linux-stable.git/net/ipv6/ip6mr.c, branch linux-5.4.y

ipmr: convert /proc handlers to rcu_read_lock()

2024-12-14T18:44:33+00:00

[ Upstream commit b96ef16d2f837870daaea51c38cd50458b95ad5c ]

We can use standard rcu_read_lock(), to get rid
of last read_lock(&mrt_lock) call points.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Stable-dep-of: fc9c273d6daa ("ipmr: fix tables suspicious RCU usage")
Signed-off-by: Sasha Levin

ip6mr: Fix skb_under_panic in ip6mr_cache_report()

2023-08-11T09:53:57+00:00

[ Upstream commit 30e0191b16e8a58e4620fa3e2839ddc7b9d4281c ]

skbuff: skb_under_panic: text:ffffffff88771f69 len:56 put:-4
 head:ffff88805f86a800 data:ffff887f5f86a850 tail:0x88 end:0x2c0 dev:pim6reg
 ------------[ cut here ]------------
 kernel BUG at net/core/skbuff.c:192!
 invalid opcode: 0000 [#1] PREEMPT SMP KASAN
 CPU: 2 PID: 22968 Comm: kworker/2:11 Not tainted 6.5.0-rc3-00044-g0a8db05b571a #236
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
 Workqueue: ipv6_addrconf addrconf_dad_work
 RIP: 0010:skb_panic+0x152/0x1d0
 Call Trace:
  
  skb_push+0xc4/0xe0
  ip6mr_cache_report+0xd69/0x19b0
  reg_vif_xmit+0x406/0x690
  dev_hard_start_xmit+0x17e/0x6e0
  __dev_queue_xmit+0x2d6a/0x3d20
  vlan_dev_hard_start_xmit+0x3ab/0x5c0
  dev_hard_start_xmit+0x17e/0x6e0
  __dev_queue_xmit+0x2d6a/0x3d20
  neigh_connected_output+0x3ed/0x570
  ip6_finish_output2+0x5b5/0x1950
  ip6_finish_output+0x693/0x11c0
  ip6_output+0x24b/0x880
  NF_HOOK.constprop.0+0xfd/0x530
  ndisc_send_skb+0x9db/0x1400
  ndisc_send_rs+0x12a/0x6c0
  addrconf_dad_completed+0x3c9/0xea0
  addrconf_dad_work+0x849/0x1420
  process_one_work+0xa22/0x16e0
  worker_thread+0x679/0x10c0
  ret_from_fork+0x28/0x60
  ret_from_fork_asm+0x11/0x20

When setup a vlan device on dev pim6reg, DAD ns packet may sent on reg_vif_xmit().
reg_vif_xmit()
    ip6mr_cache_report()
        skb_push(skb, -skb_network_offset(pkt));//skb_network_offset(pkt) is 4
And skb_push declared as:
	void *skb_push(struct sk_buff *skb, unsigned int len);
		skb->data -= len;
		//0xffff88805f86a84c - 0xfffffffc = 0xffff887f5f86a850
skb->data is set to 0xffff887f5f86a850, which is invalid mem addr, lead to skb_push() fails.

Fixes: 14fb64e1f449 ("[IPV6] MROUTE: Support PIM-SM (SSM).")
Signed-off-by: Yue Haibing 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ipv6: make mc_forwarding atomic

2022-04-15T12:18:32+00:00

[ Upstream commit 145c7a793838add5e004e7d49a67654dc7eba147 ]

This fixes minor data-races in ip6_mc_input() and
batadv_mcast_mla_rtr_flags_softif_get_ipv6()

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ipmr,ip6mr: acquire RTNL before calling ip[6]mr_free_table() on failure path

2022-02-16T11:52:51+00:00

[ Upstream commit 5611a00697c8ecc5aad04392bea629e9d6a20463 ]

ip[6]mr_free_table() can only be called under RTNL lock.

RTNL: assertion failed at net/core/dev.c (10367)
WARNING: CPU: 1 PID: 5890 at net/core/dev.c:10367 unregister_netdevice_many+0x1246/0x1850 net/core/dev.c:10367
Modules linked in:
CPU: 1 PID: 5890 Comm: syz-executor.2 Not tainted 5.16.0-syzkaller-11627-g422ee58dc0ef #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:unregister_netdevice_many+0x1246/0x1850 net/core/dev.c:10367
Code: 0f 85 9b ee ff ff e8 69 07 4b fa ba 7f 28 00 00 48 c7 c6 00 90 ae 8a 48 c7 c7 40 90 ae 8a c6 05 6d b1 51 06 01 e8 8c 90 d8 01 <0f> 0b e9 70 ee ff ff e8 3e 07 4b fa 4c 89 e7 e8 86 2a 59 fa e9 ee
RSP: 0018:ffffc900046ff6e0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888050f51d00 RSI: ffffffff815fa008 RDI: fffff520008dfece
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815f3d6e R11: 0000000000000000 R12: 00000000fffffff4
R13: dffffc0000000000 R14: ffffc900046ff750 R15: ffff88807b7dc000
FS:  00007f4ab736e700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fee0b4f8990 CR3: 000000001e7d2000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 
 mroute_clean_tables+0x244/0xb40 net/ipv6/ip6mr.c:1509
 ip6mr_free_table net/ipv6/ip6mr.c:389 [inline]
 ip6mr_rules_init net/ipv6/ip6mr.c:246 [inline]
 ip6mr_net_init net/ipv6/ip6mr.c:1306 [inline]
 ip6mr_net_init+0x3f0/0x4e0 net/ipv6/ip6mr.c:1298
 ops_init+0xaf/0x470 net/core/net_namespace.c:140
 setup_net+0x54f/0xbb0 net/core/net_namespace.c:331
 copy_net_ns+0x318/0x760 net/core/net_namespace.c:475
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178
 copy_process+0x2e0c/0x7300 kernel/fork.c:2167
 kernel_clone+0xe7/0xab0 kernel/fork.c:2555
 __do_sys_clone+0xc8/0x110 kernel/fork.c:2672
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f4ab89f9059
Code: Unable to access opcode bytes at RIP 0x7f4ab89f902f.
RSP: 002b:00007f4ab736e118 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f4ab8b0bf60 RCX: 00007f4ab89f9059
RDX: 0000000020000280 RSI: 0000000020000270 RDI: 0000000040200000
RBP: 00007f4ab8a5308d R08: 0000000020000300 R09: 0000000020000300
R10: 00000000200002c0 R11: 0000000000000206 R12: 0000000000000000
R13: 00007ffc3977cc1f R14: 00007f4ab736e300 R15: 0000000000022000
 

Fixes: f243e5a7859a ("ipmr,ip6mr: call ip6mr_free_table() on failure path")
Signed-off-by: Eric Dumazet 
Cc: Cong Wang 
Reported-by: syzbot 
Link: https://lore.kernel.org/r/20220208053451.2885398-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net: don't return invalid table id error when we fall back to PF_UNSPEC

2020-06-03T06:20:41+00:00

[ Upstream commit 41b4bd986f86331efc599b9a3f5fb86ad92e9af9 ]

In case we can't find a ->dumpit callback for the requested
(family,type) pair, we fall back to (PF_UNSPEC,type). In effect, we're
in the same situation as if userspace had requested a PF_UNSPEC
dump. For RTM_GETROUTE, that handler is rtnl_dump_all, which calls all
the registered RTM_GETROUTE handlers.

The requested table id may or may not exist for all of those
families. commit ae677bbb4441 ("net: Don't return invalid table id
error when dumping all families") fixed the problem when userspace
explicitly requests a PF_UNSPEC dump, but missed the fallback case.

For example, when we pass ipv6.disable=1 to a kernel with
CONFIG_IP_MROUTE=y and CONFIG_IP_MROUTE_MULTIPLE_TABLES=y,
the (PF_INET6, RTM_GETROUTE) handler isn't registered, so we end up in
rtnl_dump_all, and listing IPv6 routes will unexpectedly print:

# ip -6 r
Error: ipv4: MR table does not exist.
Dump terminated

commit ae677bbb4441 introduced the dump_all_families variable, which
gets set when userspace requests a PF_UNSPEC dump. However, we can't
simply set the family to PF_UNSPEC in rtnetlink_rcv_msg in the
fallback case to get dump_all_families == true, because some messages
types (for example RTM_GETRULE and RTM_GETNEIGH) only register the
PF_UNSPEC handler and use the family to filter in the kernel what is
dumped to userspace. We would then export more entries, that userspace
would have to filter. iproute does that, but other programs may not.

Instead, this patch removes dump_all_families and updates the
RTM_GETROUTE handlers to check if the family that is being dumped is
their own. When it's not, which covers both the intentional PF_UNSPEC
dumps (as dump_all_families did) and the fallback case, ignore the
missing table id error.

Fixes: cb167893f41e ("net: Plumb support for filtering ipv4 and ipv6 multicast route dumps")
Signed-off-by: Sabrina Dubroca
Reviewed-by: David Ahern
Signed-off-by: David S. Miller
Signed-off-by: Greg Kroah-Hartman

ipmr: remove hard code cache_resolve_queue_len limit

2019-09-07T15:49:00+00:00

This is a re-post of previous patch wrote by David Miller[1].

Phil Karn reported[2] that on busy networks with lots of unresolved
multicast routing entries, the creation of new multicast group routes
can be extremely slow and unreliable.

The reason is we hard-coded multicast route entries with unresolved source
addresses(cache_resolve_queue_len) to 10. If some multicast route never
resolves and the unresolved source addresses increased, there will
be no ability to create new multicast route cache.

To resolve this issue, we need either add a sysctl entry to make the
cache_resolve_queue_len configurable, or just remove cache_resolve_queue_len
limit directly, as we already have the socket receive queue limits of mrouted
socket, pointed by David.

>From my side, I'd perfer to remove the cache_resolve_queue_len limit instead
of creating two more(IPv4 and IPv6 version) sysctl entry.

[1] https://lkml.org/lkml/2018/7/22/11
[2] https://lkml.org/lkml/2018/7/21/343

v3: instead of remove cache_resolve_queue_len totally, let's only remove
the hard code limit when allocate the unresolved cache, as Eric Dumazet
suggested, so we don't need to re-count it in other places.

v2: hold the mfc_unres_lock while walking the unresolved list in
queue_count(), as Nikolay Aleksandrov remind.

Reported-by: Phil Karn 
Signed-off-by: Hangbin Liu 
Reviewed-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman

rhashtable: use bit_spin_locks to protect hash bucket.

2019-04-08T02:12:12+00:00

This patch changes rhashtables to use a bit_spin_lock on BIT(1) of the
bucket pointer to lock the hash chain for that bucket.

The benefits of a bit spin_lock are:
 - no need to allocate a separate array of locks.
 - no need to have a configuration option to guide the
   choice of the size of this array
 - locking cost is often a single test-and-set in a cache line
   that will have to be loaded anyway.  When inserting at, or removing
   from, the head of the chain, the unlock is free - writing the new
   address in the bucket head implicitly clears the lock bit.
   For __rhashtable_insert_fast() we ensure this always happens
   when adding a new key.
 - even when lockings costs 2 updates (lock and unlock), they are
   in a cacheline that needs to be read anyway.

The cost of using a bit spin_lock is a little bit of code complexity,
which I think is quite manageable.

Bit spin_locks are sometimes inappropriate because they are not fair -
if multiple CPUs repeatedly contend of the same lock, one CPU can
easily be starved.  This is not a credible situation with rhashtable.
Multiple CPUs may want to repeatedly add or remove objects, but they
will typically do so at different buckets, so they will attempt to
acquire different locks.

As we have more bit-locks than we previously had spinlocks (by at
least a factor of two) we can expect slightly less contention to
go with the slightly better cache behavior and reduced memory
consumption.

To enhance type checking, a new struct is introduced to represent the
  pointer plus lock-bit
that is stored in the bucket-table.  This is "struct rhash_lock_head"
and is empty.  A pointer to this needs to be cast to either an
unsigned lock, or a "struct rhash_head *" to be useful.
Variables of this type are most often called "bkt".

Previously "pprev" would sometimes point to a bucket, and sometimes a
->next pointer in an rhash_head.  As these are now different types,
pprev is NULL when it would have pointed to the bucket. In that case,
'blk' is used, together with correct locking protocol.

Signed-off-by: NeilBrown 
Signed-off-by: David S. Miller

ip6mr: Do not call __IP6_INC_STATS() from preemptible context

2019-03-04T18:55:48+00:00

Similar to commit 44f49dd8b5a6 ("ipmr: fix possible race resulting from
improper usage of IP_INC_STATS_BH() in preemptible context."), we cannot
assume preemption is disabled when incrementing the counter and
accessing a per-CPU variable.

Preemption can be enabled when we add a route in process context that
corresponds to packets stored in the unresolved queue, which are then
forwarded using this route [1].

Fix this by using IP6_INC_STATS() which takes care of disabling
preemption on architectures where it is needed.

[1]
[  157.451447] BUG: using __this_cpu_add() in preemptible [00000000] code: smcrouted/2314
[  157.460409] caller is ip6mr_forward2+0x73e/0x10e0
[  157.460434] CPU: 3 PID: 2314 Comm: smcrouted Not tainted 5.0.0-rc7-custom-03635-g22f2712113f1 #1336
[  157.460449] Hardware name: Mellanox Technologies Ltd. MSN2100-CB2FO/SA001017, BIOS 5.6.5 06/07/2016
[  157.460461] Call Trace:
[  157.460486]  dump_stack+0xf9/0x1be
[  157.460553]  check_preemption_disabled+0x1d6/0x200
[  157.460576]  ip6mr_forward2+0x73e/0x10e0
[  157.460705]  ip6_mr_forward+0x9a0/0x1510
[  157.460771]  ip6mr_mfc_add+0x16b3/0x1e00
[  157.461155]  ip6_mroute_setsockopt+0x3cb/0x13c0
[  157.461384]  do_ipv6_setsockopt.isra.8+0x348/0x4060
[  157.462013]  ipv6_setsockopt+0x90/0x110
[  157.462036]  rawv6_setsockopt+0x4a/0x120
[  157.462058]  __sys_setsockopt+0x16b/0x340
[  157.462198]  __x64_sys_setsockopt+0xbf/0x160
[  157.462220]  do_syscall_64+0x14d/0x610
[  157.462349]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: 0912ea38de61 ("[IPV6] MROUTE: Add stats in multicast routing module method ip6_mr_forward().")
Signed-off-by: Ido Schimmel 
Reported-by: Amit Cohen 
Signed-off-by: David S. Miller

ipmr: ip6mr: Create new sockopt to clear mfc cache or vifs

2019-02-21T21:05:05+00:00

Currently the only way to clear the forwarding cache was to delete the
entries one by one using the MRT_DEL_MFC socket option or to destroy and
recreate the socket.

Create a new socket option which with the use of optional flags can
clear any combination of multicast entries (static or not static) and
multicast vifs (static or not static).

Calling the new socket option MRT_FLUSH with the flags MRT_FLUSH_MFC and
MRT_FLUSH_VIFS will clear all entries and vifs on the socket except for
static entries.

Signed-off-by: Callum Sinclair 
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller