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  1. 02 Oct, 2020 4 commits
    • Coly Li's avatar
      net: introduce helper sendpage_ok() in include/linux/net.h · c381b079
      Coly Li authored 
      The original problem was from nvme-over-tcp code, who mistakenly uses
kernel_sendpage() to send pages allocated by __get_free_pages() without
__GFP_COMP flag. Such pages don't have refcount (page_count is 0) on
tail pages, sending them by kernel_sendpage() may trigger a kernel panic
from a corrupted kernel heap, because these pages are incorrectly freed
in network stack as page_count 0 pages.

This patch introduces a helper sendpage_ok(), it returns true if the
checking page,
- is not slab page: PageSlab(page) is false.
- has page refcount: page_count(page) is not zero

All drivers who want to send page to remote end by kernel_sendpage()
may use this helper to check whether the page is OK. If the helper does
not return true, the driver should try other non sendpage method (e.g.
sock_no_sendpage()) to handle the page.
Signed-off-by: default avatarColy Li <colyli@suse.de>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Jan Kara <jack@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mikhail Skorzhinskii <mskorzhinskiy@solarflare.com>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Vlastimil Babka <vbabka@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c381b079
    • Petko Manolov's avatar
      net: usb: pegasus: Proper error handing when setting pegasus' MAC address · f30e25a9
      Petko Manolov authored 
      v2:

If reading the MAC address from eeprom fail don't throw an error, use randomly
generated MAC instead.  Either way the adapter will soldier on and the return
type of set_ethernet_addr() can be reverted to void.

v1:

Fix a bug in set_ethernet_addr() which does not take into account possible
errors (or partial reads) returned by its helpers.  This can potentially lead to
writing random data into device's MAC address registers.
Signed-off-by: default avatarPetko Manolov <petko.manolov@konsulko.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f30e25a9
    • Mauro Carvalho Chehab's avatar
      net: core: document two new elements of struct net_device · a93bdcb9
      Mauro Carvalho Chehab authored 
      As warned by "make htmldocs", there are two new struct elements
that aren't documented:

	../include/linux/netdevice.h:2159: warning: Function parameter or member 'unlink_list' not described in 'net_device'
	../include/linux/netdevice.h:2159: warning: Function parameter or member 'nested_level' not described in 'net_device'

Fixes: 1fc70edb ("net: core: add nested_level variable in net_device")
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a93bdcb9
    • Johannes Berg's avatar
      netlink: fix policy dump leak · a95bc734
      Johannes Berg authored 
      If userspace doesn't complete the policy dump, we leak the
allocated state. Fix this.

Fixes: d07dcf9a ("netlink: add infrastructure to expose policies to userspace")
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Reviewed-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a95bc734
  3. 01 Oct, 2020 2 commits
  5. 30 Sep, 2020 12 commits
  7. 29 Sep, 2020 16 commits
  9. 28 Sep, 2020 6 commits
    • Manivannan Sadhasivam's avatar
      net: qrtr: ns: Protect radix_tree_deref_slot() using rcu read locks · a7809ff9
      Manivannan Sadhasivam authored 
      The rcu read locks are needed to avoid potential race condition while
dereferencing radix tree from multiple threads. The issue was identified
by syzbot. Below is the crash report:

=============================
WARNING: suspicious RCU usage
5.7.0-syzkaller #0 Not tainted
-----------------------------
include/linux/radix-tree.h:176 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
2 locks held by kworker/u4:1/21:
 #0: ffff88821b097938 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: spin_unlock_irq include/linux/spinlock.h:403 [inline]
 #0: ffff88821b097938 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: process_one_work+0x6df/0xfd0 kernel/workqueue.c:2241
 #1: ffffc90000dd7d80 ((work_completion)(&qrtr_ns.work)){+.+.}-{0:0}, at: process_one_work+0x71e/0xfd0 kernel/workqueue.c:2243

stack backtrace:
CPU: 0 PID: 21 Comm: kworker/u4:1 Not tainted 5.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: qrtr_ns_handler qrtr_ns_worker
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1e9/0x30e lib/dump_stack.c:118
 radix_tree_deref_slot include/linux/radix-tree.h:176 [inline]
 ctrl_cmd_new_lookup net/qrtr/ns.c:558 [inline]
 qrtr_ns_worker+0x2aff/0x4500 net/qrtr/ns.c:674
 process_one_work+0x76e/0xfd0 kernel/workqueue.c:2268
 worker_thread+0xa7f/0x1450 kernel/workqueue.c:2414
 kthread+0x353/0x380 kernel/kthread.c:268

Fixes: 0c2204a4 ("net: qrtr: Migrate nameservice to kernel from userspace")
Reported-and-tested-by: syzbot+0f84f6eed90503da72fc@syzkaller.appspotmail.com
Signed-off-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a7809ff9
    • David S. Miller's avatar
      Merge branch 'net-core-fix-a-lockdep-splat-in-the-dev_addr_list' · 0ba56b89
      David S. Miller authored 
      Taehee Yoo says:

====================
net: core: fix a lockdep splat in the dev_addr_list.

This patchset is to avoid lockdep splat.

When a stacked interface graph is changed, netif_addr_lock() is called
recursively and it internally calls spin_lock_nested().
The parameter of spin_lock_nested() is 'dev->lower_level',
this is called subclass.
The problem of 'dev->lower_level' is that while 'dev->lower_level' is
being used as a subclass of spin_lock_nested(), its value can be changed.
So, spin_lock_nested() would be called recursively with the same
subclass value, the lockdep understands a deadlock.
In order to avoid this, a new variable is needed and it is going to be
used as a parameter of spin_lock_nested().
The first and second patch is a preparation patch for the third patch.
In the third patch, the problem will be fixed.

The first patch is to add __netdev_upper_dev_unlink().
An existed netdev_upper_dev_unlink() is renamed to
__netdev_upper_dev_unlink(). and netdev_upper_dev_unlink()
is added as an wrapper of this function.

The second patch is to add the netdev_nested_priv structure.
netdev_walk_all_{ upper | lower }_dev() pass both private functions
and "data" pointer to handle their own things.
At this point, the data pointer type is void *.
In order to make it easier to expand common variables and functions,
this new netdev_nested_priv structure is added.

The third patch is to add a new variable 'nested_level'
into the net_device structure.
This variable will be used as a parameter of spin_lock_nested() of
dev->addr_list_lock.
Due to this variable, it can avoid lockdep splat.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      0ba56b89
    • Taehee Yoo's avatar
      net: core: add nested_level variable in net_device · 1fc70edb
      Taehee Yoo authored 
      This patch is to add a new variable 'nested_level' into the net_device
structure.
This variable will be used as a parameter of spin_lock_nested() of
dev->addr_list_lock.

netif_addr_lock() can be called recursively so spin_lock_nested() is
used instead of spin_lock() and dev->lower_level is used as a parameter
of spin_lock_nested().
But, dev->lower_level value can be updated while it is being used.
So, lockdep would warn a possible deadlock scenario.

When a stacked interface is deleted, netif_{uc | mc}_sync() is
called recursively.
So, spin_lock_nested() is called recursively too.
At this moment, the dev->lower_level variable is used as a parameter of it.
dev->lower_level value is updated when interfaces are being unlinked/linked
immediately.
Thus, After unlinking, dev->lower_level shouldn't be a parameter of
spin_lock_nested().

    A (macvlan)
    |
    B (vlan)
    |
    C (bridge)
    |
    D (macvlan)
    |
    E (vlan)
    |
    F (bridge)

    A->lower_level : 6
    B->lower_level : 5
    C->lower_level : 4
    D->lower_level : 3
    E->lower_level : 2
    F->lower_level : 1

When an interface 'A' is removed, it releases resources.
At this moment, netif_addr_lock() would be called.
Then, netdev_upper_dev_unlink() is called recursively.
Then dev->lower_level is updated.
There is no problem.

But, when the bridge module is removed, 'C' and 'F' interfaces
are removed at once.
If 'F' is removed first, a lower_level value is like below.
    A->lower_level : 5
    B->lower_level : 4
    C->lower_level : 3
    D->lower_level : 2
    E->lower_level : 1
    F->lower_level : 1

Then, 'C' is removed. at this moment, netif_addr_lock() is called
recursively.
The ordering is like this.
C(3)->D(2)->E(1)->F(1)
At this moment, the lower_level value of 'E' and 'F' are the same.
So, lockdep warns a possible deadlock scenario.

In order to avoid this problem, a new variable 'nested_level' is added.
This value is the same as dev->lower_level - 1.
But this value is updated in rtnl_unlock().
So, this variable can be used as a parameter of spin_lock_nested() safely
in the rtnl context.

Test commands:
   ip link add br0 type bridge vlan_filtering 1
   ip link add vlan1 link br0 type vlan id 10
   ip link add macvlan2 link vlan1 type macvlan
   ip link add br3 type bridge vlan_filtering 1
   ip link set macvlan2 master br3
   ip link add vlan4 link br3 type vlan id 10
   ip link add macvlan5 link vlan4 type macvlan
   ip link add br6 type bridge vlan_filtering 1
   ip link set macvlan5 master br6
   ip link add vlan7 link br6 type vlan id 10
   ip link add macvlan8 link vlan7 type macvlan

   ip link set br0 up
   ip link set vlan1 up
   ip link set macvlan2 up
   ip link set br3 up
   ip link set vlan4 up
   ip link set macvlan5 up
   ip link set br6 up
   ip link set vlan7 up
   ip link set macvlan8 up
   modprobe -rv bridge

Splat looks like:
[   36.057436][  T744] WARNING: possible recursive locking detected
[   36.058848][  T744] 5.9.0-rc6+ #728 Not tainted
[   36.059959][  T744] --------------------------------------------
[   36.061391][  T744] ip/744 is trying to acquire lock:
[   36.062590][  T744] ffff8c4767509280 (&vlan_netdev_addr_lock_key){+...}-{2:2}, at: dev_set_rx_mode+0x19/0x30
[   36.064922][  T744]
[   36.064922][  T744] but task is already holding lock:
[   36.066626][  T744] ffff8c4767769280 (&vlan_netdev_addr_lock_key){+...}-{2:2}, at: dev_uc_add+0x1e/0x60
[   36.068851][  T744]
[   36.068851][  T744] other info that might help us debug this:
[   36.070731][  T744]  Possible unsafe locking scenario:
[   36.070731][  T744]
[   36.072497][  T744]        CPU0
[   36.073238][  T744]        ----
[   36.074007][  T744]   lock(&vlan_netdev_addr_lock_key);
[   36.075290][  T744]   lock(&vlan_netdev_addr_lock_key);
[   36.076590][  T744]
[   36.076590][  T744]  *** DEADLOCK ***
[   36.076590][  T744]
[   36.078515][  T744]  May be due to missing lock nesting notation
[   36.078515][  T744]
[   36.080491][  T744] 3 locks held by ip/744:
[   36.081471][  T744]  #0: ffffffff98571df0 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x236/0x490
[   36.083614][  T744]  #1: ffff8c4767769280 (&vlan_netdev_addr_lock_key){+...}-{2:2}, at: dev_uc_add+0x1e/0x60
[   36.085942][  T744]  #2: ffff8c476c8da280 (&bridge_netdev_addr_lock_key/4){+...}-{2:2}, at: dev_uc_sync+0x39/0x80
[   36.088400][  T744]
[   36.088400][  T744] stack backtrace:
[   36.089772][  T744] CPU: 6 PID: 744 Comm: ip Not tainted 5.9.0-rc6+ #728
[   36.091364][  T744] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[   36.093630][  T744] Call Trace:
[   36.094416][  T744]  dump_stack+0x77/0x9b
[   36.095385][  T744]  __lock_acquire+0xbc3/0x1f40
[   36.096522][  T744]  lock_acquire+0xb4/0x3b0
[   36.097540][  T744]  ? dev_set_rx_mode+0x19/0x30
[   36.098657][  T744]  ? rtmsg_ifinfo+0x1f/0x30
[   36.099711][  T744]  ? __dev_notify_flags+0xa5/0xf0
[   36.100874][  T744]  ? rtnl_is_locked+0x11/0x20
[   36.101967][  T744]  ? __dev_set_promiscuity+0x7b/0x1a0
[   36.103230][  T744]  _raw_spin_lock_bh+0x38/0x70
[   36.104348][  T744]  ? dev_set_rx_mode+0x19/0x30
[   36.105461][  T744]  dev_set_rx_mode+0x19/0x30
[   36.106532][  T744]  dev_set_promiscuity+0x36/0x50
[   36.107692][  T744]  __dev_set_promiscuity+0x123/0x1a0
[   36.108929][  T744]  dev_set_promiscuity+0x1e/0x50
[   36.110093][  T744]  br_port_set_promisc+0x1f/0x40 [bridge]
[   36.111415][  T744]  br_manage_promisc+0x8b/0xe0 [bridge]
[   36.112728][  T744]  __dev_set_promiscuity+0x123/0x1a0
[   36.113967][  T744]  ? __hw_addr_sync_one+0x23/0x50
[   36.115135][  T744]  __dev_set_rx_mode+0x68/0x90
[   36.116249][  T744]  dev_uc_sync+0x70/0x80
[   36.117244][  T744]  dev_uc_add+0x50/0x60
[   36.118223][  T744]  macvlan_open+0x18e/0x1f0 [macvlan]
[   36.119470][  T744]  __dev_open+0xd6/0x170
[   36.120470][  T744]  __dev_change_flags+0x181/0x1d0
[   36.121644][  T744]  dev_change_flags+0x23/0x60
[   36.122741][  T744]  do_setlink+0x30a/0x11e0
[   36.123778][  T744]  ? __lock_acquire+0x92c/0x1f40
[   36.124929][  T744]  ? __nla_validate_parse.part.6+0x45/0x8e0
[   36.126309][  T744]  ? __lock_acquire+0x92c/0x1f40
[   36.127457][  T744]  __rtnl_newlink+0x546/0x8e0
[   36.128560][  T744]  ? lock_acquire+0xb4/0x3b0
[   36.129623][  T744]  ? deactivate_slab.isra.85+0x6a1/0x850
[   36.130946][  T744]  ? __lock_acquire+0x92c/0x1f40
[   36.132102][  T744]  ? lock_acquire+0xb4/0x3b0
[   36.133176][  T744]  ? is_bpf_text_address+0x5/0xe0
[   36.134364][  T744]  ? rtnl_newlink+0x2e/0x70
[   36.135445][  T744]  ? rcu_read_lock_sched_held+0x32/0x60
[   36.136771][  T744]  ? kmem_cache_alloc_trace+0x2d8/0x380
[   36.138070][  T744]  ? rtnl_newlink+0x2e/0x70
[   36.139164][  T744]  rtnl_newlink+0x47/0x70
[ ... ]

Fixes: 845e0ebb ("net: change addr_list_lock back to static key")
Signed-off-by: default avatarTaehee Yoo <ap420073@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1fc70edb
    • Taehee Yoo's avatar
      net: core: introduce struct netdev_nested_priv for nested interface infrastructure · eff74233
      Taehee Yoo authored 
      Functions related to nested interface infrastructure such as
netdev_walk_all_{ upper | lower }_dev() pass both private functions
and "data" pointer to handle their own things.
At this point, the data pointer type is void *.
In order to make it easier to expand common variables and functions,
this new netdev_nested_priv structure is added.

In the following patch, a new member variable will be added into this
struct to fix the lockdep issue.
Signed-off-by: default avatarTaehee Yoo <ap420073@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      eff74233
    • Taehee Yoo's avatar
      net: core: add __netdev_upper_dev_unlink() · fe8300fd
      Taehee Yoo authored 
      The netdev_upper_dev_unlink() has to work differently according to flags.
This idea is the same with __netdev_upper_dev_link().

In the following patches, new flags will be added.
Signed-off-by: default avatarTaehee Yoo <ap420073@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      fe8300fd
    • Cong Wang's avatar
      net_sched: remove a redundant goto chain check · 1aad8049
      Cong Wang authored 
      All TC actions call tcf_action_check_ctrlact() to validate
goto chain, so this check in tcf_action_init_1() is actually
redundant. Remove it to save troubles of leaking memory.

Fixes: e49d8c22 ("net_sched: defer tcf_idr_insert() in tcf_action_init_1()")
Reported-by: default avatarVlad Buslov <vladbu@mellanox.com>
Suggested-by: default avatarDavide Caratti <dcaratti@redhat.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: default avatarDavide Caratti <dcaratti@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1aad8049
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