syzkaller found another bug in DCCP/TCP stacks [1]

For the reasons explained in commit ce105008 ("tcp/dccp: fix
ireq->pktopts race"), we need to make sure we do not access
ireq->opt unless we own the request sock.

Note the opt field is renamed to ireq_opt to ease grep games.

[1]
BUG: KASAN: use-after-free in ip_queue_xmit+0x1687/0x18e0 net/ipv4/ip_output.c:474
Read of size 1 at addr ffff8801c951039c by task syz-executor5/3295

CPU: 1 PID: 3295 Comm: syz-executor5 Not tainted 4.14.0-rc4+ #80
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x25b/0x340 mm/kasan/report.c:409
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:427
 ip_queue_xmit+0x1687/0x18e0 net/ipv4/ip_output.c:474
 tcp_transmit_skb+0x1ab7/0x3840 net/ipv4/tcp_output.c:1135
 tcp_send_ack.part.37+0x3bb/0x650 net/ipv4/tcp_output.c:3587
 tcp_send_ack+0x49/0x60 net/ipv4/tcp_output.c:3557
 __tcp_ack_snd_check+0x2c6/0x4b0 net/ipv4/tcp_input.c:5072
 tcp_ack_snd_check net/ipv4/tcp_input.c:5085 [inline]
 tcp_rcv_state_process+0x2eff/0x4850 net/ipv4/tcp_input.c:6071
 tcp_child_process+0x342/0x990 net/ipv4/tcp_minisocks.c:816
 tcp_v4_rcv+0x1827/0x2f80 net/ipv4/tcp_ipv4.c:1682
 ip_local_deliver_finish+0x2e2/0xba0 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_local_deliver+0x1ce/0x6e0 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:464 [inline]
 ip_rcv_finish+0x887/0x19a0 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_rcv+0xc3f/0x1820 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x1a3e/0x34b0 net/core/dev.c:4476
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4514
 netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4587
 netif_receive_skb+0xae/0x390 net/core/dev.c:4611
 tun_rx_batched.isra.50+0x5ed/0x860 drivers/net/tun.c:1372
 tun_get_user+0x249c/0x36d0 drivers/net/tun.c:1766
 tun_chr_write_iter+0xbf/0x160 drivers/net/tun.c:1792
 call_write_iter include/linux/fs.h:1770 [inline]
 new_sync_write fs/read_write.c:468 [inline]
 __vfs_write+0x68a/0x970 fs/read_write.c:481
 vfs_write+0x18f/0x510 fs/read_write.c:543
 SYSC_write fs/read_write.c:588 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:580
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x40c341
RSP: 002b:00007f469523ec10 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 000000000040c341
RDX: 0000000000000037 RSI: 0000000020004000 RDI: 0000000000000015
RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000f4240 R11: 0000000000000293 R12: 00000000004b7fd1
R13: 00000000ffffffff R14: 0000000020000000 R15: 0000000000025000

Allocated by task 3295:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3725 [inline]
 __kmalloc+0x162/0x760 mm/slab.c:3734
 kmalloc include/linux/slab.h:498 [inline]
 tcp_v4_save_options include/net/tcp.h:1962 [inline]
 tcp_v4_init_req+0x2d3/0x3e0 net/ipv4/tcp_ipv4.c:1271
 tcp_conn_request+0xf6d/0x3410 net/ipv4/tcp_input.c:6283
 tcp_v4_conn_request+0x157/0x210 net/ipv4/tcp_ipv4.c:1313
 tcp_rcv_state_process+0x8ea/0x4850 net/ipv4/tcp_input.c:5857
 tcp_v4_do_rcv+0x55c/0x7d0 net/ipv4/tcp_ipv4.c:1482
 tcp_v4_rcv+0x2d10/0x2f80 net/ipv4/tcp_ipv4.c:1711
 ip_local_deliver_finish+0x2e2/0xba0 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_local_deliver+0x1ce/0x6e0 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:464 [inline]
 ip_rcv_finish+0x887/0x19a0 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_rcv+0xc3f/0x1820 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x1a3e/0x34b0 net/core/dev.c:4476
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4514
 netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4587
 netif_receive_skb+0xae/0x390 net/core/dev.c:4611
 tun_rx_batched.isra.50+0x5ed/0x860 drivers/net/tun.c:1372
 tun_get_user+0x249c/0x36d0 drivers/net/tun.c:1766
 tun_chr_write_iter+0xbf/0x160 drivers/net/tun.c:1792
 call_write_iter include/linux/fs.h:1770 [inline]
 new_sync_write fs/read_write.c:468 [inline]
 __vfs_write+0x68a/0x970 fs/read_write.c:481
 vfs_write+0x18f/0x510 fs/read_write.c:543
 SYSC_write fs/read_write.c:588 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:580
 entry_SYSCALL_64_fastpath+0x1f/0xbe

Freed by task 3306:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xca/0x250 mm/slab.c:3820
 inet_sock_destruct+0x59d/0x950 net/ipv4/af_inet.c:157
 __sk_destruct+0xfd/0x910 net/core/sock.c:1560
 sk_destruct+0x47/0x80 net/core/sock.c:1595
 __sk_free+0x57/0x230 net/core/sock.c:1603
 sk_free+0x2a/0x40 net/core/sock.c:1614
 sock_put include/net/sock.h:1652 [inline]
 inet_csk_complete_hashdance+0xd5/0xf0 net/ipv4/inet_connection_sock.c:959
 tcp_check_req+0xf4d/0x1620 net/ipv4/tcp_minisocks.c:765
 tcp_v4_rcv+0x17f6/0x2f80 net/ipv4/tcp_ipv4.c:1675
 ip_local_deliver_finish+0x2e2/0xba0 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_local_deliver+0x1ce/0x6e0 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:464 [inline]
 ip_rcv_finish+0x887/0x19a0 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_rcv+0xc3f/0x1820 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x1a3e/0x34b0 net/core/dev.c:4476
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4514
 netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4587
 netif_receive_skb+0xae/0x390 net/core/dev.c:4611
 tun_rx_batched.isra.50+0x5ed/0x860 drivers/net/tun.c:1372
 tun_get_user+0x249c/0x36d0 drivers/net/tun.c:1766
 tun_chr_write_iter+0xbf/0x160 drivers/net/tun.c:1792
 call_write_iter include/linux/fs.h:1770 [inline]
 new_sync_write fs/read_write.c:468 [inline]
 __vfs_write+0x68a/0x970 fs/read_write.c:481
 vfs_write+0x18f/0x510 fs/read_write.c:543
 SYSC_write fs/read_write.c:588 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:580
 entry_SYSCALL_64_fastpath+0x1f/0xbe

Fixes: e994b2f0 ("tcp: do not lock listener to process SYN packets")
Fixes: 079096f1 ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

John Fastabend says:

====================
sockmap fixes for net

The following implements a set of fixes for sockmap and changes the
API slightly in a few places to reduce preempt_disable/enable scope.
We do this here in net because it requires an API change and this
avoids getting stuck with legacy API going forward.

The short description:

Access to skb mark is removed, it is problematic when we add
features in the future because mark is a union and used by the
TCP/socket code internally. We don't want to expose this to the
BPF programs or let programs change the values.

The other change is caching metadata in the skb itself between
when the BPF program returns a redirect code and the core code
implements the redirect. This avoids having per cpu metadata.

Finally, tighten restriction on using sockmap to CAP_NET_ADMIN and
only SOCK_STREAM sockets.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Devmap is used with XDP which requires CAP_NET_ADMIN so lets also
make CAP_NET_ADMIN required to use the map.
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Restrict sockmap to CAP_NET_ADMIN.
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The skb->mark field is a union with reserved_tailroom which is used
in the TCP code paths from stream memory allocation. Allowing SK_SKB
programs to set this field creates a conflict with future code
optimizations, such as "gifting" the skb to the egress path instead
of creating a new skb and doing a memcpy.

Because we do not have a released version of SK_SKB yet lets just
remove it for now. A more appropriate scratch pad to use at the
socket layer is dev_scratch, but lets add that in future kernels
when needed.
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SK_SKB BPF programs are run from the socket/tcp context but early in
the stack before much of the TCP metadata is needed in tcp_skb_cb. So
we can use some unused fields to place BPF metadata needed for SK_SKB
programs when implementing the redirect function.

This allows us to drop the preempt disable logic. It does however
require an API change so sk_redirect_map() has been updated to
additionally provide ctx_ptr to skb. Note, we do however continue to
disable/enable preemption around actual BPF program running to account
for map updates.
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Only TCP sockets have been tested and at the moment the state change
callback only handles TCP sockets. This adds a check to ensure that
sockets actually being added are TCP sockets.

For net-next we can consider UDP support.
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now sctp processes icmp redirect packet in sctp_icmp_redirect where
it calls sctp_transport_dst_check in which tp->dst can be released.

The problem is before calling sctp_transport_dst_check, it doesn't
check sock_owned_by_user, which means tp->dst could be freed while
a process is accessing it with owning the socket.

An use-after-free issue could be triggered by this.

This patch is to fix it by checking sock_owned_by_user before calling
sctp_transport_dst_check in sctp_icmp_redirect, so that it would not
release tp->dst if users still hold sock lock.

Besides, the same issue fixed in commit 45caeaa5 ("dccp/tcp: fix
routing redirect race") on sctp also needs this check.

Fixes: 55be7a9c ("ipv4: Add redirect support to all protocol icmp error handlers")
Reported-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now when peeling off an association to the sock in another netns, all
transports in this assoc are not to be rehashed and keep use the old
key in hashtable.

As a transport uses sk->net as the hash key to insert into hashtable,
it would miss removing these transports from hashtable due to the new
netns when closing the sock and all transports are being freeed, then
later an use-after-free issue could be caused when looking up an asoc
and dereferencing those transports.

This is a very old issue since very beginning, ChunYu found it with
syzkaller fuzz testing with this series:

  socket$inet6_sctp()
  bind$inet6()
  sendto$inet6()
  unshare(0x40000000)
  getsockopt$inet_sctp6_SCTP_GET_ASSOC_ID_LIST()
  getsockopt$inet_sctp6_SCTP_SOCKOPT_PEELOFF()

This patch is to block this call when peeling one assoc off from one
netns to another one, so that the netns of all transport would not
go out-sync with the key in hashtable.

Note that this patch didn't fix it by rehashing transports, as it's
difficult to handle the situation when the tuple is already in use
in the new netns. Besides, no one would like to peel off one assoc
to another netns, considering ipaddrs, ifaces, etc. are usually
different.
Reported-by: NChunYu Wang <chunwang@redhat.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
bpf: Fix for BPF devmap percpu allocation splat

The set fixes a splat in devmap percpu allocation when we alloc
the flush bitmap. Patch 1 is a prerequisite for the fix in patch 2,
patch 1 is rather small, so if this could be routed via -net, for
example, with Tejun's Ack that would be good. Patch 3 gets rid of
remaining PCPU_MIN_UNIT_SIZE checks, which are percpu allocator
internals and should not be used.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

PCPU_MIN_UNIT_SIZE is an implementation detail of the percpu
allocator. Given we support __GFP_NOWARN now, lets just let
the allocation request fail naturally instead. The two call
sites from BPF mistakenly assumed __GFP_NOWARN would work, so
no changes needed to their actual __alloc_percpu_gfp() calls
which use the flag already.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It was reported that syzkaller was able to trigger a splat on
devmap percpu allocation due to illegal/unsupported allocation
request size passed to __alloc_percpu():

  [   70.094249] illegal size (32776) or align (8) for percpu allocation
  [   70.094256] ------------[ cut here ]------------
  [   70.094259] WARNING: CPU: 3 PID: 3451 at mm/percpu.c:1365 pcpu_alloc+0x96/0x630
  [...]
  [   70.094325] Call Trace:
  [   70.094328]  __alloc_percpu_gfp+0x12/0x20
  [   70.094330]  dev_map_alloc+0x134/0x1e0
  [   70.094331]  SyS_bpf+0x9bc/0x1610
  [   70.094333]  ? selinux_task_setrlimit+0x5a/0x60
  [   70.094334]  ? security_task_setrlimit+0x43/0x60
  [   70.094336]  entry_SYSCALL_64_fastpath+0x1a/0xa5

This was due to too large max_entries for the map such that we
surpassed the upper limit of PCPU_MIN_UNIT_SIZE. It's fine to
fail naturally here, so switch to __alloc_percpu_gfp() and pass
__GFP_NOWARN instead.

Fixes: 11393cc9 ("xdp: Add batching support to redirect map")
Reported-by: NMark Rutland <mark.rutland@arm.com>
Reported-by: NShankara Pailoor <sp3485@columbia.edu>
Reported-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.fastabend@gmail.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add an option for pcpu_alloc() to support __GFP_NOWARN flag.
Currently, we always throw a warning when size or alignment
is unsupported (and also dump stack on failed allocation
requests). The warning itself is harmless since we return
NULL anyway for any failed request, which callers are
required to handle anyway. However, it becomes harmful when
panic_on_warn is set.

The rationale for the WARN() in pcpu_alloc() is that it can
be tracked when larger than supported allocation requests are
made such that allocations limits can be tweaked if warranted.
This makes sense for in-kernel users, however, there are users
of pcpu allocator where allocation size is derived from user
space requests, e.g. when creating BPF maps. In these cases,
the requests should fail gracefully without throwing a splat.

The current work-around was to check allocation size against
the upper limit of PCPU_MIN_UNIT_SIZE from call-sites for
bailing out prior to a call to pcpu_alloc() in order to
avoid throwing the WARN(). This is bad in multiple ways since
PCPU_MIN_UNIT_SIZE is an implementation detail, and having
the checks on call-sites only complicates the code for no
good reason. Thus, lets fix it generically by supporting the
__GFP_NOWARN flag that users can then use with calling the
__alloc_percpu_gfp() helper instead.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Netanel Belgazal says:

====================
ENA ethernet driver bug fixes

Some fixes for ENA ethernet driver
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ethtool ena_get_channels() expose the max number of queues as the max
number of queues ENA supports (128 queues) and not the actual number
of created queues.
Signed-off-by: NNetanel Belgazal <netanel@amazon.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This failure is rare and only found on testing where deliberately fail
devm_ioremap()

[  451.170464] ena 0000:04:00.0: failed to remap regs bar
451.170549] Workqueue: pciehp-1 pciehp_power_thread
[  451.170551] task: ffff88085a5f2d00 task.stack: ffffc9000756c000
[  451.170552] RIP: 0010:devm_iounmap+0x2d/0x40
[  451.170553] RSP: 0018:ffffc9000756fac0 EFLAGS: 00010282
[  451.170554] RAX: 00000000fffffffe RBX: 0000000000000000 RCX:
0000000000000000
[  451.170555] RDX: ffffffff813a7e00 RSI: 0000000000000282 RDI:
0000000000000282
[  451.170556] RBP: ffffc9000756fac8 R08: 00000000fffffffe R09:
00000000000009b7
[  451.170557] R10: 0000000000000005 R11: 00000000000009b6 R12:
ffff880856c9d0a0
[  451.170558] R13: ffffc9000f5c90c0 R14: ffff880856c9d0a0 R15:
0000000000000028
[  451.170559] FS:  0000000000000000(0000) GS:ffff88085f400000(0000)
knlGS:0000000000000000
[  451.170560] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  451.170561] CR2: 00007f169038b000 CR3: 0000000001c09000 CR4:
00000000003406f0
[  451.170562] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[  451.170562] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[  451.170563] Call Trace:
[  451.170572]  ena_release_bars.isra.48+0x34/0x60 [ena]
[  451.170574]  ena_probe+0x144/0xd90 [ena]
[  451.170579]  ? ida_simple_get+0x98/0x100
[  451.170585]  ? kernfs_next_descendant_post+0x40/0x50
[  451.170591]  local_pci_probe+0x45/0xa0
[  451.170592]  pci_device_probe+0x157/0x180
[  451.170599]  driver_probe_device+0x2a8/0x460
[  451.170600]  __device_attach_driver+0x7e/0xe0
[  451.170602]  ? driver_allows_async_probing+0x30/0x30
[  451.170603]  bus_for_each_drv+0x68/0xb0
[  451.170605]  __device_attach+0xdd/0x160
[  451.170607]  device_attach+0x10/0x20
[  451.170610]  pci_bus_add_device+0x4f/0xa0
[  451.170611]  pci_bus_add_devices+0x39/0x70
[  451.170613]  pciehp_configure_device+0x96/0x120
[  451.170614]  pciehp_enable_slot+0x1b3/0x290
[  451.170616]  pciehp_power_thread+0x3b/0xb0
[  451.170622]  process_one_work+0x149/0x360
[  451.170623]  worker_thread+0x4d/0x3c0
[  451.170626]  kthread+0x109/0x140
[  451.170627]  ? rescuer_thread+0x380/0x380
[  451.170628]  ? kthread_park+0x60/0x60
[  451.170632]  ret_from_fork+0x25/0x30
Signed-off-by: NNetanel Belgazal <netanel@amazon.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Decrease log level of checksum errors as these messages can be
triggered remotely by bad packets.
Signed-off-by: NNetanel Belgazal <netanel@amazon.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit f1174f77 ("bpf/verifier: rework value tracking")
removed the crafty selection of which pointer types are
allowed to be modified.  This is OK for most pointer types
since adjust_ptr_min_max_vals() will catch operations on
immutable pointers.  One exception is PTR_TO_CTX which is
now allowed to be offseted freely.

The intent of aforementioned commit was to allow context
access via modified registers.  The offset passed to
->is_valid_access() verifier callback has been adjusted
by the value of the variable offset.

What is missing, however, is taking the variable offset
into account when the context register is used.  Or in terms
of the code adding the offset to the value passed to the
->convert_ctx_access() callback.  This leads to the following
eBPF user code:

     r1 += 68
     r0 = *(u32 *)(r1 + 8)
     exit

being translated to this in kernel space:

   0: (07) r1 += 68
   1: (61) r0 = *(u32 *)(r1 +180)
   2: (95) exit

Offset 8 is corresponding to 180 in the kernel, but offset
76 is valid too.  Verifier will "accept" access to offset
68+8=76 but then "convert" access to offset 8 as 180.
Effective access to offset 248 is beyond the kernel context.
(This is a __sk_buff example on a debug-heavy kernel -
packet mark is 8 -> 180, 76 would be data.)

Dereferencing the modified context pointer is not as easy
as dereferencing other types, because we have to translate
the access to reading a field in kernel structures which is
usually at a different offset and often of a different size.
To allow modifying the pointer we would have to make sure
that given eBPF instruction will always access the same
field or the fields accessed are "compatible" in terms of
offset and size...

Disallow dereferencing modified context pointers and add
to selftests the test case described here.

Fixes: f1174f77 ("bpf/verifier: rework value tracking")
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NEdward Cree <ecree@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It seems that it's possible to toggle NETLINK_F_EXT_ACK
through setsockopt() while another thread/CPU is building
a message inside netlink_ack(), which could then trigger
the WARN_ON()s I added since if it goes from being turned
off to being turned on between allocating and filling the
message, the skb could end up being too small.

Avoid this whole situation by storing the value of this
flag in a separate variable and using that throughout the
function instead.

Fixes: 2d4bc933 ("netlink: extended ACK reporting")
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch correctly sets the number of additional header descriptors
that will be sent in an indirect SCRQ entry.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When an EMAD is transmitted, a timeout work item is scheduled with a
delay of 200ms, so that another EMAD will be retried until a maximum of
five retries.

In certain situations, it's possible for the function waiting on the
EMAD to be associated with a work item that is queued on the same
workqueue (`mlxsw_core`) as the timeout work item. This results in
flushing a work item on the same workqueue.

According to commit e159489b ("workqueue: relax lockdep annotation
on flush_work()") the above may lead to a deadlock in case the workqueue
has only one worker active or if the system in under memory pressure and
the rescue worker is in use. The latter explains the very rare and
random nature of the lockdep splats we have been seeing:

[   52.730240] ============================================
[   52.736179] WARNING: possible recursive locking detected
[   52.742119] 4.14.0-rc3jiri+ #4 Not tainted
[   52.746697] --------------------------------------------
[   52.752635] kworker/1:3/599 is trying to acquire lock:
[   52.758378]  (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c4fa4>] flush_work+0x3a4/0x5e0
[   52.767837]
               but task is already holding lock:
[   52.774360]  (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0
[   52.784495]
               other info that might help us debug this:
[   52.791794]  Possible unsafe locking scenario:
[   52.798413]        CPU0
[   52.801144]        ----
[   52.803875]   lock(mlxsw_core_driver_name);
[   52.808556]   lock(mlxsw_core_driver_name);
[   52.813236]
                *** DEADLOCK ***
[   52.819857]  May be due to missing lock nesting notation
[   52.827450] 3 locks held by kworker/1:3/599:
[   52.832221]  #0:  (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0
[   52.842846]  #1:  ((&(&bridge->fdb_notify.dw)->work)){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0
[   52.854537]  #2:  (rtnl_mutex){+.+.}, at: [<ffffffff822ad8e7>] rtnl_lock+0x17/0x20
[   52.863021]
               stack backtrace:
[   52.867890] CPU: 1 PID: 599 Comm: kworker/1:3 Not tainted 4.14.0-rc3jiri+ #4
[   52.875773] Hardware name: Mellanox Technologies Ltd. "MSN2100-CB2F"/"SA001017", BIOS 5.6.5 06/07/2016
[   52.886267] Workqueue: mlxsw_core mlxsw_sp_fdb_notify_work [mlxsw_spectrum]
[   52.894060] Call Trace:
[   52.909122]  __lock_acquire+0xf6f/0x2a10
[   53.025412]  lock_acquire+0x158/0x440
[   53.047557]  flush_work+0x3c4/0x5e0
[   53.087571]  __cancel_work_timer+0x3ca/0x5e0
[   53.177051]  cancel_delayed_work_sync+0x13/0x20
[   53.182142]  mlxsw_reg_trans_bulk_wait+0x12d/0x7a0 [mlxsw_core]
[   53.194571]  mlxsw_core_reg_access+0x586/0x990 [mlxsw_core]
[   53.225365]  mlxsw_reg_query+0x10/0x20 [mlxsw_core]
[   53.230882]  mlxsw_sp_fdb_notify_work+0x2a3/0x9d0 [mlxsw_spectrum]
[   53.237801]  process_one_work+0x8f1/0x12f0
[   53.321804]  worker_thread+0x1fd/0x10c0
[   53.435158]  kthread+0x28e/0x370
[   53.448703]  ret_from_fork+0x2a/0x40
[   53.453017] mlxsw_spectrum 0000:01:00.0: EMAD retries (2/5) (tid=bf4549b100000774)
[   53.453119] mlxsw_spectrum 0000:01:00.0: EMAD retries (5/5) (tid=bf4549b100000770)
[   53.453132] mlxsw_spectrum 0000:01:00.0: EMAD reg access failed (tid=bf4549b100000770,reg_id=200b(sfn),type=query,status=0(operation performed))
[   53.453143] mlxsw_spectrum 0000:01:00.0: Failed to get FDB notifications

Fix this by creating another workqueue for EMAD timeouts, thereby
preventing the situation of a work item trying to flush a work item
queued on the same workqueue.

Fixes: caf7297e ("mlxsw: core: Introduce support for asynchronous EMAD register access")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reported-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Merge tag 'mac80211-for-davem-2017-10-16' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

Johannes Berg says:

====================
Just a single fix, for a WoWLAN-related part of CVE-2017-13080.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When changing dev tx_queue_len via netlink or net-sysfs,
a NETDEV_CHANGE_TX_QUEUE_LEN event notification will be
called.

But dev_ioctl missed this event notification, which could
cause no userspace notification would be sent.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 7091d8c7 '(net/sched: cls_flower: Add offload support using egress
Hardware device') made sure (when fl_hw_replace_filter is called) to put
the egress_dev mark on persisent structure instance. Hence, following calls
into the HW driver for stats and deletion will note it and act accordingly.

With commit de4784ca this property is lost and hence when called,
the HW driver failes to operate (stats, delete) on the offloaded flow.

Fix it by setting the egress_dev flag whenever the ingress device is
different from the hw device since this is exactly the condition under
which we're calling into the HW driver through the egress port net-device.

Fixes: de4784ca ('net: sched: get rid of struct tc_to_netdev')
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoi Dayan <roid@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

register_netdevice() could fail early when we have an invalid
dev name, in which case ->ndo_uninit() is not called. For tun
device, this is a problem because a timer etc. are already
initialized and it expects ->ndo_uninit() to clean them up.

We could move these initializations into a ->ndo_init() so
that register_netdevice() knows better, however this is still
complicated due to the logic in tun_detach().

Therefore, I choose to just call dev_get_valid_name() before
register_netdevice(), which is quicker and much easier to audit.
And for this specific case, it is already enough.

Fixes: 96442e42 ("tuntap: choose the txq based on rxq")
Reported-by: NDmitry Alexeev <avekceeb@gmail.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IFLA_IFALIAS is defined as NLA_STRING. It means that the minimal length of
the attribute is 1 ("\0"). However, to remove an alias, the attribute
length must be 0 (see dev_set_alias()).

Let's define the type to NLA_BINARY to allow 0-length string, so that the
alias can be removed.

Example:
$ ip l s dummy0 alias foo
$ ip l l dev dummy0
5: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether ae:20:30:4f:a7:f3 brd ff:ff:ff:ff:ff:ff
    alias foo

Before the patch:
$ ip l s dummy0 alias ""
RTNETLINK answers: Numerical result out of range

After the patch:
$ ip l s dummy0 alias ""
$ ip l l dev dummy0
5: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether ae:20:30:4f:a7:f3 brd ff:ff:ff:ff:ff:ff

CC: Oliver Hartkopp <oliver@hartkopp.net>
CC: Stephen Hemminger <stephen@networkplumber.org>
Fixes: 96ca4a2c ("net: remove ifalias on empty given alias")
Reported-by: NJulien FLoret <julien.floret@6wind.com>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Xin Long says:

====================
rtnetlink: a bunch of fixes for userspace notifications in changing dev properties

Whenever any property of a link, address, route, etc. changes by whatever way,
kernel should notify the programs that listen for such events in userspace.

The patchet "rtnetlink: Cleanup user notifications for netdev events" tried to
fix a redundant notifications issue, but it also introduced a side effect.

After that, user notifications could only be sent when changing dev properties
via netlink api. As it removed some events process in rtnetlink_event where
the notifications was sent to users.

It resulted in no notification generated when dev properties are changed via
other ways, like ioctl, sysfs, etc. It may cause some user programs doesn't
work as expected because of the missing notifications.

This patchset will fix it by bringing some of these netdev events back and
also fix the old redundant notifications issue with a proper way.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

NETDEV_CHANGE_TX_QUEUE_LEN event process in rtnetlink_event would
send a notification for userspace and tx_queue_len's setting in
do_setlink would trigger NETDEV_CHANGE_TX_QUEUE_LEN.

So it shouldn't set DO_SETLINK_NOTIFY status for this change to
send a notification any more.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The check 'status & DO_SETLINK_NOTIFY' in do_setlink doesn't really
work after status & DO_SETLINK_MODIFIED, as:

  DO_SETLINK_MODIFIED 0x1
  DO_SETLINK_NOTIFY 0x3

Considering that notifications are suppposed to be sent only when
status have the flag DO_SETLINK_NOTIFY, the right check would be:

  (status & DO_SETLINK_NOTIFY) == DO_SETLINK_NOTIFY

This would avoid lots of duplicated notifications when setting some
properties of a link.

Fixes: ba998906 ("rtnl/do_setlink(): notify when a netdev is modified")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

libteam needs this event notification in userspace when dev's master
dev has been changed. After this, the redundant notifications issue
would be fixed in the later patch 'rtnetlink: check DO_SETLINK_NOTIFY
correctly in do_setlink'.

Fixes: b6b36eb2 ("rtnetlink: Do not generate notifications for NETDEV_CHANGEUPPER event")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As I said in patch 'rtnetlink: bring NETDEV_CHANGEMTU event process back
in rtnetlink_event', removing NETDEV_POST_TYPE_CHANGE event was not the
right fix for the redundant notifications issue.

So bring this event process back to rtnetlink_event and the old redundant
notifications issue would be fixed in the later patch 'rtnetlink: check
DO_SETLINK_NOTIFY correctly in do_setlink'.

Fixes: aef091ae ("rtnetlink: Do not generate notifications for POST_TYPE_CHANGE event")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The same fix for changing mtu in the patch 'rtnetlink: bring
NETDEV_CHANGEMTU event process back in rtnetlink_event' is
needed for changing tx_queue_len.

Note that the redundant notifications issue for tx_queue_len
will be fixed in the later patch 'rtnetlink: do not send
notification for tx_queue_len in do_setlink'.

Fixes: 27b3b551 ("rtnetlink: Do not generate notifications for NETDEV_CHANGE_TX_QUEUE_LEN event")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 085e1a65 ("rtnetlink: Do not generate notifications for MTU
events") tried to fix the redundant notifications issue when ip link
set mtu by removing NETDEV_CHANGEMTU event process in rtnetlink_event.

But it also resulted in no notification generated when dev's mtu is
changed via other methods, like:
  'ifconfig eth1 mtu 1400' or 'echo 1400 > /sys/class/net/eth1/mtu'
It would cause users not to be notified by this change.

This patch is to fix it by bringing NETDEV_CHANGEMTU event back into
rtnetlink_event, and the redundant notifications issue will be fixed
in the later patch 'rtnetlink: check DO_SETLINK_NOTIFY correctly in
do_setlink'.

Fixes: 085e1a65 ("rtnetlink: Do not generate notifications for MTU events")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a key is reinstalled we can reset the replay counters
etc. which can lead to nonce reuse and/or replay detection
being impossible, breaking security properties, as described
in the "KRACK attacks".

In particular, CVE-2017-13080 applies to GTK rekeying that
happened in firmware while the host is in D3, with the second
part of the attack being done after the host wakes up. In
this case, the wpa_supplicant mitigation isn't sufficient
since wpa_supplicant doesn't know the GTK material.

In case this happens, simply silently accept the new key
coming from userspace but don't take any action on it since
it's the same key; this keeps the PN replay counters intact.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Michael Chan says:

====================
bnxt_en: bug fixes.

Various bug fixes for the VF/PF link change logic, VF resource checking,
potential firmware response corruption on NVRAM and DCB parameters,
and reading the wrong register for PCIe link speed on the VF.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

hwrm_send_message() is replaced with _hwrm_send_message(), and
hwrm_cmd_lock mutex lock is grabbed for the whole period of
firmware call until the firmware DCB parameters have been copied.
This will prevent possible corruption of the firmware data.

Fixes: 7df4ae9f ("bnxt_en: Implement DCBNL to support host-based DCBX.")
Signed-off-by: NSankar Patchineelam <sankar.patchineelam@broadcom.com>
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In bnxt_find_nvram_item(), it is copying firmware response data after
releasing the mutex.  This can cause the firmware response data
to be corrupted if the next firmware response overwrites the response
buffer.  The rare problem shows up when running ethtool -i repeatedly.

Fix it by calling the new variant _hwrm_send_message_silent() that requires
the caller to take the mutex and to release it after the response data has
been copied.

Fixes: 3ebf6f0a ("bnxt_en: Add installed-package version reporting via Ethtool GDRVINFO")
Reported-by: NSarveswara Rao Mygapula <sarveswararao.mygapula@broadcom.com>
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In bnxt_sriov_enable(), we calculate to see if we have enough hardware
resources to enable the requested number of VFs.  The logic to check
for minimum completion rings and statistics contexts is missing.  Add
the required checks so that VF configuration won't fail.
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

PCIE PCIE_EP_REG_LINK_STATUS_CONTROL register is only defined in PF
config space, so we must read it from the PF.

Fixes: 90c4f788 ("bnxt_en: Report PCIe link speed and width during driver load")
Signed-off-by: NVasundhara Volam <vasundhara-v.volam@broadcom.com>
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As a further improvement to the PF/VF link change logic, use a private
mutex instead of the rtnl lock to protect link change logic.  With the
new mutex, we don't have to take the rtnl lock in the workqueue when
we have to handle link related functions.  If the VF and PF drivers
are running on the same host and both take the rtnl lock and one is
waiting for the other, it will cause timeout.  This patch fixes these
timeouts.

Fixes: 90c694bb ("bnxt_en: Fix RTNL lock usage on bnxt_update_link().")
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>