Since 49ffcf8f99 ("sysctl: update
sysctl_check_table") setting struct ctl_table.procname = NULL does no
longer work as it used to the way the AX.25 code is expecting it to
resulting in the AX.25 sysctl registration code to break if
CONFIG_AX25_DAMA_SLAVE was not set as in some distribution kernels.
Kernel releases from 2.6.24 are affected.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Without CONFIG_NET_NS, namespace is always &init_net.
Compiler will be able to omit namespace comparisons with this patch.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tihomir Heidelberg - 9a4gl, reports:
--------------------
I would like to direct you attention to one problem existing in ax.25
kernel since 2.4. If listening socket is closed and its SKB queue is
released but those sockets get weird. Those "unAccepted()" sockets
should be destroyed in ax25_std_heartbeat_expiry, but it will not
happen. And there is also a note about that in ax25_std_timer.c:
/* Magic here: If we listen() and a new link dies before it
is accepted() it isn't 'dead' so doesn't get removed. */
This issue cause ax25d to stop accepting new connections and I had to
restarted ax25d approximately each day and my services were unavailable.
Also netstat -n -l shows invalid source and device for those listening
sockets. It is strange why ax25d's listening socket get weird because of
this issue, but definitely when I solved this bug I do not have problems
with ax25d anymore and my ax25d can run for months without problems.
--------------------
Actually as far as I can see, this problem is even in releases
as far back as 2.2.x as well.
It seems senseless to special case this test on TCP_LISTEN state.
Anything still stuck in state 0 has no external references and
we can just simply kill it off directly.
Signed-off-by: David S. Miller <davem@davemloft.net>
The way that listening sockets work in ax25 is that the packet input
code path creates new socks via ax25_make_new() and attaches them
to the incoming SKB. This SKB gets queued up into the listening
socket's receive queue.
When accept()'d the sock gets hooked up to the real parent socket.
Alternatively, if the listening socket is closed and released, any
unborn socks stuff up in the receive queue get released.
So during this time period these sockets are unreachable in any
other way, so no wakeup events nor references to their ->sk_socket
and ->sk_sleep members can occur. And even if they do, all such
paths have to make NULL checks.
So do not deceptively initialize them in ax25_make_new() to the
values in the listening socket. Leave them at NULL.
Finally, use sock_graft() in ax25_accept().
Signed-off-by: David S. Miller <davem@davemloft.net>
From: Jarek Poplawski <jarkao2@gmail.com>
There is only one function in AX25 calling skb_append(), and it really
looks suspicious: appends skb after previously enqueued one, but in
the meantime this previous skb could be removed from the queue.
This patch Fixes it the simple way, so this is not fully compatible with
the current method, but testing hasn't shown any problems.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The ax25_uid_free call walks the ax25_uid_list and releases entries
from it. The problem is that after the fisrt call to hlist_del_init
the hlist_for_each_entry (which hides behind the ax25_uid_for_each)
will consider the current position to be the last and will return.
Thus, the whole list will be left not freed.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Given that there are no apparent calls to lock_kernel() or
unlock_kernel() under net/ax25, delete the TODO reference related to
that.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce per-sock inlines: sock_net(), sock_net_set()
and per-inet_timewait_sock inlines: twsk_net(), twsk_net_set().
Without CONFIG_NET_NS, no namespace other than &init_net exists.
Let's explicitly define them to help compiler optimizations.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Introduce per-net_device inlines: dev_net(), dev_net_set().
Without CONFIG_NET_NS, no namespace other than &init_net exists.
Let's explicitly define them to help compiler optimizations.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
According to some OOPS reports ax25_kick tries to clone NULL skbs
sometimes. It looks like a race with ax25_clear_queues(). Probably
there is no need to add more than a simple check for this yet.
Another report suggested there are probably also cases where ax25
->paclen == 0 can happen in ax25_output(); this wasn't confirmed
during testing but let's leave this debugging check for some time.
Reported-and-tested-by: Jann Traschewski <jann@gmx.de>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch changes current use of: init_timer(), add_timer()
and del_timer() to setup_timer() with mod_timer(), which
should be safer anyway.
Reported-by: Jann Traschewski <jann@gmx.de>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
According to one of Jann's OOPS reports it looks like
BUG_ON(timer_pending(timer)) triggers during add_timer()
in ax25_start_t1timer(). This patch changes current use
of: init_timer(), add_timer() and del_timer() to
setup_timer() with mod_timer(), which should be safer
anyway.
Reported-by: Jann Traschewski <jann@gmx.de>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
> =================================
> [ INFO: inconsistent lock state ]
> 2.6.24-dg8ngn-p02 #1
> ---------------------------------
> inconsistent {softirq-on-W} -> {in-softirq-R} usage.
> linuxnet/3046 [HC0[0]:SC1[2]:HE1:SE0] takes:
> (ax25_route_lock){--.+}, at: [<f8a0cfb7>] ax25_get_route+0x18/0xb7 [ax25]
> {softirq-on-W} state was registered at:
...
This lockdep report shows that ax25_route_lock is taken for reading in
softirq context, and for writing in process context with BHs enabled.
So, to make this safe, all write_locks in ax25_route.c are changed to
_bh versions.
Reported-by: Jann Traschewski <jann@gmx.de>,
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This lockdep warning:
> =======================================================
> [ INFO: possible circular locking dependency detected ]
> 2.6.24 #3
> -------------------------------------------------------
> swapper/0 is trying to acquire lock:
> (ax25_list_lock){-+..}, at: [<f91dd3b1>] ax25_destroy_socket+0x171/0x1f0 [ax25]
>
> but task is already holding lock:
> (slock-AF_AX25){-+..}, at: [<f91dbabc>] ax25_std_heartbeat_expiry+0x1c/0xe0 [ax25]
>
> which lock already depends on the new lock.
...
shows that ax25_list_lock and slock-AF_AX25 are taken in different
order: ax25_info_show() takes slock (bh_lock_sock(ax25->sk)) while
ax25_list_lock is held, so reversely to other functions. To fix this
the sock lock should be moved to ax25_info_start(), and there would
be still problem with breaking ax25_list_lock (it seems this "proper"
order isn't optimal yet). But, since it's only for reading proc info
it seems this is not necessary (e.g. ax25_send_to_raw() does similar
reading without this lock too).
So, this patch removes sock lock to avoid deadlock possibility; there
is also used sock_i_ino() function, which reads sk_socket under proper
read lock. Additionally printf format of this i_ino is changed to %lu.
Reported-by: Bernard Pidoux F6BVP <f6bvp@free.fr>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
on the last run overlooked that sfuzz triggable message.
move the message to the corresponding comment.
Signed-off-by: maximilian attems <max@stro.at>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ax25/ax25_route.c:251:13: warning: context imbalance in
'ax25_rt_seq_start' - wrong count at exit
net/ax25/ax25_route.c:276:13: warning: context imbalance in 'ax25_rt_seq_stop'
- unexpected unlock
net/ax25/ax25_std_timer.c:65:25: warning: expensive signed divide
net/ax25/ax25_uid.c:46:1: warning: symbol 'ax25_uid_list' was not declared.
Should it be static?
net/ax25/ax25_uid.c:146:13: warning: context imbalance in 'ax25_uid_seq_start'
- wrong count at exit
net/ax25/ax25_uid.c:169:13: warning: context imbalance in 'ax25_uid_seq_stop'
- unexpected unlock
net/ax25/af_ax25.c:573:28: warning: expensive signed divide
net/ax25/af_ax25.c:1865:13: warning: context imbalance in 'ax25_info_start' -
wrong count at exit
net/ax25/af_ax25.c:1888:13: warning: context imbalance in 'ax25_info_stop' -
unexpected unlock
net/ax25/ax25_ds_timer.c:133:25: warning: expensive signed divide
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This one is almost the same as the hunks in the
first patch, but ax25 tables are created dynamically.
So this patch differs a bit to handle this case.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Many-many code in the kernel initialized the timer->function
and timer->data together with calling init_timer(timer). There
is already a helper for this. Use it for networking code.
The patch is HUGE, but makes the code 130 lines shorter
(98 insertions(+), 228 deletions(-)).
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Bernard Pidoux F6BVP reported:
> When I killall kissattach I can see the following message.
>
> This happens on kernel 2.6.24-rc5 already patched with the 6 previously
> patches I sent recently.
>
>
> =======================================================
> [ INFO: possible circular locking dependency detected ]
> 2.6.23.9 #1
> -------------------------------------------------------
> kissattach/2906 is trying to acquire lock:
> (linkfail_lock){-+..}, at: [<d8bd4603>] ax25_link_failed+0x11/0x39 [ax25]
>
> but task is already holding lock:
> (ax25_list_lock){-+..}, at: [<d8bd7c7c>] ax25_device_event+0x38/0x84
> [ax25]
>
> which lock already depends on the new lock.
>
>
> the existing dependency chain (in reverse order) is:
...
lockdep is worried about the different order here:
#1 (rose_neigh_list_lock){-+..}:
#3 (ax25_list_lock){-+..}:
#0 (linkfail_lock){-+..}:
#1 (rose_neigh_list_lock){-+..}:
#3 (ax25_list_lock){-+..}:
#0 (linkfail_lock){-+..}:
So, ax25_list_lock could be taken before and after linkfail_lock.
I don't know if this three-thread clutch is very probable (or
possible at all), but it seems another bug reported by Bernard
("[...] system impossible to reboot with linux-2.6.24-rc5")
could have similar source - namely ax25_list_lock held by
ax25_kill_by_device() during ax25_disconnect(). It looks like the
only place which calls ax25_disconnect() this way, so I guess, it
isn't necessary.
This patch is breaking the lock for ax25_disconnect().
Reported-and-tested-by: Bernard Pidoux <f6bvp@free.fr>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sfuzz can easily trigger any of those.
move the printk message to the corresponding comment: makes the
intention of the code clear and easy to pick up on an scheduled
removal. as bonus simplify the braces placement.
Signed-off-by: maximilian attems <max@stro.at>
Signed-off-by: David S. Miller <davem@davemloft.net>
This operation helper abstracts:
skb->mac_header = skb->data;
but it was done in two more places which were actually:
skb->mac_header = skb->network_header;
and those are corrected here.
Signed-off-by: David S. Miller <davem@davemloft.net>
Bernard Pidoux reported these lockdep warnings:
[ INFO: possible irq lock inversion dependency detected ]
2.6.23.1 #1
---------------------------------------------------------
fpac/4933 just changed the state of lock:
(slock-AF_AX25){--..}, at: [<d8be3312>] ax25_disconnect+0x46/0xaf
[ax25]
but this lock was taken by another, soft-irq-safe lock in the past:
(ax25_list_lock){-+..}
and interrupts could create inverse lock ordering between them.
[...]
[ INFO: inconsistent lock state ]
2.6.23.1 #1
---------------------------------
inconsistent {in-softirq-W} -> {softirq-on-W} usage.
ax25_call/4005 [HC0[0]:SC0[0]:HE1:SE1] takes:
(slock-AF_AX25){-+..}, at: [<d8b79312>] ax25_disconnect+0x46/0xaf [ax25]
[...]
This means slock-AF_AX25 could be taken both from softirq and process
context with softirqs enabled, so it's endangered itself, but also makes
ax25_list_lock vulnerable. It was not 100% verified if the real lockup
can happen, but this fix isn't very costly and looks safe anyway.
(It was tested by Bernard with 2.6.23.9 and 2.6.24-rc5 kernels.)
Reported_by: Bernard Pidoux <pidoux@ccr.jussieu.fr>
Tested_by: Bernard Pidoux <pidoux@ccr.jussieu.fr>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Finally, the zero_it argument can be completely removed from
the callers and from the function prototype.
Besides, fix the checkpatch.pl warnings about using the
assignments inside if-s.
This patch is rather big, and it is a part of the previous one.
I splitted it wishing to make the patches more readable. Hope
this particular split helped.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
