linux-stable.git/net/ipv4/igmp.c, branch linux-3.2.y

net: igmp: add a missing rcu locking section

2018-05-31T23:30:12+00:00

commit e7aadb27a5415e8125834b84a74477bfbee4eff5 upstream.

Newly added igmpv3_get_srcaddr() needs to be called under rcu lock.

Timer callbacks do not ensure this locking.

=============================
WARNING: suspicious RCU usage
4.15.0+ #200 Not tainted
-----------------------------
./include/linux/inetdevice.h:216 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
3 locks held by syzkaller616973/4074:
 #0:  (&mm->mmap_sem){++++}, at: [<00000000bfce669e>] __do_page_fault+0x32d/0xc90 arch/x86/mm/fault.c:1355
 #1:  ((&im->timer)){+.-.}, at: [<00000000619d2f71>] lockdep_copy_map include/linux/lockdep.h:178 [inline]
 #1:  ((&im->timer)){+.-.}, at: [<00000000619d2f71>] call_timer_fn+0x1c6/0x820 kernel/time/timer.c:1316
 #2:  (&(&im->lock)->rlock){+.-.}, at: [<000000005f833c5c>] spin_lock_bh include/linux/spinlock.h:315 [inline]
 #2:  (&(&im->lock)->rlock){+.-.}, at: [<000000005f833c5c>] igmpv3_send_report+0x98/0x5b0 net/ipv4/igmp.c:600

stack backtrace:
CPU: 0 PID: 4074 Comm: syzkaller616973 Not tainted 4.15.0+ #200
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4592
 __in_dev_get_rcu include/linux/inetdevice.h:216 [inline]
 igmpv3_get_srcaddr net/ipv4/igmp.c:329 [inline]
 igmpv3_newpack+0xeef/0x12e0 net/ipv4/igmp.c:389
 add_grhead.isra.27+0x235/0x300 net/ipv4/igmp.c:432
 add_grec+0xbd3/0x1170 net/ipv4/igmp.c:565
 igmpv3_send_report+0xd5/0x5b0 net/ipv4/igmp.c:605
 igmp_send_report+0xc43/0x1050 net/ipv4/igmp.c:722
 igmp_timer_expire+0x322/0x5c0 net/ipv4/igmp.c:831
 call_timer_fn+0x228/0x820 kernel/time/timer.c:1326
 expire_timers kernel/time/timer.c:1363 [inline]
 __run_timers+0x7ee/0xb70 kernel/time/timer.c:1666
 run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692
 __do_softirq+0x2d7/0xb85 kernel/softirq.c:285
 invoke_softirq kernel/softirq.c:365 [inline]
 irq_exit+0x1cc/0x200 kernel/softirq.c:405
 exiting_irq arch/x86/include/asm/apic.h:541 [inline]
 smp_apic_timer_interrupt+0x16b/0x700 arch/x86/kernel/apic/apic.c:1052
 apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:938

Fixes: a46182b00290 ("net: igmp: Use correct source address on IGMPv3 reports")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 

Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: igmp: fix source address check for IGMPv3 reports

2018-03-03T15:51:02+00:00

commit ad23b750933ea7bf962678972a286c78a8fa36aa upstream.

Commit "net: igmp: Use correct source address on IGMPv3 reports"
introduced a check to validate the source address of locally generated
IGMPv3 packets.
Instead of checking the local interface address directly, it uses
inet_ifa_match(fl4->saddr, ifa), which checks if the address is on the
local subnet (or equal to the point-to-point address if used).

This breaks for point-to-point interfaces, so check against
ifa->ifa_local directly.

Cc: Kevin Cernekee 
Fixes: a46182b00290 ("net: igmp: Use correct source address on IGMPv3 reports")
Reported-by: Sebastian Gottschall 
Signed-off-by: Felix Fietkau 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: igmp: Use correct source address on IGMPv3 reports

2018-03-03T15:51:02+00:00

commit a46182b00290839fa3fa159d54fd3237bd8669f0 upstream.

Closing a multicast socket after the final IPv4 address is deleted
from an interface can generate a membership report that uses the
source IP from a different interface.  The following test script, run
from an isolated netns, reproduces the issue:

    #!/bin/bash

    ip link add dummy0 type dummy
    ip link add dummy1 type dummy
    ip link set dummy0 up
    ip link set dummy1 up
    ip addr add 10.1.1.1/24 dev dummy0
    ip addr add 192.168.99.99/24 dev dummy1

    tcpdump -U -i dummy0 &
    socat EXEC:"sleep 2" \
        UDP4-DATAGRAM:239.101.1.68:8889,ip-add-membership=239.0.1.68:10.1.1.1 &

    sleep 1
    ip addr del 10.1.1.1/24 dev dummy0
    sleep 5
    kill %tcpdump

RFC 3376 specifies that the report must be sent with a valid IP source
address from the destination subnet, or from address 0.0.0.0.  Add an
extra check to make sure this is the case.

Signed-off-by: Kevin Cernekee 
Reviewed-by: Andrew Lunn 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

igmp, mld: Fix memory leak in igmpv3/mld_del_delrec()

2017-03-16T02:18:58+00:00

commit 9c8bb163ae784be4f79ae504e78c862806087c54 upstream.

In function igmpv3/mld_add_delrec() we allocate pmc and put it in
idev->mc_tomb, so we should free it when we don't need it in del_delrec().
But I removed kfree(pmc) incorrectly in latest two patches. Now fix it.

Fixes: 24803f38a5c0 ("igmp: do not remove igmp souce list info when ...")
Fixes: 1666d49e1d41 ("mld: do not remove mld souce list info when ...")
Reported-by: Daniel Borkmann 
Signed-off-by: Hangbin Liu 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

igmp: do not remove igmp souce list info when set link down

2017-03-16T02:18:57+00:00

commit 24803f38a5c0b6c57ed800b47e695f9ce474bc3a upstream.

In commit 24cf3af3fed5 ("igmp: call ip_mc_clear_src..."), we forgot to remove
igmpv3_clear_delrec() in ip_mc_down(), which also called ip_mc_clear_src().
This make us clear all IGMPv3 source filter info after NETDEV_DOWN.
Move igmpv3_clear_delrec() to ip_mc_destroy_dev() and then no need
ip_mc_clear_src() in ip_mc_destroy_dev().

On the other hand, we should restore back instead of free all source filter
info in igmpv3_del_delrec(). Or we will not able to restore IGMPv3 source
filter info after NETDEV_UP and NETDEV_POST_TYPE_CHANGE.

Fixes: 24cf3af3fed5 ("igmp: call ip_mc_clear_src() only when ...")
Signed-off-by: Hangbin Liu 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2:
 - Use IGMP_Unsolicited_Report_Count instead of sysctl_igmp_qrv
 - Adjust context]
Signed-off-by: Ben Hutchings

igmp: Make igmp group member RFC 3376 compliant

2017-03-16T02:18:55+00:00

[ Upstream commit 7ababb782690e03b78657e27bd051e20163af2d6 ]

5.2. Action on Reception of a Query

 When a system receives a Query, it does not respond immediately.
 Instead, it delays its response by a random amount of time, bounded
 by the Max Resp Time value derived from the Max Resp Code in the
 received Query message.  A system may receive a variety of Queries on
 different interfaces and of different kinds (e.g., General Queries,
 Group-Specific Queries, and Group-and-Source-Specific Queries), each
 of which may require its own delayed response.

 Before scheduling a response to a Query, the system must first
 consider previously scheduled pending responses and in many cases
 schedule a combined response.  Therefore, the system must be able to
 maintain the following state:

 o A timer per interface for scheduling responses to General Queries.

 o A per-group and interface timer for scheduling responses to Group-
   Specific and Group-and-Source-Specific Queries.

 o A per-group and interface list of sources to be reported in the
   response to a Group-and-Source-Specific Query.

 When a new Query with the Router-Alert option arrives on an
 interface, provided the system has state to report, a delay for a
 response is randomly selected in the range (0, [Max Resp Time]) where
 Max Resp Time is derived from Max Resp Code in the received Query
 message.  The following rules are then used to determine if a Report
 needs to be scheduled and the type of Report to schedule.  The rules
 are considered in order and only the first matching rule is applied.

 1. If there is a pending response to a previous General Query
    scheduled sooner than the selected delay, no additional response
    needs to be scheduled.

 2. If the received Query is a General Query, the interface timer is
    used to schedule a response to the General Query after the
    selected delay.  Any previously pending response to a General
    Query is canceled.
--8<--

Currently the timer is rearmed with new random expiration time for
every incoming query regardless of possibly already pending report.
Which is not aligned with the above RFE.
It also might happen that higher rate of incoming queries can
postpone the report after the expiration time of the first query
causing group membership loss.

Now the per interface general query timer is rearmed only
when there is no pending report already scheduled on that interface or
the newly selected expiration time is before the already pending
scheduled report.

Signed-off-by: Michal Tesar 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

mld, igmp: Fix reserved tailroom calculation

2016-04-01T00:54:37+00:00

commit 1837b2e2bcd23137766555a63867e649c0b637f0 upstream.

The current reserved_tailroom calculation fails to take hlen and tlen into
account.

skb:
[__hlen__|__data____________|__tlen___|__extra__]
^                                               ^
head                                            skb_end_offset

In this representation, hlen + data + tlen is the size passed to alloc_skb.
"extra" is the extra space made available in __alloc_skb because of
rounding up by kmalloc. We can reorder the representation like so:

[__hlen__|__data____________|__extra__|__tlen___]
^                                               ^
head                                            skb_end_offset

The maximum space available for ip headers and payload without
fragmentation is min(mtu, data + extra). Therefore,
reserved_tailroom
= data + extra + tlen - min(mtu, data + extra)
= skb_end_offset - hlen - min(mtu, skb_end_offset - hlen - tlen)
= skb_tailroom - min(mtu, skb_tailroom - tlen) ; after skb_reserve(hlen)

Compare the second line to the current expression:
reserved_tailroom = skb_end_offset - min(mtu, skb_end_offset)
and we can see that hlen and tlen are not taken into account.

The min() in the third line can be expanded into:
if mtu < skb_tailroom - tlen:
	reserved_tailroom = skb_tailroom - mtu
else:
	reserved_tailroom = tlen

Depending on hlen, tlen, mtu and the number of multicast address records,
the current code may output skbs that have less tailroom than
dev->needed_tailroom or it may output more skbs than needed because not all
space available is used.

Fixes: 4c672e4b ("ipv6: mld: fix add_grhead skb_over_panic for devs with large MTUs")
Signed-off-by: Benjamin Poirier 
Acked-by: Hannes Frederic Sowa 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

ipv4: igmp: Allow removing groups from a removed interface

2015-12-30T02:25:59+00:00

commit 4eba7bb1d72d9bde67d810d09bf62dc207b63c5c upstream.

When a multicast group is joined on a socket, a struct ip_mc_socklist
is appended to the sockets mc_list containing information about the
joined group.

If the interface is hot unplugged, this entry becomes stale. Prior to
commit 52ad353a5344f ("igmp: fix the problem when mc leave group") it
was possible to remove the stale entry by performing a
IP_DROP_MEMBERSHIP, passing either the old ifindex or ip address on
the interface. However, this fix enforces that the interface must
still exist. Thus with time, the number of stale entries grows, until
sysctl_igmp_max_memberships is reached and then it is not possible to
join and more groups.

The previous patch fixes an issue where a IP_DROP_MEMBERSHIP is
performed without specifying the interface, either by ifindex or ip
address. However here we do supply one of these. So loosen the
restriction on device existence to only apply when the interface has
not been specified. This then restores the ability to clean up the
stale entries.

Signed-off-by: Andrew Lunn 
Fixes: 52ad353a5344f "(igmp: fix the problem when mc leave group")
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

ipv6: mld: fix add_grhead skb_over_panic for devs with large MTUs

2015-02-20T00:49:24+00:00

commit 4c672e4b42bc8046d63a6eb0a2c6a450a501af32 upstream.

It has been reported that generating an MLD listener report on
devices with large MTUs (e.g. 9000) and a high number of IPv6
addresses can trigger a skb_over_panic():

skbuff: skb_over_panic: text:ffffffff80612a5d len:3776 put:20
head:ffff88046d751000 data:ffff88046d751010 tail:0xed0 end:0xec0
dev:port1
 ------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:100!
invalid opcode: 0000 [#1] SMP
Modules linked in: ixgbe(O)
CPU: 3 PID: 0 Comm: swapper/3 Tainted: G O 3.14.23+ #4
[...]
Call Trace:
 
 [] ? skb_put+0x3a/0x3b
 [] ? add_grhead+0x45/0x8e
 [] ? add_grec+0x394/0x3d4
 [] ? mld_ifc_timer_expire+0x195/0x20d
 [] ? mld_dad_timer_expire+0x45/0x45
 [] ? call_timer_fn.isra.29+0x12/0x68
 [] ? run_timer_softirq+0x163/0x182
 [] ? __do_softirq+0xe0/0x21d
 [] ? irq_exit+0x4e/0xd3
 [] ? smp_apic_timer_interrupt+0x3b/0x46
 [] ? apic_timer_interrupt+0x6a/0x70

mld_newpack() skb allocations are usually requested with dev->mtu
in size, since commit 72e09ad107e7 ("ipv6: avoid high order allocations")
we have changed the limit in order to be less likely to fail.

However, in MLD/IGMP code, we have some rather ugly AVAILABLE(skb)
macros, which determine if we may end up doing an skb_put() for
adding another record. To avoid possible fragmentation, we check
the skb's tailroom as skb->dev->mtu - skb->len, which is a wrong
assumption as the actual max allocation size can be much smaller.

The IGMP case doesn't have this issue as commit 57e1ab6eaddc
("igmp: refine skb allocations") stores the allocation size in
the cb[].

Set a reserved_tailroom to make it fit into the MTU and use
skb_availroom() helper instead. This also allows to get rid of
igmp_skb_size().

Reported-by: Wei Liu 
Fixes: 72e09ad107e7 ("ipv6: avoid high order allocations")
Signed-off-by: Daniel Borkmann 
Cc: Eric Dumazet 
Cc: Hannes Frederic Sowa 
Cc: David L Stevens 
Acked-by: Eric Dumazet 
Acked-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

ipv4: Remove all uses of LL_ALLOCATED_SPACE

2015-02-20T00:49:23+00:00

commit 660882432909dbe611f1792eda158188065cb9f1 upstream.

ipv4: Remove all uses of LL_ALLOCATED_SPACE

The macro LL_ALLOCATED_SPACE was ill-conceived.  It applies the
alignment to the sum of needed_headroom and needed_tailroom.  As
the amount that is then reserved for head room is needed_headroom
with alignment, this means that the tail room left may be too small.

This patch replaces all uses of LL_ALLOCATED_SPACE in net/ipv4
with the macro LL_RESERVED_SPACE and direct reference to
needed_tailroom.

This also fixes the problem with needed_headroom changing between
allocating the skb and reserving the head room.

Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings