f4a300 R09: ffff888067f4abc8
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88806a2f6cc0
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880656eed30
FS:  00007fc2019bf700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000738000 CR3: 0000000067e8e000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 hsr_check_announce net/hsr/hsr_device.c:99 [inline]
 hsr_check_carrier_and_operstate+0x567/0x6f0 net/hsr/hsr_device.c:120
 hsr_netdev_notify+0x297/0xa00 net/hsr/hsr_main.c:51
 notifier_call_chain+0xc7/0x240 kernel/notifier.c:93
 __raw_notifier_call_chain kernel/notifier.c:394 [inline]
 raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:401
 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1739
 call_netdevice_notifiers_extack net/core/dev.c:1751 [inline]
 call_netdevice_notifiers net/core/dev.c:1765 [inline]
 dev_open net/core/dev.c:1436 [inline]
 dev_open+0x143/0x160 net/core/dev.c:1424
 team_port_add drivers/net/team/team.c:1203 [inline]
 team_add_slave+0xa07/0x15d0 drivers/net/team/team.c:1933
 do_set_master net/core/rtnetlink.c:2358 [inline]
 do_set_master+0x1d4/0x230 net/core/rtnetlink.c:2332
 do_setlink+0x966/0x3510 net/core/rtnetlink.c:2493
 rtnl_setlink+0x271/0x3b0 net/core/rtnetlink.c:2747
 rtnetlink_rcv_msg+0x465/0xb00 net/core/rtnetlink.c:5192
 netlink_rcv_skb+0x17a/0x460 net/netlink/af_netlink.c:2485
 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5210
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0x536/0x720 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1925
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xdd/0x130 net/socket.c:632
 sock_write_iter+0x27c/0x3e0 net/socket.c:923
 call_write_iter include/linux/fs.h:1869 [inline]
 do_iter_readv_writev+0x5e0/0x8e0 fs/read_write.c:680
 do_iter_write fs/read_write.c:956 [inline]
 do_iter_write+0x184/0x610 fs/read_write.c:937
 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1001
 do_writev+0xf6/0x290 fs/read_write.c:1036
 __do_sys_writev fs/read_write.c:1109 [inline]
 __se_sys_writev fs/read_write.c:1106 [inline]
 __x64_sys_writev+0x75/0xb0 fs/read_write.c:1106
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457f29
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fc2019bec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457f29
RDX: 0000000000000001 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc2019bf6d4
R13: 00000000004c4a60 R14: 00000000004dd218 R15: 00000000ffffffff

Fixes: f421436a ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Cc: Arvid Brodin <arvid.brodin@alten.se>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The simple vNIC mailbox length should be 12 decimal and not 0x12.
Using a decimal also makes it clear this is a length value and not
another field within the simple mailbox defines.

Found by code inspection, there are no known firmware configurations
where this would cause issues.

Fixes: 527d7d1b ("nfp: read mailbox address from TLV caps")
Signed-off-by: NDirk van der Merwe <dirk.vandermerwe@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I removed compat's universal assignment to 0, which allows this if
statement to fall through when compat is passed with a value other
than 0.

Fixes: f9d19a74 ("net: atm: Use IS_ENABLED in atm_dev_ioctl")
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When building with -Wsometimes-uninitialized, Clang warns:

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:495:3: warning: variable 'ns' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:495:3: warning: variable 'ns' is used uninitialized whenever '&&' condition is false [-Wsometimes-uninitialized]
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:532:3: warning: variable 'ns' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:532:3: warning: variable 'ns' is used uninitialized whenever '&&' condition is false [-Wsometimes-uninitialized]
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:741:3: warning: variable 'sec_inc' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:741:3: warning: variable 'sec_inc' is used uninitialized whenever '&&' condition is false [-Wsometimes-uninitialized]

Clang is concerned with the use of stmmac_do_void_callback (which
stmmac_get_timestamp and stmmac_config_sub_second_increment wrap),
as it may fail to initialize these values if the if condition was ever
false (meaning the callbacks don't exist). It's not wrong because the
callbacks (get_timestamp and config_sub_second_increment respectively)
are the ones that initialize the variables. While it's unlikely that the
callbacks are ever going to disappear and make that condition false, we
can easily avoid this warning by zero initialize the variables.

Link: https://github.com/ClangBuiltLinux/linux/issues/384Suggested-by: NNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When building with -Wsometimes-uninitialized, Clang warns:

net/atm/resources.c:256:6: warning: variable 'number' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
net/atm/resources.c:212:7: warning: variable 'iobuf_len' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]

Clang won't realize that compat is 0 when CONFIG_COMPAT is not set until
the constant folding stage, which happens after this semantic analysis.
Use IS_ENABLED instead so that the zero is present at the semantic
analysis stage, which eliminates this warning.

Link: https://github.com/ClangBuiltLinux/linux/issues/386Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

clang inlines the dev_ethtool() more aggressively than gcc does, leading
to a larger amount of used stack space:

net/core/ethtool.c:2536:24: error: stack frame size of 1216 bytes in function 'dev_ethtool' [-Werror,-Wframe-larger-than=]

Marking the sub-functions that require the most stack space as
noinline_for_stack gives us reasonable behavior on all compilers.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NMichal Kubecek <mkubecek@suse.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Driver uses port-mtu as packet-size for the loopback traffic. This patch
limits the max packet size to 1.5K to avoid data being split over multiple
buffer descriptors (BDs) in cases where MTU > PAGE_SIZE.
Signed-off-by: NSudarsana Reddy Kalluru <skalluru@marvell.com>
Signed-off-by: NAriel Elior <aelior@marvell.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The enic driver relies on the CONFIG_CPUMASK_OFFSTACK feature to
dynamically allocate a struct member, but this is normally intended for
local variables.

Building with clang, I get a warning for a few locations that check the
address of the cpumask_var_t:

drivers/net/ethernet/cisco/enic/enic_main.c:122:22: error: address of array 'enic->msix[i].affinity_mask' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]

As far as I can tell, the code is still correct, as the truth value of
the pointer is what we need in this configuration. To get rid of
the warning, use cpumask_available() instead of checking the
pointer directly.

Fixes: 322cf7e3 ("enic: assign affinity hint to interrupts")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Clang points out undefined behavior when building the pcan_usb_pro driver:

drivers/net/can/usb/peak_usb/pcan_usb_pro.c:136:15: error: passing an object that undergoes default argument promotion to 'va_start' has undefined behavior [-Werror,-Wvarargs]

Changing the function prototype to avoid argument promotion in the
varargs call avoids the warning, and should make this well-defined.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Hardware has the CBS (Credit Based Shaper) which affects only Q3
and Q2. When updating the CBS settings, even if the driver does so
after waiting for Tx DMA finished, there is a possibility that frame
data still remains in TxFIFO.

To avoid this, decrease TxFIFO depth of Q3 and Q2 to one.

This patch has been exercised this using netperf TCP_MAERTS, TCP_STREAM
and UDP_STREAM tests run on an Ebisu board. No performance change was
detected, outside of noise in the tests, both in terms of throughput and
CPU utilisation.

Fixes: c156633f ("Renesas Ethernet AVB driver proper")
Signed-off-by: NMasaru Nagai <masaru.nagai.vx@renesas.com>
Signed-off-by: NKazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
[simon: updated changelog]
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

clang has spotted an ancient code bug and warns about it with:

drivers/isdn/isdnloop/isdnloop.c:573:12: error: address of array 'card->rcard' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]

This is an array of pointers, so we should check if a specific
pointer exists in the array before using it, not whether the
array itself exists.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

clang warns about what seems to be an unintended use of an obscure C
language feature where a forward declaration of an array remains usable
when the final definition is never seen:

drivers/net/ethernet/ti/davinci_emac.c:1694:34: error: tentative array definition assumed to have one element [-Werror]
static const struct of_device_id davinci_emac_of_match[];

There is no harm in always enabling the device tree matching code here,
and it makes the code behave in a more conventional way aside from
avoiding the warning.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Returning 0 as inq to userspace indicates there is no more data to
read, and the application needs to wait for EPOLLIN. For a connection
that has received FIN from the remote peer, however, the application
must continue reading until getting EOF (return value of 0
from tcp_recvmsg) or an error, if edge-triggered epoll (EPOLLET) is
being used. Otherwise, the application will never receive a new
EPOLLIN, since there is no epoll edge after the FIN.

Return 1 when there is no data left on the queue but the
connection has received FIN, so that the applications continue
reading.

Fixes: b75eba76 (tcp: send in-queue bytes in cmsg upon read)
Signed-off-by: NSoheil Hassas Yeganeh <soheil@google.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER) failed to
add port, it directly returns res and forgets to free the node
that allocated in hsr_create_self_node(), and forgets to delete
the node->mac_list linked in hsr->self_node_db.

BUG: memory leak
unreferenced object 0xffff8881cfa0c780 (size 64):
  comm "syz-executor.0", pid 2077, jiffies 4294717969 (age 2415.377s)
  hex dump (first 32 bytes):
    e0 c7 a0 cf 81 88 ff ff 00 02 00 00 00 00 ad de  ................
    00 e6 49 cd 81 88 ff ff c0 9b 87 d0 81 88 ff ff  ..I.............
  backtrace:
    [<00000000e2ff5070>] hsr_dev_finalize+0x736/0x960 [hsr]
    [<000000003ed2e597>] hsr_newlink+0x2b2/0x3e0 [hsr]
    [<000000003fa8c6b6>] __rtnl_newlink+0xf1f/0x1600 net/core/rtnetlink.c:3182
    [<000000001247a7ad>] rtnl_newlink+0x66/0x90 net/core/rtnetlink.c:3240
    [<00000000e7d1b61d>] rtnetlink_rcv_msg+0x54e/0xb90 net/core/rtnetlink.c:5130
    [<000000005556bd3a>] netlink_rcv_skb+0x129/0x340 net/netlink/af_netlink.c:2477
    [<00000000741d5ee6>] netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
    [<00000000741d5ee6>] netlink_unicast+0x49a/0x650 net/netlink/af_netlink.c:1336
    [<000000009d56f9b7>] netlink_sendmsg+0x88b/0xdf0 net/netlink/af_netlink.c:1917
    [<0000000046b35c59>] sock_sendmsg_nosec net/socket.c:621 [inline]
    [<0000000046b35c59>] sock_sendmsg+0xc3/0x100 net/socket.c:631
    [<00000000d208adc9>] __sys_sendto+0x33e/0x560 net/socket.c:1786
    [<00000000b582837a>] __do_sys_sendto net/socket.c:1798 [inline]
    [<00000000b582837a>] __se_sys_sendto net/socket.c:1794 [inline]
    [<00000000b582837a>] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:1794
    [<00000000c866801d>] do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
    [<00000000fea382d9>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
    [<00000000e01dacb3>] 0xffffffffffffffff

Fixes: c5a75911 ("net/hsr: Use list_head (and rcu) instead of array for slave devices.")
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NMao Wenan <maowenan@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When adding new filter to flower classifier, fl_change() inserts it to
handle_idr before initializing filter extensions and assigning it a mask.
Normally this ordering doesn't matter because all flower classifier ops
callbacks assume rtnl lock protection. However, when filter has an action
that doesn't have its kernel module loaded, rtnl lock is released before
call to request_module(). During this time the filter can be accessed bu
concurrent task before its initialization is completed, which can lead to a
crash.

Example case of NULL pointer dereference in concurrent dump:

Task 1                           Task 2

tc_new_tfilter()
 fl_change()
  idr_alloc_u32(fnew)
  fl_set_parms()
   tcf_exts_validate()
    tcf_action_init()
     tcf_action_init_1()
      rtnl_unlock()
      request_module()
      ...                        rtnl_lock()
      				 tc_dump_tfilter()
      				  tcf_chain_dump()
				   fl_walk()
				    idr_get_next_ul()
				    tcf_node_dump()
				     tcf_fill_node()
				      fl_dump()
				       mask = &f->mask->key; <- NULL ptr
      rtnl_lock()

Extension initialization and mask assignment don't depend on fnew->handle
that is allocated by idr_alloc_u32(). Move idr allocation code after action
creation and mask assignment in fl_change() to prevent concurrent access
to not fully initialized filter when rtnl lock is released to load action
module.

Fixes: 01683a14 ("net: sched: refactor flower walk to iterate over idr")
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Reviewed-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sendpage was not designed for processing of the Slab pages,
in some situations it can trigger BUG_ON on receiving side.
Signed-off-by: NVasily Averin <vvs@virtuozzo.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add the path names here so that git-send-email can pick up the
netdev@vger.kernel.org Cc line automatically for a patch that
only touches the headers.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A bugfix just broke compilation of appletalk when CONFIG_SYSCTL
is disabled:

In file included from net/appletalk/ddp.c:65:
net/appletalk/ddp.c: In function 'atalk_init':
include/linux/atalk.h:164:34: error: expected expression before 'do'
 #define atalk_register_sysctl()  do { } while(0)
                                  ^~
net/appletalk/ddp.c:1934:7: note: in expansion of macro 'atalk_register_sysctl'
  rc = atalk_register_sysctl();

This is easier to avoid by using conventional inline functions
as stubs rather than macros. The header already has inline
functions for other purposes, so I'm changing over all the
macros for consistency.

Fixes: 6377f787 ("appletalk: Fix use-after-free in atalk_proc_exit")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Naresh Kamboju noted the following oops during execution of selftest
tools/testing/selftests/bpf/test_tunnel.sh on x86_64:

[  274.120445] BUG: unable to handle kernel NULL pointer dereference
at 0000000000000000
[  274.128285] #PF error: [INSTR]
[  274.131351] PGD 8000000414a0e067 P4D 8000000414a0e067 PUD 3b6334067 PMD 0
[  274.138241] Oops: 0010 [#1] SMP PTI
[  274.141734] CPU: 1 PID: 11464 Comm: ping Not tainted
5.0.0-rc4-next-20190129 #1
[  274.149046] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS
2.0b 07/27/2017
[  274.156526] RIP: 0010:          (null)
[  274.160280] Code: Bad RIP value.
[  274.163509] RSP: 0018:ffffbc9681f83540 EFLAGS: 00010286
[  274.168726] RAX: 0000000000000000 RBX: ffffdc967fa80a18 RCX: 0000000000000000
[  274.175851] RDX: ffff9db2ee08b540 RSI: 000000000000000e RDI: ffffdc967fa809a0
[  274.182974] RBP: ffffbc9681f83580 R08: ffff9db2c4d62690 R09: 000000000000000c
[  274.190098] R10: 0000000000000000 R11: ffff9db2ee08b540 R12: ffff9db31ce7c000
[  274.197222] R13: 0000000000000001 R14: 000000000000000c R15: ffff9db3179cf400
[  274.204346] FS:  00007ff4ae7c5740(0000) GS:ffff9db31fa80000(0000)
knlGS:0000000000000000
[  274.212424] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  274.218162] CR2: ffffffffffffffd6 CR3: 00000004574da004 CR4: 00000000003606e0
[  274.225292] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  274.232416] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  274.239541] Call Trace:
[  274.241988]  ? tnl_update_pmtu+0x296/0x3b0
[  274.246085]  ip_md_tunnel_xmit+0x1bc/0x520
[  274.250176]  gre_fb_xmit+0x330/0x390
[  274.253754]  gre_tap_xmit+0x128/0x180
[  274.257414]  dev_hard_start_xmit+0xb7/0x300
[  274.261598]  sch_direct_xmit+0xf6/0x290
[  274.265430]  __qdisc_run+0x15d/0x5e0
[  274.269007]  __dev_queue_xmit+0x2c5/0xc00
[  274.273011]  ? dev_queue_xmit+0x10/0x20
[  274.276842]  ? eth_header+0x2b/0xc0
[  274.280326]  dev_queue_xmit+0x10/0x20
[  274.283984]  ? dev_queue_xmit+0x10/0x20
[  274.287813]  arp_xmit+0x1a/0xf0
[  274.290952]  arp_send_dst.part.19+0x46/0x60
[  274.295138]  arp_solicit+0x177/0x6b0
[  274.298708]  ? mod_timer+0x18e/0x440
[  274.302281]  neigh_probe+0x57/0x70
[  274.305684]  __neigh_event_send+0x197/0x2d0
[  274.309862]  neigh_resolve_output+0x18c/0x210
[  274.314212]  ip_finish_output2+0x257/0x690
[  274.318304]  ip_finish_output+0x219/0x340
[  274.322314]  ? ip_finish_output+0x219/0x340
[  274.326493]  ip_output+0x76/0x240
[  274.329805]  ? ip_fragment.constprop.53+0x80/0x80
[  274.334510]  ip_local_out+0x3f/0x70
[  274.337992]  ip_send_skb+0x19/0x40
[  274.341391]  ip_push_pending_frames+0x33/0x40
[  274.345740]  raw_sendmsg+0xc15/0x11d0
[  274.349403]  ? __might_fault+0x85/0x90
[  274.353151]  ? _copy_from_user+0x6b/0xa0
[  274.357070]  ? rw_copy_check_uvector+0x54/0x130
[  274.361604]  inet_sendmsg+0x42/0x1c0
[  274.365179]  ? inet_sendmsg+0x42/0x1c0
[  274.368937]  sock_sendmsg+0x3e/0x50
[  274.372460]  ___sys_sendmsg+0x26f/0x2d0
[  274.376293]  ? lock_acquire+0x95/0x190
[  274.380043]  ? __handle_mm_fault+0x7ce/0xb70
[  274.384307]  ? lock_acquire+0x95/0x190
[  274.388053]  ? __audit_syscall_entry+0xdd/0x130
[  274.392586]  ? ktime_get_coarse_real_ts64+0x64/0xc0
[  274.397461]  ? __audit_syscall_entry+0xdd/0x130
[  274.401989]  ? trace_hardirqs_on+0x4c/0x100
[  274.406173]  __sys_sendmsg+0x63/0xa0
[  274.409744]  ? __sys_sendmsg+0x63/0xa0
[  274.413488]  __x64_sys_sendmsg+0x1f/0x30
[  274.417405]  do_syscall_64+0x55/0x190
[  274.421064]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  274.426113] RIP: 0033:0x7ff4ae0e6e87
[  274.429686] Code: 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 80 00
00 00 00 8b 05 ca d9 2b 00 48 63 d2 48 63 ff 85 c0 75 10 b8 2e 00 00
00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 53 48 89 f3 48 83 ec 10 48 89 7c
24 08
[  274.448422] RSP: 002b:00007ffcd9b76db8 EFLAGS: 00000246 ORIG_RAX:
000000000000002e
[  274.455978] RAX: ffffffffffffffda RBX: 0000000000000040 RCX: 00007ff4ae0e6e87
[  274.463104] RDX: 0000000000000000 RSI: 00000000006092e0 RDI: 0000000000000003
[  274.470228] RBP: 0000000000000000 R08: 00007ffcd9bc40a0 R09: 00007ffcd9bc4080
[  274.477349] R10: 000000000000060a R11: 0000000000000246 R12: 0000000000000003
[  274.484475] R13: 0000000000000016 R14: 00007ffcd9b77fa0 R15: 00007ffcd9b78da4
[  274.491602] Modules linked in: cls_bpf sch_ingress iptable_filter
ip_tables algif_hash af_alg x86_pkg_temp_thermal fuse [last unloaded:
test_bpf]
[  274.504634] CR2: 0000000000000000
[  274.507976] ---[ end trace 196d18386545eae1 ]---
[  274.512588] RIP: 0010:          (null)
[  274.516334] Code: Bad RIP value.
[  274.519557] RSP: 0018:ffffbc9681f83540 EFLAGS: 00010286
[  274.524775] RAX: 0000000000000000 RBX: ffffdc967fa80a18 RCX: 0000000000000000
[  274.531921] RDX: ffff9db2ee08b540 RSI: 000000000000000e RDI: ffffdc967fa809a0
[  274.539082] RBP: ffffbc9681f83580 R08: ffff9db2c4d62690 R09: 000000000000000c
[  274.546205] R10: 0000000000000000 R11: ffff9db2ee08b540 R12: ffff9db31ce7c000
[  274.553329] R13: 0000000000000001 R14: 000000000000000c R15: ffff9db3179cf400
[  274.560456] FS:  00007ff4ae7c5740(0000) GS:ffff9db31fa80000(0000)
knlGS:0000000000000000
[  274.568541] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  274.574277] CR2: ffffffffffffffd6 CR3: 00000004574da004 CR4: 00000000003606e0
[  274.581403] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  274.588535] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  274.595658] Kernel panic - not syncing: Fatal exception in interrupt
[  274.602046] Kernel Offset: 0x14400000 from 0xffffffff81000000
(relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[  274.612827] ---[ end Kernel panic - not syncing: Fatal exception in
interrupt ]---
[  274.620387] ------------[ cut here ]------------

