We can now define conntrack extensions of variable size. This
patch is useful to get rid of these unions:
union nf_conntrack_help
union nf_conntrack_proto
union nf_conntrack_nat_help
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
commit a9b3cd7f32 (rcu: convert uses of rcu_assign_pointer(x, NULL) to
RCU_INIT_POINTER) did a lot of incorrect changes, since it did a
complete conversion of rcu_assign_pointer(x, y) to RCU_INIT_POINTER(x,
y).
We miss needed barriers, even on x86, when y is not NULL.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When assigning a NULL value to an RCU protected pointer, no barrier
is needed. The rcu_assign_pointer, used to handle that but will soon
change to not handle the special case.
Convert all rcu_assign_pointer of NULL value.
//smpl
@@ expression P; @@
- rcu_assign_pointer(P, NULL)
+ RCU_INIT_POINTER(P, NULL)
// </smpl>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The rcu callback __nf_ct_ext_free_rcu() just calls a kfree(),
so we use kfree_rcu() instead of the call_rcu(__nf_ct_ext_free_rcu).
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Use RCU helpers to reduce number of sparse warnings
(CONFIG_SPARSE_RCU_POINTER=y), and adds lockdep checks.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
In function update_alloc_size(), sizeof(struct nf_ct_ext) is added twice
wrongly.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
As soon as rcu_read_unlock() is called, there is no guarantee current
thread can safely derefence t pointer, rcu protected.
Fix is to copy t->alloc_size in a temporary variable.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
some users of nf_ct_ext_exist() know ct->ext isn't NULL. For these users, the
check for ct->ext isn't necessary, the function __nf_ct_ext_exist() can be
used instead.
the type of the return value of nf_ct_ext_exist() is changed to bool.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
call_rcu() will unconditionally reinitialize RCU head anyway.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
RCU barriers, rcu_barrier(), is inserted two places.
In nf_conntrack_expect.c nf_conntrack_expect_fini() before the
kmem_cache_destroy(). Firstly to make sure the callback to the
nf_ct_expect_free_rcu() code is still around. Secondly because I'm
unsure about the consequence of having in flight
nf_ct_expect_free_rcu/kmem_cache_free() calls while doing a
kmem_cache_destroy() slab destroy.
And in nf_conntrack_extend.c nf_ct_extend_unregister(), inorder to
wait for completion of callbacks to __nf_ct_ext_free_rcu(), which is
invoked by __nf_ct_ext_add(). It might be more efficient to call
rcu_barrier() in nf_conntrack_core.c nf_conntrack_cleanup_net(), but
thats make it more difficult to read the code (as the callback code
in located in nf_conntrack_extend.c).
Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: Patrick McHardy <kaber@trash.net>
As Linus points out, "ct->ext" and "new" are always equal, avoid unnecessary
dereferences and use "new" directly.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
As suggested by Patrick McHardy, introduce a __krealloc() that doesn't
free the original buffer to fix a double-free and use-after-free bug
introduced by me in netfilter that uses RCU.
Reported-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Tested-by: Dieter Ries <clip2@gmx.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix three ct_extend/NAT extension related races:
- When cleaning up the extension area and removing it from the bysource hash,
the nat->ct pointer must not be set to NULL since it may still be used in
a RCU read side
- When replacing a NAT extension area in the bysource hash, the nat->ct
pointer must be assigned before performing the replacement
- When reallocating extension storage in ct_extend, the old memory must
not be freed immediately since it may still be used by a RCU read side
Possibly fixes https://bugzilla.redhat.com/show_bug.cgi?id=449315
and/or http://bugzilla.kernel.org/show_bug.cgi?id=10875
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The ksize() API is going away because it is being abused and it doesn't even
work consistenly across different allocators. Therefore, convert
net/netfilter/nf_conntrack_extend.c to use krealloc().
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
New extensions may only be added to unconfirmed conntracks to avoid races
when reallocating the storage.
Also change NF_CT_ASSERT to use WARN_ON to get backtraces.
Signed-off-by: Patrick McHardy <kaber@trash.net>
There's a horrible slab abuse in net/netfilter/nf_conntrack_extend.c
that can be replaced with a call to ksize().
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The ->move operation has two bugs:
- It is called with the same extension as source and destination,
so it doesn't update the new extension.
- The address of the old extension is calculated incorrectly,
instead of (void *)ct->ext + ct->ext->offset[i] it uses
ct->ext + ct->ext->offset[i].
Fixes a crash on x86_64 reported by Chuck Ebbert <cebbert@redhat.com>
and Thomas Woerner <twoerner@redhat.com>.
Tested-by: Thomas Woerner <twoerner@redhat.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reported by Chuck Ebbert as:
https://bugzilla.redhat.com/show_bug.cgi?id=259501#c14
This routine is called each time hash should be replaced, nf_conn has
extension list which contains pointers to connection tracking users
(like nat, which is right now the only such user), so when replace takes
place it should copy own extensions. Loop above checks for own
extension, but tries to move higer-layer one, which can lead to above
oops.
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Old space allocator of conntrack had problems about extensibility.
- It required slab cache per combination of extensions.
- It expected what extensions would be assigned, but it was impossible
to expect that completely, then we allocated bigger memory object than
really required.
- It needed to search helper twice due to lock issue.
Now basic informations of a connection are stored in 'struct nf_conn'.
And a storage for extension (helper, NAT) is allocated by kmalloc.
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso