linux-stable.git/net/core, branch v4.4.282

net: Fix zero-copy head len calculation.

2021-08-08T06:37:47+00:00

[ Upstream commit a17ad0961706244dce48ec941f7e476a38c0e727 ]

In some cases skb head could be locked and entire header
data is pulled from skb. When skb_zerocopy() called in such cases,
following BUG is triggered. This patch fixes it by copying entire
skb in such cases.
This could be optimized incase this is performance bottleneck.

---8<---
kernel BUG at net/core/skbuff.c:2961!
invalid opcode: 0000 [#1] SMP PTI
CPU: 2 PID: 0 Comm: swapper/2 Tainted: G           OE     5.4.0-77-generic #86-Ubuntu
Hardware name: OpenStack Foundation OpenStack Nova, BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:skb_zerocopy+0x37a/0x3a0
RSP: 0018:ffffbcc70013ca38 EFLAGS: 00010246
Call Trace:
 
 queue_userspace_packet+0x2af/0x5e0 [openvswitch]
 ovs_dp_upcall+0x3d/0x60 [openvswitch]
 ovs_dp_process_packet+0x125/0x150 [openvswitch]
 ovs_vport_receive+0x77/0xd0 [openvswitch]
 netdev_port_receive+0x87/0x130 [openvswitch]
 netdev_frame_hook+0x4b/0x60 [openvswitch]
 __netif_receive_skb_core+0x2b4/0xc90
 __netif_receive_skb_one_core+0x3f/0xa0
 __netif_receive_skb+0x18/0x60
 process_backlog+0xa9/0x160
 net_rx_action+0x142/0x390
 __do_softirq+0xe1/0x2d6
 irq_exit+0xae/0xb0
 do_IRQ+0x5a/0xf0
 common_interrupt+0xf/0xf

Code that triggered BUG:
int
skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen)
{
        int i, j = 0;
        int plen = 0; /* length of skb->head fragment */
        int ret;
        struct page *page;
        unsigned int offset;

        BUG_ON(!from->head_frag && !hlen);

Signed-off-by: Pravin B Shelar 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: Treat __napi_schedule_irqoff() as __napi_schedule() on PREEMPT_RT

2021-07-20T14:22:37+00:00

[ Upstream commit 8380c81d5c4fced6f4397795a5ae65758272bbfd ]

__napi_schedule_irqoff() is an optimized version of __napi_schedule()
which can be used where it is known that interrupts are disabled,
e.g. in interrupt-handlers, spin_lock_irq() sections or hrtimer
callbacks.

On PREEMPT_RT enabled kernels this assumptions is not true. Force-
threaded interrupt handlers and spinlocks are not disabling interrupts
and the NAPI hrtimer callback is forced into softirq context which runs
with interrupts enabled as well.

Chasing all usage sites of __napi_schedule_irqoff() is a whack-a-mole
game so make __napi_schedule_irqoff() invoke __napi_schedule() for
PREEMPT_RT kernels.

The callers of ____napi_schedule() in the networking core have been
audited and are correct on PREEMPT_RT kernels as well.

Reported-by: Juri Lelli 
Signed-off-by: Sebastian Andrzej Siewior 
Reviewed-by: Thomas Gleixner 
Reviewed-by: Juri Lelli 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

rtnetlink: Fix regression in bridge VLAN configuration

2021-06-30T12:49:32+00:00

[ Upstream commit d2e381c4963663bca6f30c3b996fa4dbafe8fcb5 ]

Cited commit started returning errors when notification info is not
filled by the bridge driver, resulting in the following regression:

 # ip link add name br1 type bridge vlan_filtering 1
 # bridge vlan add dev br1 vid 555 self pvid untagged
 RTNETLINK answers: Invalid argument

As long as the bridge driver does not fill notification info for the
bridge device itself, an empty notification should not be considered as
an error. This is explained in commit 59ccaaaa49b5 ("bridge: dont send
notification when skb->len == 0 in rtnl_bridge_notify").

Fix by removing the error and add a comment to avoid future bugs.

Fixes: a8db57c1d285 ("rtnetlink: Fix missing error code in rtnl_bridge_notify()")
Signed-off-by: Ido Schimmel 
Reviewed-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

fib: Return the correct errno code

2021-06-30T12:49:31+00:00

[ Upstream commit 59607863c54e9eb3f69afc5257dfe71c38bb751e ]

When kalloc or kmemdup failed, should return ENOMEM rather than ENOBUF.

Signed-off-by: Zheng Yongjun 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

rtnetlink: Fix missing error code in rtnl_bridge_notify()

2021-06-30T12:49:31+00:00

[ Upstream commit a8db57c1d285c758adc7fb43d6e2bad2554106e1 ]

The error code is missing in this code scenario, add the error code
'-EINVAL' to the return value 'err'.

Eliminate the follow smatch warning:

net/core/rtnetlink.c:4834 rtnl_bridge_notify() warn: missing error code
'err'.

Reported-by: Abaci Robot 
Signed-off-by: Jiapeng Chong 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

neighbour: Disregard DEAD dst in neigh_update

2021-04-28T10:05:45+00:00

[ Upstream commit d47ec7a0a7271dda08932d6208e4ab65ab0c987c ]

After a short network outage, the dst_entry is timed out and put
in DST_OBSOLETE_DEAD. We are in this code because arp reply comes
from this neighbour after network recovers. There is a potential
race condition that dst_entry is still in DST_OBSOLETE_DEAD.
With that, another neighbour lookup causes more harm than good.

In best case all packets in arp_queue are lost. This is
counterproductive to the original goal of finding a better path
for those packets.

I observed a worst case with 4.x kernel where a dst_entry in
DST_OBSOLETE_DEAD state is associated with loopback net_device.
It leads to an ethernet header with all zero addresses.
A packet with all zero source MAC address is quite deadly with
mac80211, ath9k and 802.11 block ack.  It fails
ieee80211_find_sta_by_ifaddr in ath9k (xmit.c). Ath9k flushes tx
queue (ath_tx_complete_aggr). BAW (block ack window) is not
updated. BAW logic is damaged and ath9k transmission is disabled.

Signed-off-by: Tong Zhu 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

can: dev: Move device back to init netns on owning netns delete

2021-03-30T12:45:01+00:00

commit 3a5ca857079ea022e0b1b17fc154f7ad7dbc150f upstream.

When a non-initial netns is destroyed, the usual policy is to delete
all virtual network interfaces contained, but move physical interfaces
back to the initial netns. This keeps the physical interface visible
on the system.

CAN devices are somewhat special, as they define rtnl_link_ops even
if they are physical devices. If a CAN interface is moved into a
non-initial netns, destroying that netns lets the interface vanish
instead of moving it back to the initial netns. default_device_exit()
skips CAN interfaces due to having rtnl_link_ops set. Reproducer:

  ip netns add foo
  ip link set can0 netns foo
  ip netns delete foo

WARNING: CPU: 1 PID: 84 at net/core/dev.c:11030 ops_exit_list+0x38/0x60
CPU: 1 PID: 84 Comm: kworker/u4:2 Not tainted 5.10.19 #1
Workqueue: netns cleanup_net
[] (unwind_backtrace) from [] (show_stack+0x10/0x14)
[] (show_stack) from [] (dump_stack+0x94/0xa8)
[] (dump_stack) from [] (__warn+0xb8/0x114)
[] (__warn) from [] (warn_slowpath_fmt+0x7c/0xac)
[] (warn_slowpath_fmt) from [] (ops_exit_list+0x38/0x60)
[] (ops_exit_list) from [] (cleanup_net+0x230/0x380)
[] (cleanup_net) from [] (process_one_work+0x1d8/0x438)
[] (process_one_work) from [] (worker_thread+0x64/0x5a8)
[] (worker_thread) from [] (kthread+0x148/0x14c)
[] (kthread) from [] (ret_from_fork+0x14/0x2c)

To properly restore physical CAN devices to the initial netns on owning
netns exit, introduce a flag on rtnl_link_ops that can be set by drivers.
For CAN devices setting this flag, default_device_exit() considers them
non-virtual, applying the usual namespace move.

The issue was introduced in the commit mentioned below, as at that time
CAN devices did not have a dellink() operation.

Fixes: e008b5fc8dc7 ("net: Simplfy default_device_exit and improve batching.")
Link: https://lore.kernel.org/r/20210302122423.872326-1-martin@strongswan.org
Signed-off-by: Martin Willi 
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Greg Kroah-Hartman

pktgen: fix misuse of BUG_ON() in pktgen_thread_worker()

2021-03-07T10:24:21+00:00

[ Upstream commit 275b1e88cabb34dbcbe99756b67e9939d34a99b6 ]

pktgen create threads for all online cpus and bond these threads to
relevant cpu repecivtily. when this thread firstly be woken up, it
will compare cpu currently running with the cpu specified at the time
of creation and if the two cpus are not equal, BUG_ON() will take effect
causing panic on the system.
Notice that these threads could be migrated to other cpus before start
running because of the cpu hotplug after these threads have created. so the
BUG_ON() used here seems unreasonable and we can replace it with WARN_ON()
to just printf a warning other than panic the system.

Signed-off-by: Di Zhu 
Link: https://lore.kernel.org/r/20210125124229.19334-1-zhudi21@huawei.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net: fix up truesize of cloned skb in skb_prepare_for_shift()

2021-03-07T10:24:20+00:00

commit 097b9146c0e26aabaa6ff3e5ea536a53f5254a79 upstream.

Avoid the assumption that ksize(kmalloc(S)) == ksize(kmalloc(S)): when
cloning an skb, save and restore truesize after pskb_expand_head(). This
can occur if the allocator decides to service an allocation of the same
size differently (e.g. use a different size class, or pass the
allocation on to KFENCE).

Because truesize is used for bookkeeping (such as sk_wmem_queued), a
modified truesize of a cloned skb may result in corrupt bookkeeping and
relevant warnings (such as in sk_stream_kill_queues()).

Link: https://lkml.kernel.org/r/X9JR/J6dMMOy1obu@elver.google.com
Reported-by: syzbot+7b99aafdcc2eedea6178@syzkaller.appspotmail.com
Suggested-by: Eric Dumazet 
Signed-off-by: Marco Elver 
Signed-off-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20210201160420.2826895-1-elver@google.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

skbuff: back tiny skbs with kmalloc() in __netdev_alloc_skb() too

2021-01-30T12:25:57+00:00

commit 66c556025d687dbdd0f748c5e1df89c977b6c02a upstream.

Commit 3226b158e67c ("net: avoid 32 x truesize under-estimation for
tiny skbs") ensured that skbs with data size lower than 1025 bytes
will be kmalloc'ed to avoid excessive page cache fragmentation and
memory consumption.
However, the fix adressed only __napi_alloc_skb() (primarily for
virtio_net and napi_get_frags()), but the issue can still be achieved
through __netdev_alloc_skb(), which is still used by several drivers.
Drivers often allocate a tiny skb for headers and place the rest of
the frame to frags (so-called copybreak).
Mirror the condition to __netdev_alloc_skb() to handle this case too.

Since v1 [0]:
 - fix "Fixes:" tag;
 - refine commit message (mention copybreak usecase).

[0] https://lore.kernel.org/netdev/20210114235423.232737-1-alobakin@pm.me

Fixes: a1c7fff7e18f ("net: netdev_alloc_skb() use build_skb()")
Signed-off-by: Alexander Lobakin 
Link: https://lore.kernel.org/r/20210115150354.85967-1-alobakin@pm.me
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman