Commits · 2f971a8f425545da52ca0e6bee81f5b1ea0ccc5f · Kirill Smelkov / linux

29 Dec, 2018 7 commits

netfilter: nf_conncount: move all list iterations under spinlock · 2f971a8f

Pablo Neira Ayuso authored Dec 28, 2018

Two CPUs may race to remove a connection from the list, the existing
conn->dead will result in a use-after-free. Use the per-list spinlock to
protect list iterations.

As all accesses to the list now happen while holding the per-list lock,
we no longer need to delay free operations with rcu.

Joint work with Florian.

Fixes: 5c789e13 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Reviewed-by: Shawn Bohrer <sbohrer@cloudflare.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

2f971a8f

netfilter: nf_conncount: merge lookup and add functions · df4a9025

Florian Westphal authored Dec 28, 2018

'lookup' is always followed by 'add'.
Merge both and make the list-walk part of nf_conncount_add().

This also avoids one unneeded unlock/re-lock pair.

Extra care needs to be taken in count_tree, as we only hold rcu
read lock, i.e. we can only insert to an existing tree node after
acquiring its lock and making sure it has a nonzero count.

As a zero count should be rare, just fall back to insert_tree()
(which acquires tree lock).

This issue and its solution were pointed out by Shawn Bohrer
during patch review.
Reviewed-by: Shawn Bohrer <sbohrer@cloudflare.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

df4a9025

netfilter: nf_conncount: restart search when nodes have been erased · e8cfb372

Florian Westphal authored Dec 28, 2018

Shawn Bohrer reported a following crash:
 |RIP: 0010:rb_erase+0xae/0x360
 [..]
 Call Trace:
  nf_conncount_destroy+0x59/0xc0 [nf_conncount]
  cleanup_match+0x45/0x70 [ip_tables]
  ...

Shawn tracked this down to bogus 'parent' pointer:
Problem is that when we insert a new node, then there is a chance that
the 'parent' that we found was also passed to tree_nodes_free() (because
that node was empty) for erase+free.

Instead of trying to be clever and detect when this happens, restart
the search if we have evicted one or more nodes.  To prevent frequent
restarts, do not perform gc on the second round.

Also, unconditionally schedule the gc worker.
The condition

  gc_count > ARRAY_SIZE(gc_nodes))

cannot be true unless tree grows very large, as the height of the tree
will be low even with hundreds of nodes present.

Fixes: 5c789e13 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Reported-by: Shawn Bohrer <sbohrer@cloudflare.com>
Reviewed-by: Shawn Bohrer <sbohrer@cloudflare.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

e8cfb372

netfilter: nf_conncount: split gc in two phases · f7fcc98d

Florian Westphal authored Dec 28, 2018

The lockless workqueue garbage collector can race with packet path
garbage collector to delete list nodes, as it calls tree_nodes_free()
with the addresses of nodes that might have been free'd already from
another cpu.

To fix this, split gc into two phases.

One phase to perform gc on the connections: From a locking perspective,
this is the same as count_tree(): we hold rcu lock, but we do not
change the tree, we only change the nodes' contents.

The second phase acquires the tree lock and reaps empty nodes.
This avoids a race condition of the garbage collection vs.  packet path:
If a node has been free'd already, the second phase won't find it anymore.

This second phase is, from locking perspective, same as insert_tree().

The former only modifies nodes (list content, count), latter modifies
the tree itself (rb_erase or rb_insert).

Fixes: 5c789e13 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Reviewed-by: Shawn Bohrer <sbohrer@cloudflare.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

f7fcc98d

netfilter: nf_conncount: don't skip eviction when age is negative · 4cd273bb

Florian Westphal authored Dec 28, 2018

age is signed integer, so result can be negative when the timestamps
have a large delta.  In this case we want to discard the entry.

Instead of using age >= 2 || age < 0, just make it unsigned.

Fixes: b36e4523 ("netfilter: nf_conncount: fix garbage collection confirm race")
Reviewed-by: Shawn Bohrer <sbohrer@cloudflare.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

4cd273bb

netfilter: nf_conncount: replace CONNCOUNT_LOCK_SLOTS with CONNCOUNT_SLOTS · c78e7818

Shawn Bohrer authored Dec 28, 2018

Most of the time these were the same value anyway, but when
CONFIG_LOCKDEP was enabled we would use a smaller number of locks to
reduce overhead.  Unfortunately having two values is confusing and not
worth the complexity.

This fixes a bug where tree_gc_worker() would only GC up to
CONNCOUNT_LOCK_SLOTS trees which meant when CONFIG_LOCKDEP was enabled
not all trees would be GCed by tree_gc_worker().

Fixes: 5c789e13 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Shawn Bohrer <sbohrer@cloudflare.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

c78e7818

netfilter: nf_tables: fix a missing check of nla_put_failure · eb895086

Kangjie Lu authored Dec 21, 2018

If nla_nest_start() may fail. The fix checks its return value and goes
to nla_put_failure if it fails.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

eb895086

28 Dec, 2018 13 commits

include/linux/phy/phy.h: fix minor kerneldoc errors · a3c9311f

Robert P. J. Day authored Dec 27, 2018

Correct two minor kerneldoc errors:

 1) missing reference to @mode in struct phy_ops
 2) obsolete reference to @init_data in struct_phy_attrs,
    removed in dbc98635Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>

a3c9311f

phy.h: fix obvious errors in doc and kerneldoc content · d8de01b7

Robert P. J. Day authored Dec 26, 2018

1) note that gianfar_phy.c was removed years ago
 2) fix obvious copy and paste error in regular doc
 3) change regular doc into kerneldoc for phy_modes()
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>

d8de01b7

net/wan/fsl_ucc_hdlc: Avoid double free in ucc_hdlc_probe() · 40752b3e

Wen Yang authored Dec 26, 2018

This patch fixes potential double frees if register_hdlc_device() fails.
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Reviewed-by: Peng Hao <peng.hao2@zte.com.cn>
CC: Zhao Qiang <qiang.zhao@nxp.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: netdev@vger.kernel.org
CC: linuxppc-dev@lists.ozlabs.org
CC: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

40752b3e

net: marvell: fix a missing check of acpi_match_device · 92ee77d1

Kangjie Lu authored Dec 26, 2018

When acpi_match_device fails, its return value is NULL. Directly using
the return value without a check may result in a NULL-pointer
dereference. The fix checks if acpi_match_device fails, and if so,
returns -EINVAL.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

92ee77d1

tipc: fix a missing check of genlmsg_put · 46273cf7

Kangjie Lu authored Dec 26, 2018

genlmsg_put could fail. The fix inserts a check of its return value, and
if it fails, returns -EMSGSIZE.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

46273cf7

atl1e: checking the status of atl1e_write_phy_reg · ff07d48d