linux-stable.git/include/net, branch v3.16.67

ipv4: fix a race in update_or_create_fnhe()

2019-05-11T14:22:48+00:00

commit caa415270c732505240bb60171c44a7838c555e8 upstream.

nh_exceptions is effectively used under rcu, but lacks proper
barriers. Between kzalloc() and setting of nh->nh_exceptions(),
we need a proper memory barrier.

Signed-off-by: Eric Dumazet 
Fixes: 4895c771c7f00 ("ipv4: Add FIB nexthop exceptions.")
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

cipso: don't use IPCB() to locate the CIPSO IP option

2019-02-11T17:53:21+00:00

commit 04f81f0154e4bf002be6f4d85668ce1257efa4d9 upstream.

Using the IPCB() macro to get the IPv4 options is convenient, but
unfortunately NetLabel often needs to examine the CIPSO option outside
of the scope of the IP layer in the stack.  While historically IPCB()
worked above the IP layer, due to the inclusion of the inet_skb_param
struct at the head of the {tcp,udp}_skb_cb structs, recent commit
971f10ec ("tcp: better TCP_SKB_CB layout to reduce cache line misses")
reordered the tcp_skb_cb struct and invalidated this IPCB() trick.

This patch fixes the problem by creating a new function,
cipso_v4_optptr(), which locates the CIPSO option inside the IP header
without calling IPCB().  Unfortunately, this isn't as fast as a simple
lookup so some additional tweaks were made to limit the use of this
new function.

Reported-by: Casey Schaufler 
Signed-off-by: Paul Moore 
Tested-by: Casey Schaufler 
Signed-off-by: Ben Hutchings

net: ipv4: update fnhe_pmtu when first hop's MTU changes

2018-12-16T22:09:40+00:00

commit af7d6cce53694a88d6a1bb60c9a239a6a5144459 upstream.

Since commit 5aad1de5ea2c ("ipv4: use separate genid for next hop
exceptions"), exceptions get deprecated separately from cached
routes. In particular, administrative changes don't clear PMTU anymore.

As Stefano described in commit e9fa1495d738 ("ipv6: Reflect MTU changes
on PMTU of exceptions for MTU-less routes"), the PMTU discovered before
the local MTU change can become stale:
 - if the local MTU is now lower than the PMTU, that PMTU is now
   incorrect
 - if the local MTU was the lowest value in the path, and is increased,
   we might discover a higher PMTU

Similarly to what commit e9fa1495d738 did for IPv6, update PMTU in those
cases.

If the exception was locked, the discovered PMTU was smaller than the
minimal accepted PMTU. In that case, if the new local MTU is smaller
than the current PMTU, let PMTU discovery figure out if locking of the
exception is still needed.

To do this, we need to know the old link MTU in the NETDEV_CHANGEMTU
notifier. By the time the notifier is called, dev->mtu has been
changed. This patch adds the old MTU as additional information in the
notifier structure, and a new call_netdevice_notifiers_u32() function.

Fixes: 5aad1de5ea2c ("ipv4: use separate genid for next hop exceptions")
Signed-off-by: Sabrina Dubroca 
Reviewed-by: Stefano Brivio 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16:
 - Pass net_device argument to call_netdevice_notifiers_info()
 - Adjust context]
Signed-off-by: Ben Hutchings

netfilter: nft_set: fix allocation size overflow in privsize callback.

2018-12-16T22:08:48+00:00

commit 4ef360dd6a65f6ef337645e1b65e744034754b19 upstream.

In order to determine allocation size of set, ->privsize is invoked.
At this point, both desc->size and size of each data structure of set
are used. desc->size means number of element that is given by user.
desc->size is u32 type. so that upperlimit of set element is 4294967295.
but return type of ->privsize is also u32. hence overflow can occurred.

test commands:
   %nft add table ip filter
   %nft add set ip filter hash1 { type ipv4_addr \; size 4294967295 \; }
   %nft list ruleset

splat looks like:
[ 1239.202910] kasan: CONFIG_KASAN_INLINE enabled
[ 1239.208788] kasan: GPF could be caused by NULL-ptr deref or user memory access
[ 1239.217625] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 1239.219329] CPU: 0 PID: 1603 Comm: nft Not tainted 4.18.0-rc5+ #7
[ 1239.229091] RIP: 0010:nft_hash_walk+0x1d2/0x310 [nf_tables_set]
[ 1239.229091] Code: 84 d2 7f 10 4c 89 e7 89 44 24 38 e8 d8 5a 17 e0 8b 44 24 38 48 8d 7b 10 41 0f b6 0c 24 48 89 fa 48 89 fe 48 c1 ea 03 83 e6 07 <42> 0f b6 14 3a 40 38 f2 7f 1a 84 d2 74 16
[ 1239.229091] RSP: 0018:ffff8801118cf358 EFLAGS: 00010246
[ 1239.229091] RAX: 0000000000000000 RBX: 0000000000020400 RCX: 0000000000000001
[ 1239.229091] RDX: 0000000000004082 RSI: 0000000000000000 RDI: 0000000000020410
[ 1239.229091] RBP: ffff880114d5a988 R08: 0000000000007e94 R09: ffff880114dd8030
[ 1239.229091] R10: ffff880114d5a988 R11: ffffed00229bb006 R12: ffff8801118cf4d0
[ 1239.229091] R13: ffff8801118cf4d8 R14: 0000000000000000 R15: dffffc0000000000
[ 1239.229091] FS:  00007f5a8fe0b700(0000) GS:ffff88011b600000(0000) knlGS:0000000000000000
[ 1239.229091] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1239.229091] CR2: 00007f5a8ecc27b0 CR3: 000000010608e000 CR4: 00000000001006f0
[ 1239.229091] Call Trace:
[ 1239.229091]  ? nft_hash_remove+0xf0/0xf0 [nf_tables_set]
[ 1239.229091]  ? memset+0x1f/0x40
[ 1239.229091]  ? __nla_reserve+0x9f/0xb0
[ 1239.229091]  ? memcpy+0x34/0x50
[ 1239.229091]  nf_tables_dump_set+0x9a1/0xda0 [nf_tables]
[ 1239.229091]  ? __kmalloc_reserve.isra.29+0x2e/0xa0
[ 1239.229091]  ? nft_chain_hash_obj+0x630/0x630 [nf_tables]
[ 1239.229091]  ? nf_tables_commit+0x2c60/0x2c60 [nf_tables]
[ 1239.229091]  netlink_dump+0x470/0xa20
[ 1239.229091]  __netlink_dump_start+0x5ae/0x690
[ 1239.229091]  nft_netlink_dump_start_rcu+0xd1/0x160 [nf_tables]
[ 1239.229091]  nf_tables_getsetelem+0x2e5/0x4b0 [nf_tables]
[ 1239.229091]  ? nft_get_set_elem+0x440/0x440 [nf_tables]
[ 1239.229091]  ? nft_chain_hash_obj+0x630/0x630 [nf_tables]
[ 1239.229091]  ? nf_tables_dump_obj_done+0x70/0x70 [nf_tables]
[ 1239.229091]  ? nla_parse+0xab/0x230
[ 1239.229091]  ? nft_get_set_elem+0x440/0x440 [nf_tables]
[ 1239.229091]  nfnetlink_rcv_msg+0x7f0/0xab0 [nfnetlink]
[ 1239.229091]  ? nfnetlink_bind+0x1d0/0x1d0 [nfnetlink]
[ 1239.229091]  ? debug_show_all_locks+0x290/0x290
[ 1239.229091]  ? sched_clock_cpu+0x132/0x170
[ 1239.229091]  ? find_held_lock+0x39/0x1b0
[ 1239.229091]  ? sched_clock_local+0x10d/0x130
[ 1239.229091]  netlink_rcv_skb+0x211/0x320
[ 1239.229091]  ? nfnetlink_bind+0x1d0/0x1d0 [nfnetlink]
[ 1239.229091]  ? netlink_ack+0x7b0/0x7b0
[ 1239.229091]  ? ns_capable_common+0x6e/0x110
[ 1239.229091]  nfnetlink_rcv+0x2d1/0x310 [nfnetlink]
