linux.git/net/ipv4/netfilter, branch v2.6.23

[NETFILTER]: Fix/improve deadlock condition on module removal netfilter

2007-09-11T09:28:26+00:00

So I've had a deadlock reported to me.  I've found that the sequence of
events goes like this:

1) process A (modprobe) runs to remove ip_tables.ko

2) process B (iptables-restore) runs and calls setsockopt on a netfilter socket,
increasing the ip_tables socket_ops use count

3) process A acquires a file lock on the file ip_tables.ko, calls remove_module
in the kernel, which in turn executes the ip_tables module cleanup routine,
which calls nf_unregister_sockopt

4) nf_unregister_sockopt, seeing that the use count is non-zero, puts the
calling process into uninterruptible sleep, expecting the process using the
socket option code to wake it up when it exits the kernel

4) the user of the socket option code (process B) in do_ipt_get_ctl, calls
ipt_find_table_lock, which in this case calls request_module to load
ip_tables_nat.ko

5) request_module forks a copy of modprobe (process C) to load the module and
blocks until modprobe exits.

6) Process C. forked by request_module process the dependencies of
ip_tables_nat.ko, of which ip_tables.ko is one.

7) Process C attempts to lock the request module and all its dependencies, it
blocks when it attempts to lock ip_tables.ko (which was previously locked in
step 3)

Theres not really any great permanent solution to this that I can see, but I've
developed a two part solution that corrects the problem

Part 1) Modifies the nf_sockopt registration code so that, instead of using a
use counter internal to the nf_sockopt_ops structure, we instead use a pointer
to the registering modules owner to do module reference counting when nf_sockopt
calls a modules set/get routine.  This prevents the deadlock by preventing set 4
from happening.

Part 2) Enhances the modprobe utilty so that by default it preforms non-blocking
remove operations (the same way rmmod does), and add an option to explicity
request blocking operation.  So if you select blocking operation in modprobe you
can still cause the above deadlock, but only if you explicity try (and since
root can do any old stupid thing it would like....  :)  ).

Signed-off-by: Neil Horman 
Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

[NETFILTER]: nf_conntrack_ipv4: fix "Frag of proto ..." messages

2007-09-11T09:27:01+00:00

Since we're now using a generic tuple decoding function in ICMP
connection tracking, ipv4_get_l4proto() might get called with a
fragmented packet from within an ICMP error. Remove the error
message we used to print when this happens.

Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

[NETFILTER]: nf_nat_sip: don't drop short packets

2007-08-14T20:14:58+00:00

Don't drop packets shorter than "SIP/2.0", just ignore them. Keep-alives
can validly be shorter for example.

Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

[IPV4]: Clean up duplicate includes in net/ipv4/

2007-08-14T05:52:02+00:00

This patch cleans up duplicate includes in
	net/ipv4/

Signed-off-by: Jesper Juhl 
Signed-off-by: Andrew Morton 
Signed-off-by: David S. Miller

[NETFILTER]: nf_nat: add symbolic dependency on IPv4 conntrack

2007-08-08T01:12:01+00:00

Loading nf_nat causes the conntrack core to be loaded, but we need IPv4 as
well.

Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

[NETFILTER]: ipt_recent: avoid a possible NULL pointer deref in recent_seq_open()

2007-08-08T01:10:54+00:00

If the call to seq_open() returns != 0 then the code calls 
kfree(st) but then on the very next line proceeds to 
dereference the pointer - not good.

Problem spotted by the Coverity checker.

Signed-off-by: Jesper Juhl 
Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

[NETFILTER] nf_conntrack_l3proto_ipv4_compat.c: kmalloc + memset conversion to kzalloc

2007-08-03T02:42:24+00:00

Signed-off-by: Mariusz Kozlowski 
Signed-off-by: David S. Miller

netfilter endian regressions

2007-07-26T18:11:56+00:00

no real bugs, just misannotations cropping up

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds

[NETFILTER]: Fix logging regression

2007-07-24T22:29:55+00:00

Loading one of the LOG target fails if a different target has already
registered itself as backend for the same family. This can affect the
ipt_LOG and ipt_ULOG modules when both are loaded.

Reported and tested by: 

Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

some kmalloc/memset ->kzalloc (tree wide)

2007-07-19T17:04:50+00:00

Transform some calls to kmalloc/memset to a single kzalloc (or kcalloc).

Here is a short excerpt of the semantic patch performing
this transformation:

@@
type T2;
expression x;
identifier f,fld;
expression E;
expression E1,E2;
expression e1,e2,e3,y;
statement S;
@@

 x =
- kmalloc
+ kzalloc
  (E1,E2)
  ...  when != \(x->fld=E;\|y=f(...,x,...);\|f(...,x,...);\|x=E;\|while(...) S\|for(e1;e2;e3) S\)
- memset((T2)x,0,E1);

@@
expression E1,E2,E3;
@@

- kzalloc(E1 * E2,E3)
+ kcalloc(E1,E2,E3)

[akpm@linux-foundation.org: get kcalloc args the right way around]
Signed-off-by: Yoann Padioleau 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Acked-by: Russell King 
Cc: Bryan Wu 
Acked-by: Jiri Slaby 
Cc: Dave Airlie 
Acked-by: Roland Dreier 
Cc: Jiri Kosina 
Acked-by: Dmitry Torokhov 
Cc: Benjamin Herrenschmidt 
Acked-by: Mauro Carvalho Chehab 
Acked-by: Pierre Ossman 
Cc: Jeff Garzik 
Cc: "David S. Miller" 
Acked-by: Greg KH 
Cc: James Bottomley 
Cc: "Antonino A. Daplas" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds