Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The sparse commit 6002ded74587 ("add a flag to warn on casts to/from
bitwise pointers") introduced a check for non-direct casts from/to
restricted datatypes (when -Wbitwise-pointer is enabled).

This triggered various warnings in batman-adv when some (already big
endian) buffer content was casted to/from the corresponding big endian
integer data types. But these were correct and can therefore be marked with
__force to signalize sparse an intended cast from/to a bitwise type.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

Some wifi drivers (e.g. ath10k) provide per-station rx/tx values but no
estimated throughput. Setting a better estimate than the default 1 MBit
makes these devices work well with B.A.T.M.A.N. V.
Signed-off-by: NRené Treffer <treffer@measite.de>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The commit 43756e34 ("scripts/kernel-doc: Add support for named
variable macro arguments") changed the handling of variable macro
parameters. The three dots of the argument must no longer be added to the
kernel doc. The support for the old format is scheduled to be removed in
the future.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The commit ab92d68f ("net: core: add generic lockdep keys") removed
all lockdep functionality from soft-interface.c but didn't remove the
include for this functionality.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The usage of the '/* fall through */' comments in switches are no longer
marked as non-deprecated variant of implicit fall throughs for switch
statements. The commit 294f69e6 ("compiler_attributes.h: Add
'fallthrough' pseudo keyword for switch/case use") introduced a replacement
keyword which should be used instead.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

'aggr_list.lock' can safely be used in place of another explicit spinlock
when access to 'aggr_list' has to be guarded.

This avoids to take 2 locks, knowing that the 2nd one is always successful.

Now that the 'aggr_list.lock' is handled explicitly, the lock-free
__sbk_something() variants should be used when dealing with 'aggr_list'.
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

Use 'skb_queue_purge()' instead of re-implementing it.
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

When netdevice with offloaded BPF programs is destroyed
the programs are orphaned and removed from the program
IDA - their IDs get released (the programs may remain
accessible via existing open file descriptors and pinned
files). After IDs are released they are set to 0.

This confuses dev_change_xdp_fd() because it compares
the __dev_xdp_query() result where 0 means no program
with prog->aux->id where 0 means orphaned.

dev_change_xdp_fd() would have incorrectly returned success
even though it had not installed the program.

Since drivers already catch this case via bpf_offload_dev_match()
let them handle this case. The error message drivers produce in
this case ("program loaded for a different device") is in fact
correct as the orphaned program must had to be loaded for a
different device.

Fixes: c14a9f63 ("net: Don't call XDP_SETUP_PROG when nothing is changed")
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 40119211 ("net: sched: refactor block offloads counter
usage") missed the fact that either new prog or old prog may be
NULL.

Fixes: 40119211 ("net: sched: refactor block offloads counter usage")
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Historically linux tried to stick to RFC 791, 1122, 2003
for IPv4 ID field generation.

RFC 6864 made clear that no matter how hard we try,
we can not ensure unicity of IP ID within maximum
lifetime for all datagrams with a given source
address/destination address/protocol tuple.

Linux uses a per socket inet generator (inet_id), initialized
at connection startup with a XOR of 'jiffies' and other
fields that appear clear on the wire.

Thiemo Nagel pointed that this strategy is a privacy
concern as this provides 16 bits of entropy to fingerprint
devices.

Let's switch to a random starting point, this is just as
good as far as RFC 6864 is concerned and does not leak
anything critical.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NThiemo Nagel <tnagel@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcp_max_syn_backlog default value depends on memory size
and TCP ehash size. Before this patch, the max value
was 2048 [1], which is considered too small nowadays.

Increase it to 4096 to match the recent SOMAXCONN change.

[1] This is with TCP ehash size being capped to 524288 buckets.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Yue Cao <ycao009@ucr.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When rxrpc_recvmsg_data() sets the return value to 1 because it's drained
all the data for the last packet, it checks the last-packet flag on the
whole packet - but this is wrong, since the last-packet flag is only set on
the final subpacket of the last jumbo packet.  This means that a call that
receives its last packet in a jumbo packet won't complete properly.

Fix this by having rxrpc_locate_data() determine the last-packet state of
the subpacket it's looking at and passing that back to the caller rather
than having the caller look in the packet header.  The caller then needs to
cache this in the rxrpc_call struct as rxrpc_locate_data() isn't then
called again for this packet.

Fixes: 248f219c ("rxrpc: Rewrite the data and ack handling code")
Fixes: e2de6c40 ("rxrpc: Use info in skbuff instead of reparsing a jumbo packet")
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This socket field can be read and written by concurrent cpus.

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

KCSAN reported :

BUG: KCSAN: data-race in tcp_v4_rcv / tcp_v4_rcv

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

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

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When we're destroying the host transport mechanism, we should ensure
that we do not leak memory by failing to release any back channel
slots that might still exist.
Reported-by: NNeil Brown <neilb@suse.de>
Reported-by: Nkbuild test robot <lkp@intel.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If there are RDMA back channel requests being processed by the
server threads, then we should hold a reference to the transport
to ensure it doesn't get freed from underneath us.
Reported-by: NNeil Brown <neilb@suse.de>
Fixes: 63cae470 ("xprtrdma: Handle incoming backward direction RPC calls")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If there are TCP back channel requests being processed by the
server threads, then we should hold a reference to the transport
to ensure it doesn't get freed from underneath us.
Reported-by: NNeil Brown <neilb@suse.de>
Fixes: 2ea24497 ("SUNRPC: RPC callbacks may be split across several..")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Mesh path nexthop should be a ethernet address, but current validation
checks against 4 byte integers.

Cc: stable@vger.kernel.org
Fixes: 2ec600d6 ("nl80211/cfg80211: support for mesh, sta dumping")
Signed-off-by: NMarkus Theil <markus.theil@tu-ilmenau.de>
Link: https://lore.kernel.org/r/20191029093003.10355-1-markus.theil@tu-ilmenau.deSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

This patch disables setting of HT20 and more for channel 14 because
the channel is only for IEEE 802.11b.

The patch for net/wireless/util.c was unit-tested.

The patch for net/wireless/chan.c was tested with iw command.

Before this patch.
$ sudo iw dev <ifname> set channel 14 HT20
$

After this patch.
$ sudo iw dev <ifname> set channel 14 HT20
kernel reports: invalid channel definition
command failed: Invalid argument (-22)
$
Signed-off-by: NMasashi Honma <masashi.honma@gmail.com>
Link: https://lore.kernel.org/r/20191021075045.2719-1-masashi.honma@gmail.com
[clean up the code, use != instead of equivalent >]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

A simple typo fix in the nl error message (fbd -> fdb).

CC: David Ahern <dsahern@gmail.com>
Fixes: 8c6e137f ("rtnetlink: Update rtnl_fdb_dump for strict data checking")
Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a nonblocking socket is immediately closed after connect(),
the connect worker may not have started. This results in a refcount
problem, since sock_hold() is called from the connect worker.
This patch moves the sock_hold in front of the connect worker
scheduling.

Reported-by: syzbot+4c063e6dea39e4b79f29@syzkaller.appspotmail.com
Fixes: 50717a37 ("net/smc: nonblocking connect rework")
Reviewed-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The check for !md doens't really work for ip_tunnel_info_opts(info) which
only does info + 1. Also to avoid out-of-bounds access on info, it should
ensure options_len is not less than erspan_metadata in both erspan_xmit()
and ip6erspan_tunnel_xmit().

Fixes: 1a66a836 ("gre: add collect_md mode to ERSPAN tunnel")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

KCSAN reported a data-race in udp_set_dev_scratch() [1]

The issue here is that we must not write over skb fields
if skb is shared. A similar issue has been fixed in commit
89c22d8c ("net: Fix skb csum races when peeking")

While we are at it, use a helper only dealing with
udp_skb_scratch(skb)->csum_unnecessary, as this allows
udp_set_dev_scratch() to be called once and thus inlined.

[1]
BUG: KCSAN: data-race in udp_set_dev_scratch / udpv6_recvmsg

write to 0xffff888120278317 of 1 bytes by task 10411 on cpu 1:
 udp_set_dev_scratch+0xea/0x200 net/ipv4/udp.c:1308
 __first_packet_length+0x147/0x420 net/ipv4/udp.c:1556
 first_packet_length+0x68/0x2a0 net/ipv4/udp.c:1579
 udp_poll+0xea/0x110 net/ipv4/udp.c:2720
 sock_poll+0xed/0x250 net/socket.c:1256
 vfs_poll include/linux/poll.h:90 [inline]
 do_select+0x7d0/0x1020 fs/select.c:534
 core_sys_select+0x381/0x550 fs/select.c:677
 do_pselect.constprop.0+0x11d/0x160 fs/select.c:759
 __do_sys_pselect6 fs/select.c:784 [inline]
 __se_sys_pselect6 fs/select.c:769 [inline]
 __x64_sys_pselect6+0x12e/0x170 fs/select.c:769
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888120278317 of 1 bytes by task 10413 on cpu 0:
 udp_skb_csum_unnecessary include/net/udp.h:358 [inline]
 udpv6_recvmsg+0x43e/0xe90 net/ipv6/udp.c:310
 inet6_recvmsg+0xbb/0x240 net/ipv6/af_inet6.c:592
 sock_recvmsg_nosec+0x5c/0x70 net/socket.c:871
 ___sys_recvmsg+0x1a0/0x3e0 net/socket.c:2480
 do_recvmmsg+0x19a/0x5c0 net/socket.c:2601
 __sys_recvmmsg+0x1ef/0x200 net/socket.c:2680
 __do_sys_recvmmsg net/socket.c:2703 [inline]
 __se_sys_recvmmsg net/socket.c:2696 [inline]
 __x64_sys_recvmmsg+0x89/0xb0 net/socket.c:2696
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10413 Comm: syz-executor.0 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 2276f58a ("udp: use a separate rx queue for packet reception")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

__skb_wait_for_more_packets() can be called while other cpus
can feed packets to the socket receive queue.

KCSAN reported :

BUG: KCSAN: data-race in __skb_wait_for_more_packets / __udp_enqueue_schedule_skb

write to 0xffff888102e40b58 of 8 bytes by interrupt on cpu 0:
 __skb_insert include/linux/skbuff.h:1852 [inline]
 __skb_queue_before include/linux/skbuff.h:1958 [inline]
 __skb_queue_tail include/linux/skbuff.h:1991 [inline]
 __udp_enqueue_schedule_skb+0x2d7/0x410 net/ipv4/udp.c:1470
 __udp_queue_rcv_skb net/ipv4/udp.c:1940 [inline]
 udp_queue_rcv_one_skb+0x7bd/0xc70 net/ipv4/udp.c:2057
 udp_queue_rcv_skb+0xb5/0x400 net/ipv4/udp.c:2074
 udp_unicast_rcv_skb.isra.0+0x7e/0x1c0 net/ipv4/udp.c:2233
 __udp4_lib_rcv+0xa44/0x17c0 net/ipv4/udp.c:2300
 udp_rcv+0x2b/0x40 net/ipv4/udp.c:2470
 ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
 process_backlog+0x1d3/0x420 net/core/dev.c:5955

read to 0xffff888102e40b58 of 8 bytes by task 13035 on cpu 1:
 __skb_wait_for_more_packets+0xfa/0x320 net/core/datagram.c:100
 __skb_recv_udp+0x374/0x500 net/ipv4/udp.c:1683
 udp_recvmsg+0xe1/0xb10 net/ipv4/udp.c:1712
 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838
 sock_recvmsg_nosec+0x5c/0x70 net/socket.c:871
 ___sys_recvmsg+0x1a0/0x3e0 net/socket.c:2480
 do_recvmmsg+0x19a/0x5c0 net/socket.c:2601
 __sys_recvmmsg+0x1ef/0x200 net/socket.c:2680
 __do_sys_recvmmsg net/socket.c:2703 [inline]
 __se_sys_recvmmsg net/socket.c:2696 [inline]
 __x64_sys_recvmmsg+0x89/0xb0 net/socket.c:2696
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13035 Comm: syz-executor.3 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Busy polling usually runs without locks.
Let's use skb_queue_empty_lockless() instead of skb_queue_empty()

Also uses READ_ONCE() in __skb_try_recv_datagram() to address
a similar potential problem.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Many poll() handlers are lockless. Using skb_queue_empty_lockless()
instead of skb_queue_empty() is more appropriate.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

syzbot reported a data-race [1].

We should use skb_queue_empty_lockless() to document that we are
not ensuring a mutual exclusion and silence KCSAN.

[1]
BUG: KCSAN: data-race in __skb_recv_udp / __udp_enqueue_schedule_skb

write to 0xffff888122474b50 of 8 bytes by interrupt on cpu 0:
 __skb_insert include/linux/skbuff.h:1852 [inline]
 __skb_queue_before include/linux/skbuff.h:1958 [inline]
 __skb_queue_tail include/linux/skbuff.h:1991 [inline]
 __udp_enqueue_schedule_skb+0x2c1/0x410 net/ipv4/udp.c:1470
 __udp_queue_rcv_skb net/ipv4/udp.c:1940 [inline]
 udp_queue_rcv_one_skb+0x7bd/0xc70 net/ipv4/udp.c:2057
 udp_queue_rcv_skb+0xb5/0x400 net/ipv4/udp.c:2074
 udp_unicast_rcv_skb.isra.0+0x7e/0x1c0 net/ipv4/udp.c:2233
 __udp4_lib_rcv+0xa44/0x17c0 net/ipv4/udp.c:2300
 udp_rcv+0x2b/0x40 net/ipv4/udp.c:2470
 ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
 process_backlog+0x1d3/0x420 net/core/dev.c:5955

read to 0xffff888122474b50 of 8 bytes by task 8921 on cpu 1:
 skb_queue_empty include/linux/skbuff.h:1494 [inline]
 __skb_recv_udp+0x18d/0x500 net/ipv4/udp.c:1653
 udp_recvmsg+0xe1/0xb10 net/ipv4/udp.c:1712
 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838
 sock_recvmsg_nosec+0x5c/0x70 net/socket.c:871
 ___sys_recvmsg+0x1a0/0x3e0 net/socket.c:2480
 do_recvmmsg+0x19a/0x5c0 net/socket.c:2601
 __sys_recvmmsg+0x1ef/0x200 net/socket.c:2680
 __do_sys_recvmmsg net/socket.c:2703 [inline]
 __se_sys_recvmmsg net/socket.c:2696 [inline]
 __x64_sys_recvmmsg+0x89/0xb0 net/socket.c:2696
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8921 Comm: syz-executor.4 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit af4d768a ("net/ipv4: Add support for specifying metric
of connected routes"), when updating an IP address with a different metric,
the associated connected route is updated, too.

Still, the mentioned commit doesn't handle properly some corner cases:

$ ip addr add dev eth0 192.168.1.0/24
$ ip addr add dev eth0 192.168.2.1/32 peer 192.168.2.2
$ ip addr add dev eth0 192.168.3.1/24
$ ip addr change dev eth0 192.168.1.0/24 metric 10
$ ip addr change dev eth0 192.168.2.1/32 peer 192.168.2.2 metric 10
$ ip addr change dev eth0 192.168.3.1/24 metric 10
$ ip -4 route
192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.0
192.168.2.2 dev eth0 proto kernel scope link src 192.168.2.1
192.168.3.0/24 dev eth0 proto kernel scope link src 192.168.2.1 metric 10

Only the last route is correctly updated.

The problem is the current test in fib_modify_prefix_metric():

	if (!(dev->flags & IFF_UP) ||
	    ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
	    ipv4_is_zeronet(prefix) ||
	    prefix == ifa->ifa_local || ifa->ifa_prefixlen == 32)

Which should be the logical 'not' of the pre-existing test in
fib_add_ifaddr():

	if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
	    (prefix != addr || ifa->ifa_prefixlen < 32))

To properly negate the original expression, we need to change the last
logical 'or' to a logical 'and'.

Fixes: af4d768a ("net/ipv4: Add support for specifying metric of connected routes")
Reported-and-suggested-by: NBeniamino Galvani <bgalvani@redhat.com>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Reviewed-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

memset() the structure ethtool_wolinfo that has padded bytes
but the padded bytes have not been zeroed out.
Signed-off-by: Nzhanglin <zhang.lin16@zte.com.cn>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In rtnl_net_notifyid(), we certainly can't pass a null GFP flag to
rtnl_notify(). A GFP_KERNEL flag would be fine in most circumstances,
but there are a few paths calling rtnl_net_notifyid() from atomic
context or from RCU critical sections. The later also precludes the use
of gfp_any() as it wouldn't detect the RCU case. Also, the nlmsg_new()
call is wrong too, as it uses GFP_KERNEL unconditionally.

Therefore, we need to pass the GFP flags as parameter and propagate it
through function calls until the proper flags can be determined.

In most cases, GFP_KERNEL is fine. The exceptions are:
  * openvswitch: ovs_vport_cmd_get() and ovs_vport_cmd_dump()
    indirectly call rtnl_net_notifyid() from RCU critical section,

  * rtnetlink: rtmsg_ifinfo_build_skb() already receives GFP flags as
    parameter.

Also, in ovs_vport_cmd_build_info(), let's change the GFP flags used
by nlmsg_new(). The function is allowed to sleep, so better make the
flags consistent with the ones used in the following
ovs_vport_cmd_fill_info() call.

Found by code inspection.

Fixes: 9a963454 ("netns: notify netns id events")
Signed-off-by: NGuillaume Nault <gnault@redhat.com>
Acked-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: NPravin B Shelar <pshelar@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Creating of an SMC-R connection with vlan-id fails, because
smc_listen_work() determines the vlan_id of the connection,
saves it in struct smc_init_info ini, but clears the ini area
again if SMC-D is not applicable.
This patch just resets the ISM device before investigating
SMC-R availability.

Fixes: bc36d2fc ("net/smc: consolidate function parameters")
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For SMC sockets forced to fallback to TCP, the file is propagated
from the outer SMC to the internal TCP socket. When closing the SMC
socket, the internal TCP socket file pointer must be restored to the
original NULL value, otherwise memory leaks may show up (found with
CONFIG_DEBUG_KMEMLEAK).

The internal TCP socket is released in smc_clcsock_release(), which
calls __sock_release() function in net/socket.c. This calls the
needed iput(SOCK_INODE(sock)) only, if the file pointer has been reset
to the original NULL-value.

Fixes: 07603b23 ("net/smc: propagate file from SMC to TCP socket")
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is networking hardware that isn't based on Ethernet for layers 1 and 2.

For example CAN.

CAN is a multi-master serial bus standard for connecting Electronic Control
Units [ECUs] also known as nodes. A frame on the CAN bus carries up to 8 bytes
of payload. Frame corruption is detected by a CRC. However frame loss due to
corruption is possible, but a quite unusual phenomenon.

While fq_codel works great for TCP/IP, it doesn't for CAN. There are a lot of
legacy protocols on top of CAN, which are not build with flow control or high
CAN frame drop rates in mind.

When using fq_codel, as soon as the queue reaches a certain delay based length,
skbs from the head of the queue are silently dropped. Silently meaning that the
user space using a send() or similar syscall doesn't get an error. However
TCP's flow control algorithm will detect dropped packages and adjust the
bandwidth accordingly.

When using fq_codel and sending raw frames over CAN, which is the common use
case, the user space thinks the package has been sent without problems, because
send() returned without an error. pfifo_fast will drop skbs, if the queue
length exceeds the maximum. But with this scheduler the skbs at the tail are
dropped, an error (-ENOBUFS) is propagated to user space. So that the user
space can slow down the package generation.

On distributions, where fq_codel is made default via CONFIG_DEFAULT_NET_SCH
during compile time, or set default during runtime with sysctl
net.core.default_qdisc (see [1]), we get a bad user experience. In my test case
with pfifo_fast, I can transfer thousands of million CAN frames without a frame
drop. On the other hand with fq_codel there is more then one lost CAN frame per
thousand frames.

As pointed out fq_codel is not suited for CAN hardware, so this patch changes
attach_one_default_qdisc() to use pfifo_fast for "ARPHRD_CAN" network devices.

During transition of a netdev from down to up state the default queuing
discipline is attached by attach_default_qdiscs() with the help of
attach_one_default_qdisc(). This patch modifies attach_one_default_qdisc() to
attach the pfifo_fast (pfifo_fast_ops) if the network device type is
"ARPHRD_CAN".

[1] https://github.com/systemd/systemd/issues/9194Signed-off-by: NVincent Prince <vincent.prince.fr@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch removes variables and callback these are related to the nested
device structure.
devices that can be nested have their own nest_level variable that
represents the depth of nested devices.
In the previous patch, new {lower/upper}_level variables are added and
they replace old private nest_level variable.
So, this patch removes all 'nest_level' variables.

In order to avoid lockdep warning, ->ndo_get_lock_subclass() was added
to get lockdep subclass value, which is actually lower nested depth value.
But now, they use the dynamic lockdep key to avoid lockdep warning instead
of the subclass.
So, this patch removes ->ndo_get_lock_subclass() callback.
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to link an adjacent node, netdev_upper_dev_link() is used
and in order to unlink an adjacent node, netdev_upper_dev_unlink() is used.
unlink operation does not fail, but link operation can fail.

In order to exchange adjacent nodes, we should unlink an old adjacent
node first. then, link a new adjacent node.
If link operation is failed, we should link an old adjacent node again.
But this link operation can fail too.
It eventually breaks the adjacent link relationship.

This patch adds an ignore flag into the netdev_adjacent structure.
If this flag is set, netdev_upper_dev_link() ignores an old adjacent
node for a moment.

This patch also adds new functions for other modules.
netdev_adjacent_change_prepare()
netdev_adjacent_change_commit()
netdev_adjacent_change_abort()

netdev_adjacent_change_prepare() inserts new device into adjacent list
but new device is not allowed to use immediately.
If netdev_adjacent_change_prepare() fails, it internally rollbacks
adjacent list so that we don't need any other action.
netdev_adjacent_change_commit() deletes old device in the adjacent list
and allows new device to use.
netdev_adjacent_change_abort() rollbacks adjacent list.
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some interface types could be nested.
(VLAN, BONDING, TEAM, MACSEC, MACVLAN, IPVLAN, VIRT_WIFI, VXLAN, etc..)
These interface types should set lockdep class because, without lockdep
class key, lockdep always warn about unexisting circular locking.

In the current code, these interfaces have their own lockdep class keys and
these manage itself. So that there are so many duplicate code around the
/driver/net and /net/.
This patch adds new generic lockdep keys and some helper functions for it.

