Commit Graph

482 Commits

Author SHA1 Message Date
Timur Celik 71828b2240 tun: fix blocking read
This patch moves setting of the current state into the loop. Otherwise
the task may end up in a busy wait loop if none of the break conditions
are met.

Signed-off-by: Timur Celik <mail@timurcelik.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-24 22:11:53 -08:00
George Amanakis 3a03cb8456 tun: move the call to tun_set_real_num_queues
Call tun_set_real_num_queues() after the increment of tun->numqueues
since the former depends on it. Otherwise, the number of queues is not
correctly accounted for, which results to warnings similar to:
"vnet0 selects TX queue 11, but real number of TX queues is 11".

Fixes: 0b7959b625 ("tun: publish tfile after it's fully initialized")
Reported-and-tested-by: George Amanakis <gamanakis@gmail.com>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-30 21:40:25 -08:00
Stanislav Fomichev 0b7959b625 tun: publish tfile after it's fully initialized
BUG: unable to handle kernel NULL pointer dereference at 00000000000000d1
Call Trace:
 ? napi_gro_frags+0xa7/0x2c0
 tun_get_user+0xb50/0xf20
 tun_chr_write_iter+0x53/0x70
 new_sync_write+0xff/0x160
 vfs_write+0x191/0x1e0
 __x64_sys_write+0x5e/0xd0
 do_syscall_64+0x47/0xf0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

I think there is a subtle race between sending a packet via tap and
attaching it:

CPU0:                    CPU1:
tun_chr_ioctl(TUNSETIFF)
  tun_set_iff
    tun_attach
      rcu_assign_pointer(tfile->tun, tun);
                         tun_fops->write_iter()
                           tun_chr_write_iter
                             tun_napi_alloc_frags
                               napi_get_frags
                                 napi->skb = napi_alloc_skb
      tun_napi_init
        netif_napi_add
          napi->skb = NULL
                              napi->skb is NULL here
                              napi_gro_frags
                                napi_frags_skb
				  skb = napi->skb
				  skb_reset_mac_header(skb)
				  panic()

Move rcu_assign_pointer(tfile->tun) and rcu_assign_pointer(tun->tfiles) to
be the last thing we do in tun_attach(); this should guarantee that when we
call tun_get() we always get an initialized object.

v2 changes:
* remove extra napi_mutex locks/unlocks for napi operations

Reported-by: syzbot <syzkaller@googlegroups.com>
Fixes: 90e33d4594 ("tun: enable napi_gro_frags() for TUN/TAP driver")

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-10 09:24:38 -05:00
Prashant Bhole 6342ca6447 tun: replace get_cpu_ptr with this_cpu_ptr when bh disabled
tun_xdp_one() runs with local bh disabled. So there is no need to
disable preemption by calling get_cpu_ptr while updating stats. This
patch replaces the use of get_cpu_ptr() with this_cpu_ptr() as a
micro-optimization. Also removes related put_cpu_ptr call.

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-14 13:36:26 -08:00
Petr Machata 3a37a9636c net: dev: Add extack argument to dev_set_mac_address()
A follow-up patch will add a notifier type NETDEV_PRE_CHANGEADDR, which
allows vetoing of MAC address changes. One prominent path to that
notification is through dev_set_mac_address(). Therefore give this
function an extack argument, so that it can be packed together with the
notification. Thus a textual reason for rejection (or a warning) can be
communicated back to the user.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-13 18:41:38 -08:00
David S. Miller 4cc1feeb6f Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Several conflicts, seemingly all over the place.

I used Stephen Rothwell's sample resolutions for many of these, if not
just to double check my own work, so definitely the credit largely
goes to him.

The NFP conflict consisted of a bug fix (moving operations
past the rhashtable operation) while chaning the initial
argument in the function call in the moved code.

The net/dsa/master.c conflict had to do with a bug fix intermixing of
making dsa_master_set_mtu() static with the fixing of the tagging
attribute location.

cls_flower had a conflict because the dup reject fix from Or
overlapped with the addition of port range classifiction.

__set_phy_supported()'s conflict was relatively easy to resolve
because Andrew fixed it in both trees, so it was just a matter
of taking the net-next copy.  Or at least I think it was :-)

Joe Stringer's fix to the handling of netns id 0 in bpf_sk_lookup()
intermixed with changes on how the sdif and caller_net are calculated
in these code paths in net-next.

The remaining BPF conflicts were largely about the addition of the
__bpf_md_ptr stuff in 'net' overlapping with adjustments and additions
to the relevant data structure where the MD pointer macros are used.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-09 21:43:31 -08:00
Li RongQing 5c327f673d tun: remove unnecessary check in tun_flow_update
caller has guaranted that rxhash is not zero

Signed-off-by: Li RongQing <lirongqing@baidu.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-06 12:15:53 -08:00
Li RongQing 83b1bc122c tun: align write-heavy flow entry members to a cache line
tun flow entry 'updated' fields are written when receive
every packet. Thus if a flow is receiving packets from a
particular flow entry, it'll cause false-sharing with
all the other who has looked it up, so move it in its own
cache line

and update 'queue_index' and 'update' field only when
they are changed to reduce the cache false-sharing.

Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Signed-off-by: Wang Li <wangli39@baidu.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-06 12:15:27 -08:00
Prashant Bhole 4e4b08e558 tun: remove skb access after netif_receive_skb
In tun.c skb->len was accessed while doing stats accounting after a
call to netif_receive_skb. We can not access skb after this call
because buffers may be dropped.

The fix for this bug would be to store skb->len in local variable and
then use it after netif_receive_skb(). IMO using xdp data size for
accounting bytes will be better because input for tun_xdp_one() is
xdp_buff.

Hence this patch:
- fixes a bug by removing skb access after netif_receive_skb()
- uses xdp data size for accounting bytes

[613.019057] BUG: KASAN: use-after-free in tun_sendmsg+0x77c/0xc50 [tun]
[613.021062] Read of size 4 at addr ffff8881da9ab7c0 by task vhost-1115/1155
[613.023073]
[613.024003] CPU: 0 PID: 1155 Comm: vhost-1115 Not tainted 4.20.0-rc3-vm+ #232
[613.026029] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[613.029116] Call Trace:
[613.031145]  dump_stack+0x5b/0x90
[613.032219]  print_address_description+0x6c/0x23c
[613.034156]  ? tun_sendmsg+0x77c/0xc50 [tun]
[613.036141]  kasan_report.cold.5+0x241/0x308
[613.038125]  tun_sendmsg+0x77c/0xc50 [tun]
[613.040109]  ? tun_get_user+0x1960/0x1960 [tun]
[613.042094]  ? __isolate_free_page+0x270/0x270
[613.045173]  vhost_tx_batch.isra.14+0xeb/0x1f0 [vhost_net]
[613.047127]  ? peek_head_len.part.13+0x90/0x90 [vhost_net]
[613.049096]  ? get_tx_bufs+0x5a/0x2c0 [vhost_net]
[613.051106]  ? vhost_enable_notify+0x2d8/0x420 [vhost]
[613.053139]  handle_tx_copy+0x2d0/0x8f0 [vhost_net]
[613.053139]  ? vhost_net_buf_peek+0x340/0x340 [vhost_net]
[613.053139]  ? __mutex_lock+0x8d9/0xb30
[613.053139]  ? finish_task_switch+0x8f/0x3f0
[613.053139]  ? handle_tx+0x32/0x120 [vhost_net]
[613.053139]  ? mutex_trylock+0x110/0x110
[613.053139]  ? finish_task_switch+0xcf/0x3f0
[613.053139]  ? finish_task_switch+0x240/0x3f0
[613.053139]  ? __switch_to_asm+0x34/0x70
[613.053139]  ? __switch_to_asm+0x40/0x70
[613.053139]  ? __schedule+0x506/0xf10
[613.053139]  handle_tx+0xc7/0x120 [vhost_net]
[613.053139]  vhost_worker+0x166/0x200 [vhost]
[613.053139]  ? vhost_dev_init+0x580/0x580 [vhost]
[613.053139]  ? __kthread_parkme+0x77/0x90
[613.053139]  ? vhost_dev_init+0x580/0x580 [vhost]
[613.053139]  kthread+0x1b1/0x1d0
[613.053139]  ? kthread_park+0xb0/0xb0
[613.053139]  ret_from_fork+0x35/0x40
[613.088705]
[613.088705] Allocated by task 1155:
[613.088705]  kasan_kmalloc+0xbf/0xe0
[613.088705]  kmem_cache_alloc+0xdc/0x220
[613.088705]  __build_skb+0x2a/0x160
[613.088705]  build_skb+0x14/0xc0
[613.088705]  tun_sendmsg+0x4f0/0xc50 [tun]
[613.088705]  vhost_tx_batch.isra.14+0xeb/0x1f0 [vhost_net]
[613.088705]  handle_tx_copy+0x2d0/0x8f0 [vhost_net]
[613.088705]  handle_tx+0xc7/0x120 [vhost_net]
[613.088705]  vhost_worker+0x166/0x200 [vhost]
[613.088705]  kthread+0x1b1/0x1d0
[613.088705]  ret_from_fork+0x35/0x40
[613.088705]
[613.088705] Freed by task 1155:
[613.088705]  __kasan_slab_free+0x12e/0x180
[613.088705]  kmem_cache_free+0xa0/0x230
[613.088705]  ip6_mc_input+0x40f/0x5a0
[613.088705]  ipv6_rcv+0xc9/0x1e0
[613.088705]  __netif_receive_skb_one_core+0xc1/0x100
[613.088705]  netif_receive_skb_internal+0xc4/0x270
[613.088705]  br_pass_frame_up+0x2b9/0x2e0
[613.088705]  br_handle_frame_finish+0x2fb/0x7a0
[613.088705]  br_handle_frame+0x30f/0x6c0
[613.088705]  __netif_receive_skb_core+0x61a/0x15b0
[613.088705]  __netif_receive_skb_one_core+0x8e/0x100
[613.088705]  netif_receive_skb_internal+0xc4/0x270
[613.088705]  tun_sendmsg+0x738/0xc50 [tun]
[613.088705]  vhost_tx_batch.isra.14+0xeb/0x1f0 [vhost_net]
[613.088705]  handle_tx_copy+0x2d0/0x8f0 [vhost_net]
[613.088705]  handle_tx+0xc7/0x120 [vhost_net]
[613.088705]  vhost_worker+0x166/0x200 [vhost]
[613.088705]  kthread+0x1b1/0x1d0
[613.088705]  ret_from_fork+0x35/0x40
[613.088705]
[613.088705] The buggy address belongs to the object at ffff8881da9ab740
[613.088705]  which belongs to the cache skbuff_head_cache of size 232

Fixes: 043d222f93 ("tuntap: accept an array of XDP buffs through sendmsg()")
Reviewed-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-03 14:10:27 -08:00
Nicolas Dichtel 35b827b6d0 tun: forbid iface creation with rtnl ops
It's not supported right now (the goal of the initial patch was to support
'ip link del' only).

Before the patch:
$ ip link add foo type tun
[  239.632660] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
[snip]
[  239.636410] RIP: 0010:register_netdevice+0x8e/0x3a0

This panic occurs because dev->netdev_ops is not set by tun_setup(). But to
have something usable, it will require more than just setting
netdev_ops.

Fixes: f019a7a594 ("tun: Implement ip link del tunXXX")
CC: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-30 17:31:03 -08:00
Nicolas Dichtel 26d31925cd tun: implement carrier change
The userspace may need to control the carrier state.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Didier Pallard <didier.pallard@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-30 17:16:38 -08:00
David S. Miller f2be6d710d Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-11-19 10:55:00 -08:00
Matthew Cover 8ebebcba55 tuntap: fix multiqueue rx
When writing packets to a descriptor associated with a combined queue, the
packets should end up on that queue.

Before this change all packets written to any descriptor associated with a
tap interface end up on rx-0, even when the descriptor is associated with a
different queue.

The rx traffic can be generated by either of the following.
  1. a simple tap program which spins up multiple queues and writes packets
     to each of the file descriptors
  2. tx from a qemu vm with a tap multiqueue netdev

The queue for rx traffic can be observed by either of the following (done
on the hypervisor in the qemu case).
  1. a simple netmap program which opens and reads from per-queue
     descriptors
  2. configuring RPS and doing per-cpu captures with rxtxcpu

Alternatively, if you printk() the return value of skb_get_rx_queue() just
before each instance of netif_receive_skb() in tun.c, you will get 65535
for every skb.

Calling skb_record_rx_queue() to set the rx queue to the queue_index fixes
the association between descriptor and rx queue.

Signed-off-by: Matthew Cover <matthew.cover@stackpath.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-18 19:05:43 -08:00
Eric Dumazet aa6daacaa1 tun: use netdev_alloc_frag() in tun_napi_alloc_frags()
In order to cook skbs in the same way than Ethernet drivers,
it is probably better to not use GFP_KERNEL, but rather
use the GFP_ATOMIC and PFMEMALLOC mechanisms provided by
netdev_alloc_frag().

This would allow to use tun driver even in memory stress
situations, especially if swap is used over this tun channel.

Fixes: 90e33d4594 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Petar Penkov <peterpenkov96@gmail.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-18 19:01:11 -08:00
David S. Miller 6f0271d929 tun: Adjust on-stack tun_page initialization.
Instead of constantly playing with the struct initializer
syntax trying to make gcc and CLang both happy, just clear
it out using memset().

>> drivers/net/tun.c:2503:42: warning: Using plain integer as NULL pointer

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-17 16:53:46 -08:00
Jason Wang f9e06c45cb tuntap: free XDP dropped packets in a batch
Thanks to the batched XDP buffs through msg_control. Instead of
calling put_page() for each page which involves a atomic operation,
let's batch them by record the last page that needs to be freed and
its refcnt count and free them in a batch.

Testpmd(virtio-user + vhost_net) + XDP_DROP shows 3.8% improvement.

Before: 4.71Mpps
After : 4.89Mpps

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-17 12:00:42 -08:00
Paolo Abeni f29eb2a96c tun: compute the RFS hash only if needed.
The tun XDP sendmsg code path, unconditionally computes the symmetric
hash of each packet for RFS's sake, even when we could skip it. e.g.
when the device has a single queue.

This change adds the check already in-place for the skb sendmsg path
to avoid unneeded hashing.

The above gives small, but measurable, performance gain for VM xmit
path when zerocopy is not enabled.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-07 22:22:16 -08:00
Serhey Popovych df52eab23d tun: Consistently configure generic netdev params via rtnetlink
Configuring generic network device parameters on tun will fail in
presence of IFLA_INFO_KIND attribute in IFLA_LINKINFO nested attribute
since tun_validate() always return failure.

This can be visualized with following ip-link(8) command sequences:

  # ip link set dev tun0 group 100
  # ip link set dev tun0 group 100 type tun
  RTNETLINK answers: Invalid argument

with contrast to dummy and veth drivers:

  # ip link set dev dummy0 group 100
  # ip link set dev dummy0 type dummy

  # ip link set dev veth0 group 100
  # ip link set dev veth0 group 100 type veth

Fix by returning zero in tun_validate() when @data is NULL that is
always in case since rtnl_link_ops->maxtype is zero in tun driver.

Fixes: f019a7a594 ("tun: Implement ip link del tunXXX")
Signed-off-by: Serhey Popovych <serhe.popovych@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-15 21:40:31 -07:00
Wang Li 4b035271fe net: tun: remove useless codes of tun_automq_select_queue
Because the function __skb_get_hash_symmetric always returns non-zero.

Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Signed-off-by: Wang Li <wangli39@baidu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-10 22:35:22 -07:00
David S. Miller 6f41617bf2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Minor conflict in net/core/rtnetlink.c, David Ahern's bug fix in 'net'
overlapped the renaming of a netlink attribute in net-next.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-03 21:00:17 -07:00
Eric Dumazet af3fb24eec tun: napi flags belong to tfile
Since tun->flags might be shared by multiple tfile structures,
it is better to make sure tun_get_user() is using the flags
for the current tfile.

Presence of the READ_ONCE() in tun_napi_frags_enabled() gave a hint
of what could happen, but we need something stronger to please
syzbot.

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 13647 Comm: syz-executor5 Not tainted 4.19.0-rc5+ #59
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427
Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4
RSP: 0018:ffff8801c400f410 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325
RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0
RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000
R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358
R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004
FS:  00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 napi_gro_frags+0x3f4/0xc90 net/core/dev.c:5715
 tun_get_user+0x31d5/0x42a0 drivers/net/tun.c:1922
 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:1967
 call_write_iter include/linux/fs.h:1808 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x6b8/0x9f0 fs/read_write.c:487
 vfs_write+0x1fc/0x560 fs/read_write.c:549
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457579
Code: 1d b4 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 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fe003614c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579
RDX: 0000000000000012 RSI: 0000000020000000 RDI: 000000000000000a
RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0036156d4
R13: 00000000004c5574 R14: 00000000004d8e98 R15: 00000000ffffffff
Modules linked in:

RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427
Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4
RSP: 0018:ffff8801c400f410 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325
RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0
RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000
R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358
R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004
FS:  00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Fixes: 90e33d4594 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-01 23:27:28 -07:00
Eric Dumazet c7256f579f tun: initialize napi_mutex unconditionally
This is the first part to fix following syzbot report :

console output: https://syzkaller.appspot.com/x/log.txt?x=145378e6400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=443816db871edd66
dashboard link: https://syzkaller.appspot.com/bug?extid=e662df0ac1d753b57e80

Following patch is fixing the race condition, but it seems safer
to initialize this mutex at tfile creation anyway.

Fixes: 90e33d4594 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot+e662df0ac1d753b57e80@syzkaller.appspotmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-01 23:27:28 -07:00
Eric Dumazet 06e55addd3 tun: remove unused parameters
tun_napi_disable() and tun_napi_del() do not need
a pointer to the tun_struct

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-01 23:27:28 -07:00
David S. Miller a06ee256e5 Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net
Version bump conflict in batman-adv, take what's in net-next.

iavf conflict, adjustment of netdev_ops in net-next conflicting
with poll controller method removal in net.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-25 10:35:29 -07:00
Eric Dumazet 765cdc209c tun: remove ndo_poll_controller
As diagnosed by Song Liu, ndo_poll_controller() can
be very dangerous on loaded hosts, since the cpu
calling ndo_poll_controller() might steal all NAPI
contexts (for all RX/TX queues of the NIC). This capture
can last for unlimited amount of time, since one
cpu is generally not able to drain all the queues under load.

tun uses NAPI for TX completions, so we better let core
networking stack call the napi->poll() to avoid the capture.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-23 21:55:25 -07:00
Jason Wang 043d222f93 tuntap: accept an array of XDP buffs through sendmsg()
This patch implement TUN_MSG_PTR msg_control type. This type allows
the caller to pass an array of XDP buffs to tuntap through ptr field
of the tun_msg_control. If an XDP program is attached, tuntap can run
XDP program directly. If not, tuntap will build skb and do a fast
receiving since part of the work has been done by vhost_net.

This will avoid lots of indirect calls thus improves the icache
utilization and allows to do XDP batched flushing when doing XDP
redirection.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-13 09:25:40 -07:00
Jason Wang fe8dd45bb7 tun: switch to new type of msg_control
This patch introduces to a new tun/tap specific msg_control:

#define TUN_MSG_UBUF 1
#define TUN_MSG_PTR  2
struct tun_msg_ctl {
       int type;
       void *ptr;
};

This allows us to pass different kinds of msg_control through
sendmsg(). The first supported type is ubuf (TUN_MSG_UBUF) which will
be used by the existed vhost_net zerocopy code. The second is XDP
buff, which allows vhost_net to pass XDP buff to TUN. This could be
used to implement accepting an array of XDP buffs from vhost_net in
the following patches.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-13 09:25:40 -07:00
Jason Wang 1a097910ad tuntap: move XDP flushing out of tun_do_xdp()
This will allow adding batch flushing on top.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-13 09:25:40 -07:00
Jason Wang 8ae1aff0b3 tuntap: split out XDP logic
This patch split out XDP logic into a single function. This make it to
be reused by XDP batching path in the following patch.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-13 09:25:40 -07:00
Jason Wang ac1f1f6c5a tuntap: tweak on the path of skb XDP case in tun_build_skb()
If we're sure not to go native XDP, there's no need for several things
like bh and rcu stuffs. So this patch introduces a helper to build skb
and hold page refcnt. When we found we will go through skb path, build
skb directly.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-13 09:25:40 -07:00
Jason Wang f7053b6ccb tuntap: simplify error handling in tun_build_skb()
There's no need to duplicate page get logic in each action. So this
patch tries to get page and calculate the offset before processing XDP
actions (except for XDP_DROP), and undo them when meet errors (we
don't care the performance on errors). This will be used for factoring
out XDP logic.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-13 09:25:40 -07:00
Jason Wang 291aeb2b1d tuntap: enable bh early during processing XDP
This patch move the bh enabling a little bit earlier, this will be
used for factoring out the core XDP logic of tuntap.

Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-13 09:25:40 -07:00
Jason Wang 4f23aff871 tuntap: switch to use XDP_PACKET_HEADROOM
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-13 09:25:40 -07:00
Jason Wang e4a2a3048e net: sock: introduce SOCK_XDP
This patch introduces a new sock flag - SOCK_XDP. This will be used
for notifying the upper layer that XDP program is attached on the
lower socket, and requires for extra headroom.

TUN will be the first user.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-13 09:25:40 -07:00
Linus Torvalds 0214f46b3a Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull core signal handling updates from Eric Biederman:
 "It was observed that a periodic timer in combination with a
  sufficiently expensive fork could prevent fork from every completing.
  This contains the changes to remove the need for that restart.

  This set of changes is split into several parts:

   - The first part makes PIDTYPE_TGID a proper pid type instead
     something only for very special cases. The part starts using
     PIDTYPE_TGID enough so that in __send_signal where signals are
     actually delivered we know if the signal is being sent to a a group
     of processes or just a single process.

   - With that prep work out of the way the logic in fork is modified so
     that fork logically makes signals received while it is running
     appear to be received after the fork completes"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (22 commits)
  signal: Don't send signals to tasks that don't exist
  signal: Don't restart fork when signals come in.
  fork: Have new threads join on-going signal group stops
  fork: Skip setting TIF_SIGPENDING in ptrace_init_task
  signal: Add calculate_sigpending()
  fork: Unconditionally exit if a fatal signal is pending
  fork: Move and describe why the code examines PIDNS_ADDING
  signal: Push pid type down into complete_signal.
  signal: Push pid type down into __send_signal
  signal: Push pid type down into send_signal
  signal: Pass pid type into do_send_sig_info
  signal: Pass pid type into send_sigio_to_task & send_sigurg_to_task
  signal: Pass pid type into group_send_sig_info
  signal: Pass pid and pid type into send_sigqueue
  posix-timers: Noralize good_sigevent
  signal: Use PIDTYPE_TGID to clearly store where file signals will be sent
  pid: Implement PIDTYPE_TGID
  pids: Move the pgrp and session pid pointers from task_struct to signal_struct
  kvm: Don't open code task_pid in kvm_vcpu_ioctl
  pids: Compute task_tgid using signal->leader_pid
  ...
2018-08-21 13:47:29 -07:00
Li RongQing f13b546847 tun: not use hardcoded mask value
0x3ff in tun_hashfn is mask of TUN_NUM_FLOW_ENTRIES, instead
of hardcode, define a macro to setup the relationship with
TUN_NUM_FLOW_ENTRIES

Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-04 13:15:11 -07:00
Eric W. Biederman 019191342f signal: Use PIDTYPE_TGID to clearly store where file signals will be sent
When f_setown is called a pid and a pid type are stored.  Replace the use
of PIDTYPE_PID with PIDTYPE_TGID as PIDTYPE_TGID goes to the entire thread
group.  Replace the use of PIDTYPE_MAX with PIDTYPE_PID as PIDTYPE_PID now
is only for a thread.

Update the users of __f_setown to use PIDTYPE_TGID instead of
PIDTYPE_PID.

For now the code continues to capture task_pid (when task_tgid would
really be appropriate), and iterate on PIDTYPE_PID (even when type ==
PIDTYPE_TGID) out of an abundance of caution to preserve existing
behavior.

Oleg Nesterov suggested using the test to ensure we use PIDTYPE_PID
for tgid lookup also be used to avoid taking the tasklist lock.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 10:43:12 -05:00
David S. Miller c4c5551df1 Merge ra.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux
All conflicts were trivial overlapping changes, so reasonably
easy to resolve.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-20 21:17:12 -07:00
Toshiaki Makita 6e8cfd6d9d tun: Fix use-after-free on XDP_TX
On XDP_TX we need to free up the frame only when tun_xdp_tx() returns a
negative value. A positive value indicates that the packet is
successfully enqueued to the ptr_ring, so freeing the page causes
use-after-free.

Fixes: 735fc4054b ("xdp: change ndo_xdp_xmit API to support bulking")
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-16 13:38:29 -07:00
David S. Miller 2aa4a3378a Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-07-15

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Various different arm32 JIT improvements in order to optimize code emission
   and make the JIT code itself more robust, from Russell.

2) Support simultaneous driver and offloaded XDP in order to allow for advanced
   use-cases where some work is offloaded to the NIC and some to the host. Also
   add ability for bpftool to load programs and maps beyond just the cgroup case,
   from Jakub.

3) Add BPF JIT support in nfp for multiplication as well as division. For the
   latter in particular, it uses the reciprocal algorithm to emulate it, from Jiong.

4) Add BTF pretty print functionality to bpftool in plain and JSON output
   format, from Okash.

5) Add build and installation to the BPF helper man page into bpftool, from Quentin.

6) Add a TCP BPF callback for listening sockets which is triggered right after
   the socket transitions to TCP_LISTEN state, from Andrey.

7) Add a new cgroup tree command to bpftool which iterates over the whole cgroup
   tree and prints all attached programs, from Roman.

8) Improve xdp_redirect_cpu sample to support parsing of double VLAN tagged
   packets, from Jesper.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-14 18:47:44 -07:00
Jakub Kicinski 6b86758973 xdp: don't make drivers report attachment mode
prog_attached of struct netdev_bpf should have been superseded
by simply setting prog_id long time ago, but we kept it around
to allow offloading drivers to communicate attachment mode (drv
vs hw).  Subsequently drivers were also allowed to report back
attachment flags (prog_flags), and since nowadays only programs
attached will XDP_FLAGS_HW_MODE can get offloaded, we can tell
the attachment mode from the flags driver reports.  Remove
prog_attached member.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-13 20:26:35 +02:00
Alexander Duyck 4f49dec907 net: allow ndo_select_queue to pass netdev
This patch makes it so that instead of passing a void pointer as the
accel_priv we instead pass a net_device pointer as sb_dev. Making this
change allows us to pass the subordinate device through to the fallback
function eventually so that we can keep the actual code in the
ndo_select_queue call as focused on possible on the exception cases.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2018-07-09 13:41:34 -07:00
Willem de Bruijn fd3a886258 net: in virtio_net_hdr only add VLAN_HLEN to csum_start if payload holds vlan
Tun, tap, virtio, packet and uml vector all use struct virtio_net_hdr
to communicate packet metadata to userspace.

For skbuffs with vlan, the first two return the packet as it may have
existed on the wire, inserting the VLAN tag in the user buffer.  Then
virtio_net_hdr.csum_start needs to be adjusted by VLAN_HLEN bytes.

Commit f09e2249c4 ("macvtap: restore vlan header on user read")
added this feature to macvtap. Commit 3ce9b20f19 ("macvtap: Fix
csum_start when VLAN tags are present") then fixed up csum_start.

Virtio, packet and uml do not insert the vlan header in the user
buffer.

When introducing virtio_net_hdr_from_skb to deduplicate filling in
the virtio_net_hdr, the variant from macvtap which adds VLAN_HLEN was
applied uniformly, breaking csum offset for packets with vlan on
virtio and packet.

Make insertion of VLAN_HLEN optional. Convert the callers to pass it
when needed.

Fixes: e858fae2b0 ("virtio_net: use common code for virtio_net_hdr and skb GSO conversion")
Fixes: 1276f24eee ("packet: use common code for virtio_net_hdr and skb GSO conversion")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-07 16:15:38 -04:00
David S. Miller fd129f8941 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-06-05

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Add a new BPF hook for sendmsg similar to existing hooks for bind and
   connect: "This allows to override source IP (including the case when it's
   set via cmsg(3)) and destination IP:port for unconnected UDP (slow path).
   TCP and connected UDP (fast path) are not affected. This makes UDP support
   complete, that is, connected UDP is handled by connect hooks, unconnected
   by sendmsg ones.", from Andrey.

2) Rework of the AF_XDP API to allow extending it in future for type writer
   model if necessary. In this mode a memory window is passed to hardware
   and multiple frames might be filled into that window instead of just one
   that is the case in the current fixed frame-size model. With the new
   changes made this can be supported without having to add a new descriptor
   format. Also, core bits for the zero-copy support for AF_XDP have been
   merged as agreed upon, where i40e bits will be routed via Jeff later on.
   Various improvements to documentation and sample programs included as
   well, all from Björn and Magnus.

3) Given BPF's flexibility, a new program type has been added to implement
   infrared decoders. Quote: "The kernel IR decoders support the most
   widely used IR protocols, but there are many protocols which are not
   supported. [...] There is a 'long tail' of unsupported IR protocols,
   for which lircd is need to decode the IR. IR encoding is done in such
   a way that some simple circuit can decode it; therefore, BPF is ideal.
   [...] user-space can define a decoder in BPF, attach it to the rc
   device through the lirc chardev.", from Sean.

4) Several improvements and fixes to BPF core, among others, dumping map
   and prog IDs into fdinfo which is a straight forward way to correlate
   BPF objects used by applications, removing an indirect call and therefore
   retpoline in all map lookup/update/delete calls by invoking the callback
   directly for 64 bit archs, adding a new bpf_skb_cgroup_id() BPF helper
   for tc BPF programs to have an efficient way of looking up cgroup v2 id
   for policy or other use cases. Fixes to make sure we zero tunnel/xfrm
   state that hasn't been filled, to allow context access wrt pt_regs in
   32 bit archs for tracing, and last but not least various test cases
   for fixes that landed in bpf earlier, from Daniel.

5) Get rid of the ndo_xdp_flush API and extend the ndo_xdp_xmit with
   a XDP_XMIT_FLUSH flag instead which allows to avoid one indirect
   call as flushing is now merged directly into ndo_xdp_xmit(), from Jesper.

6) Add a new bpf_get_current_cgroup_id() helper that can be used in
   tracing to retrieve the cgroup id from the current process in order
   to allow for e.g. aggregation of container-level events, from Yonghong.

7) Two follow-up fixes for BTF to reject invalid input values and
   related to that also two test cases for BPF kselftests, from Martin.

8) Various API improvements to the bpf_fib_lookup() helper, that is,
   dropping MPLS bits which are not fully hashed out yet, rejecting
   invalid helper flags, returning error for unsupported address
   families as well as renaming flowlabel to flowinfo, from David.

9) Various fixes and improvements to sockmap BPF kselftests in particular
   in proper error detection and data verification, from Prashant.

10) Two arm32 BPF JIT improvements. One is to fix imm range check with
    regards to whether immediate fits into 24 bits, and a naming cleanup
    to get functions related to rsh handling consistent to those handling
    lsh, from Wang.

11) Two compile warning fixes in BPF, one for BTF and a false positive
    to silent gcc in stack_map_get_build_id_offset(), from Arnd.

12) Add missing seg6.h header into tools include infrastructure in order
    to fix compilation of BPF kselftests, from Mathieu.

13) Several formatting cleanups in the BPF UAPI helper description that
    also fix an error during rst2man compilation, from Quentin.

14) Hide an unused variable in sk_msg_convert_ctx_access() when IPv6 is
    not built into the kernel, from Yue.

15) Remove a useless double assignment in dev_map_enqueue(), from Colin.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-05 12:42:19 -04:00
Jesper Dangaard Brouer 42421a5654 tun: remove ndo_xdp_flush call tun_xdp_flush
Remove the ndo_xdp_flush call implementation tun_xdp_flush
as no callers of ndo_xdp_flush are left.

The tun drivers XDP_TX implementation also used tun_xdp_flush (and
tun_xdp_xmit).  This is easily solved by passing the XDP_XMIT_FLUSH
flag to tun_xdp_xmit in tun_xdp_tx.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-06-05 14:03:16 +02:00
Chas Williams 4e24f2dd51 Allow ethtool to change tun link settings
Let user space set whatever it would like to advertise for the
tun interface.  Preserve the existing defaults.

Signed-off-by: Chas Williams <3chas3@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-04 16:05:16 -04:00
Jesper Dangaard Brouer 0c9d917b7d tun: implement flush flag for ndo_xdp_xmit
When passed the XDP_XMIT_FLUSH flag tun_xdp_xmit now performs the same
kind of socket wake up as in tun_xdp_flush(). The wake up code from
tun_xdp_flush is generalized and shared with tun_xdp_xmit.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-06-03 08:11:34 -07:00
Jesper Dangaard Brouer 42b3346898 xdp: add flags argument to ndo_xdp_xmit API
This patch only change the API and reject any use of flags. This is an
intermediate step that allows us to implement the flush flag operation
later, for each individual driver in a separate patch.

The plan is to implement flush operation via XDP_XMIT_FLUSH flag
and then remove XDP_XMIT_FLAGS_NONE when done.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-06-03 08:11:34 -07:00
David S. Miller 9c54aeb03a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Filling in the padding slot in the bpf structure as a bug fix in 'ne'
overlapped with actually using that padding area for something in
'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-03 09:31:58 -04:00
Toshiaki Makita 6547e387d7 tun: Fix NULL pointer dereference in XDP redirect
Calling XDP redirection requires bh disabled. Softirq can call another
XDP function and redirection functions, then the percpu static variable
ri->map can be overwritten to NULL.

This is a generic XDP case called from tun.

[ 3535.736058] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
[ 3535.743974] PGD 0 P4D 0
[ 3535.746530] Oops: 0000 [#1] SMP PTI
[ 3535.750049] Modules linked in: vhost_net vhost tap tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc vfat fat ext4 mbcache jbd2 intel_rapl skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm ipmi_ssif irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc ses aesni_intel crypto_simd cryptd enclosure hpwdt hpilo glue_helper ipmi_si pcspkr wmi mei_me ioatdma mei ipmi_devintf shpchp dca ipmi_msghandler lpc_ich acpi_power_meter sch_fq_codel ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm smartpqi i40e crc32c_intel scsi_transport_sas tg3 i2c_core ptp pps_core
[ 3535.813456] CPU: 5 PID: 1630 Comm: vhost-1614 Not tainted 4.17.0-rc4 #2
[ 3535.820127] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 11/14/2017
[ 3535.828732] RIP: 0010:__xdp_map_lookup_elem+0x5/0x30
[ 3535.833740] RSP: 0018:ffffb4bc47bf7c58 EFLAGS: 00010246
[ 3535.839009] RAX: ffff9fdfcfea1c40 RBX: 0000000000000000 RCX: ffff9fdf27fe3100
[ 3535.846205] RDX: ffff9fdfca769200 RSI: 0000000000000000 RDI: 0000000000000000
[ 3535.853402] RBP: ffffb4bc491d9000 R08: 00000000000045ad R09: 0000000000000ec0
[ 3535.860597] R10: 0000000000000001 R11: ffff9fdf26c3ce4e R12: ffff9fdf9e72c000
[ 3535.867794] R13: 0000000000000000 R14: fffffffffffffff2 R15: ffff9fdfc82cdd00
[ 3535.874990] FS:  0000000000000000(0000) GS:ffff9fdfcfe80000(0000) knlGS:0000000000000000
[ 3535.883152] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 3535.888948] CR2: 0000000000000018 CR3: 0000000bde724004 CR4: 00000000007626e0
[ 3535.896145] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 3535.903342] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 3535.910538] PKRU: 55555554
[ 3535.913267] Call Trace:
[ 3535.915736]  xdp_do_generic_redirect+0x7a/0x310
[ 3535.920310]  do_xdp_generic.part.117+0x285/0x370
[ 3535.924970]  tun_get_user+0x5b9/0x1260 [tun]
[ 3535.929279]  tun_sendmsg+0x52/0x70 [tun]
[ 3535.933237]  handle_tx+0x2ad/0x5f0 [vhost_net]
[ 3535.937721]  vhost_worker+0xa5/0x100 [vhost]
[ 3535.942030]  kthread+0xf5/0x130
[ 3535.945198]  ? vhost_dev_ioctl+0x3b0/0x3b0 [vhost]
[ 3535.950031]  ? kthread_bind+0x10/0x10
[ 3535.953727]  ret_from_fork+0x35/0x40
[ 3535.957334] Code: 0e 74 15 83 f8 10 75 05 e9 49 aa b3 ff f3 c3 0f 1f 80 00 00 00 00 f3 c3 e9 29 9d b3 ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <8b> 47 18 83 f8 0e 74 0d 83 f8 10 75 05 e9 49 a9 b3 ff 31 c0 c3
[ 3535.976387] RIP: __xdp_map_lookup_elem+0x5/0x30 RSP: ffffb4bc47bf7c58
[ 3535.982883] CR2: 0000000000000018
[ 3535.987096] ---[ end trace 383b299dd1430240 ]---
[ 3536.131325] Kernel panic - not syncing: Fatal exception
[ 3536.137484] Kernel Offset: 0x26a00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[ 3536.281406] ---[ end Kernel panic - not syncing: Fatal exception ]---

And a kernel with generic case fixed still panics in tun driver XDP
redirect, because it disabled only preemption, but not bh.

[ 2055.128746] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
[ 2055.136662] PGD 0 P4D 0
[ 2055.139219] Oops: 0000 [#1] SMP PTI
[ 2055.142736] Modules linked in: vhost_net vhost tap tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc vfat fat ext4 mbcache jbd2 intel_rapl skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc ses aesni_intel ipmi_ssif crypto_simd enclosure cryptd hpwdt glue_helper ioatdma hpilo wmi dca pcspkr ipmi_si acpi_power_meter ipmi_devintf shpchp mei_me ipmi_msghandler mei lpc_ich sch_fq_codel ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm i40e smartpqi tg3 scsi_transport_sas crc32c_intel i2c_core ptp pps_core
[ 2055.206142] CPU: 6 PID: 1693 Comm: vhost-1683 Tainted: G        W         4.17.0-rc5-fix-tun+ #1
[ 2055.215011] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 11/14/2017
[ 2055.223617] RIP: 0010:__xdp_map_lookup_elem+0x5/0x30
[ 2055.228624] RSP: 0018:ffff998b07607cc0 EFLAGS: 00010246
[ 2055.233892] RAX: ffff8dbd8e235700 RBX: ffff8dbd8ff21c40 RCX: 0000000000000004
[ 2055.241089] RDX: ffff998b097a9000 RSI: 0000000000000000 RDI: 0000000000000000
[ 2055.248286] RBP: 0000000000000000 R08: 00000000000065a8 R09: 0000000000005d80
[ 2055.255483] R10: 0000000000000040 R11: ffff8dbcf0100000 R12: ffff998b097a9000
[ 2055.262681] R13: ffff8dbd8c98c000 R14: 0000000000000000 R15: ffff998b07607d78
[ 2055.269879] FS:  0000000000000000(0000) GS:ffff8dbd8ff00000(0000) knlGS:0000000000000000
[ 2055.278039] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2055.283834] CR2: 0000000000000018 CR3: 0000000c0c8cc005 CR4: 00000000007626e0
[ 2055.291030] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 2055.298227] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 2055.305424] PKRU: 55555554
[ 2055.308153] Call Trace:
[ 2055.310624]  xdp_do_redirect+0x7b/0x380
[ 2055.314499]  tun_get_user+0x10fe/0x12a0 [tun]
[ 2055.318895]  tun_sendmsg+0x52/0x70 [tun]
[ 2055.322852]  handle_tx+0x2ad/0x5f0 [vhost_net]
[ 2055.327337]  vhost_worker+0xa5/0x100 [vhost]
[ 2055.331646]  kthread+0xf5/0x130
[ 2055.334813]  ? vhost_dev_ioctl+0x3b0/0x3b0 [vhost]
[ 2055.339646]  ? kthread_bind+0x10/0x10
[ 2055.343343]  ret_from_fork+0x35/0x40
[ 2055.346950] Code: 0e 74 15 83 f8 10 75 05 e9 e9 aa b3 ff f3 c3 0f 1f 80 00 00 00 00 f3 c3 e9 c9 9d b3 ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <8b> 47 18 83 f8 0e 74 0d 83 f8 10 75 05 e9 e9 a9 b3 ff 31 c0 c3
[ 2055.366004] RIP: __xdp_map_lookup_elem+0x5/0x30 RSP: ffff998b07607cc0
[ 2055.372500] CR2: 0000000000000018
[ 2055.375856] ---[ end trace 2a2dcc5e9e174268 ]---
[ 2055.523626] Kernel panic - not syncing: Fatal exception
[ 2055.529796] Kernel Offset: 0x2e000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[ 2055.677539] ---[ end Kernel panic - not syncing: Fatal exception ]---

v2:
 - Removed preempt_disable/enable since local_bh_disable will prevent
   preemption as well, feedback from Jason Wang.

Fixes: 761876c857 ("tap: XDP support")
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-29 11:00:14 -04:00