I'm also seeing the same failure on x86_64, and it reproduces
consistently.

>From poking around it looks like the skb's dst entry is being used
to calculate the mtu in:

mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;

...but because that dst_entry  has an "ops" value set to md_dst_ops,
the various ops (including mtu) are not set:

crash> struct sk_buff._skb_refdst ffff928f87447700 -x
      _skb_refdst = 0xffffcd6fbf5ea590
crash> struct dst_entry.ops 0xffffcd6fbf5ea590
  ops = 0xffffffffa0193800
crash> struct dst_ops.mtu 0xffffffffa0193800
  mtu = 0x0
crash>

I confirmed that the dst entry also has dst->input set to
dst_md_discard, so it looks like it's an entry that's been
initialized via __metadata_dst_init alright.

I think the fix here is to use skb_valid_dst(skb) - it checks
for  DST_METADATA also, and with that fix in place, the
problem - which was previously 100% reproducible - disappears.

The below patch resolves the panic and all bpf tunnel tests pass
without incident.

Fixes: c8b34e68 ("ip_tunnel: Add tnl_update_pmtu in ip_md_tunnel_xmit")
Reported-by: NNaresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: NAlan Maguire <alan.maguire@oracle.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Tested-by: NAnders Roxell <anders.roxell@linaro.org>
Reported-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Tested-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>