This patch does below changes.
a) Add lockdep class keys in struct net_device
   - qdisc_running, xmit, addr_list, qdisc_busylock
   - these keys are used as dynamic lockdep key.
b) When net_device is being allocated, lockdep keys are registered.
   - alloc_netdev_mqs()
c) When net_device is being free'd llockdep keys are unregistered.
   - free_netdev()
d) Add generic lockdep key helper function
   - netdev_register_lockdep_key()
   - netdev_unregister_lockdep_key()
   - netdev_update_lockdep_key()
e) Remove unnecessary generic lockdep macro and functions
f) Remove unnecessary lockdep code of each interfaces.

After this patch, each interface modules don't need to maintain
their lockdep keys.
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current code doesn't limit the number of nested devices.
Nested devices would be handled recursively and this needs huge stack
memory. So, unlimited nested devices could make stack overflow.

This patch adds upper_level and lower_level, they are common variables
and represent maximum lower/upper depth.
When upper/lower device is attached or dettached,
{lower/upper}_level are updated. and if maximum depth is bigger than 8,
attach routine fails and returns -EMLINK.

In addition, this patch converts recursive routine of
netdev_walk_all_{lower/upper} to iterator routine.

Test commands:
    ip link add dummy0 type dummy
    ip link add link dummy0 name vlan1 type vlan id 1
    ip link set vlan1 up

    for i in {2..55}
    do
	    let A=$i-1

	    ip link add vlan$i link vlan$A type vlan id $i
    done
    ip link del dummy0

Splat looks like:
[  155.513226][  T908] BUG: KASAN: use-after-free in __unwind_start+0x71/0x850
[  155.514162][  T908] Write of size 88 at addr ffff8880608a6cc0 by task ip/908
[  155.515048][  T908]
[  155.515333][  T908] CPU: 0 PID: 908 Comm: ip Not tainted 5.4.0-rc3+ #96
[  155.516147][  T908] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[  155.517233][  T908] Call Trace:
[  155.517627][  T908]
[  155.517918][  T908] Allocated by task 0:
[  155.518412][  T908] (stack is not available)
[  155.518955][  T908]
[  155.519228][  T908] Freed by task 0:
[  155.519885][  T908] (stack is not available)
[  155.520452][  T908]
[  155.520729][  T908] The buggy address belongs to the object at ffff8880608a6ac0
[  155.520729][  T908]  which belongs to the cache names_cache of size 4096
[  155.522387][  T908] The buggy address is located 512 bytes inside of
[  155.522387][  T908]  4096-byte region [ffff8880608a6ac0, ffff8880608a7ac0)
[  155.523920][  T908] The buggy address belongs to the page:
[  155.524552][  T908] page:ffffea0001822800 refcount:1 mapcount:0 mapping:ffff88806c657cc0 index:0x0 compound_mapcount:0
[  155.525836][  T908] flags: 0x100000000010200(slab|head)
[  155.526445][  T908] raw: 0100000000010200 ffffea0001813808 ffffea0001a26c08 ffff88806c657cc0
[  155.527424][  T908] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
[  155.528429][  T908] page dumped because: kasan: bad access detected
[  155.529158][  T908]
[  155.529410][  T908] Memory state around the buggy address:
[  155.530060][  T908]  ffff8880608a6b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  155.530971][  T908]  ffff8880608a6c00: fb fb fb fb fb f1 f1 f1 f1 00 f2 f2 f2 f3 f3 f3
[  155.531889][  T908] >ffff8880608a6c80: f3 fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  155.532806][  T908]                                            ^
[  155.533509][  T908]  ffff8880608a6d00: fb fb fb fb fb fb fb fb fb f1 f1 f1 f1 00 00 00
[  155.534436][  T908]  ffff8880608a6d80: f2 f3 f3 f3 f3 fb fb fb 00 00 00 00 00 00 00 00
[ ... ]
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>