[ 1239.229091]  ? nfnetlink_rcv_batch+0x10f0/0x10f0 [nfnetlink]
[ 1239.229091]  ? netlink_deliver_tap+0x829/0x930
[ 1239.229091]  ? lock_acquire+0x265/0x2e0
[ 1239.229091]  netlink_unicast+0x406/0x520
[ 1239.509725]  ? netlink_attachskb+0x5b0/0x5b0
[ 1239.509725]  ? find_held_lock+0x39/0x1b0
[ 1239.509725]  netlink_sendmsg+0x987/0xa20
[ 1239.509725]  ? netlink_unicast+0x520/0x520
[ 1239.509725]  ? _copy_from_user+0xa9/0xc0
[ 1239.509725]  __sys_sendto+0x21a/0x2c0
[ 1239.509725]  ? __ia32_sys_getpeername+0xa0/0xa0
[ 1239.509725]  ? retint_kernel+0x10/0x10
[ 1239.509725]  ? sched_clock_cpu+0x132/0x170
[ 1239.509725]  ? find_held_lock+0x39/0x1b0
[ 1239.509725]  ? lock_downgrade+0x540/0x540
[ 1239.509725]  ? up_read+0x1c/0x100
[ 1239.509725]  ? __do_page_fault+0x763/0x970
[ 1239.509725]  ? retint_user+0x18/0x18
[ 1239.509725]  __x64_sys_sendto+0x177/0x180
[ 1239.509725]  do_syscall_64+0xaa/0x360
[ 1239.509725]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 1239.509725] RIP: 0033:0x7f5a8f468e03
[ 1239.509725] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb d0 0f 1f 84 00 00 00 00 00 83 3d 49 c9 2b 00 00 75 13 49 89 ca b8 2c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8
[ 1239.509725] RSP: 002b:00007ffd78d0b778 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[ 1239.509725] RAX: ffffffffffffffda RBX: 00007ffd78d0c890 RCX: 00007f5a8f468e03
[ 1239.509725] RDX: 0000000000000034 RSI: 00007ffd78d0b7e0 RDI: 0000000000000003
[ 1239.509725] RBP: 00007ffd78d0b7d0 R08: 00007f5a8f15c160 R09: 000000000000000c
[ 1239.509725] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd78d0b7e0
[ 1239.509725] R13: 0000000000000034 R14: 00007f5a8f9aff60 R15: 00005648040094b0
[ 1239.509725] Modules linked in: nf_tables_set nf_tables nfnetlink ip_tables x_tables
[ 1239.670713] ---[ end trace 39375adcda140f11 ]---
[ 1239.676016] RIP: 0010:nft_hash_walk+0x1d2/0x310 [nf_tables_set]
[ 1239.682834] Code: 84 d2 7f 10 4c 89 e7 89 44 24 38 e8 d8 5a 17 e0 8b 44 24 38 48 8d 7b 10 41 0f b6 0c 24 48 89 fa 48 89 fe 48 c1 ea 03 83 e6 07 <42> 0f b6 14 3a 40 38 f2 7f 1a 84 d2 74 16
[ 1239.705108] RSP: 0018:ffff8801118cf358 EFLAGS: 00010246
[ 1239.711115] RAX: 0000000000000000 RBX: 0000000000020400 RCX: 0000000000000001
[ 1239.719269] RDX: 0000000000004082 RSI: 0000000000000000 RDI: 0000000000020410
[ 1239.727401] RBP: ffff880114d5a988 R08: 0000000000007e94 R09: ffff880114dd8030
[ 1239.735530] R10: ffff880114d5a988 R11: ffffed00229bb006 R12: ffff8801118cf4d0
[ 1239.743658] R13: ffff8801118cf4d8 R14: 0000000000000000 R15: dffffc0000000000
[ 1239.751785] FS:  00007f5a8fe0b700(0000) GS:ffff88011b600000(0000) knlGS:0000000000000000
[ 1239.760993] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1239.767560] CR2: 00007f5a8ecc27b0 CR3: 000000010608e000 CR4: 00000000001006f0
[ 1239.775679] Kernel panic - not syncing: Fatal exception
[ 1239.776630] Kernel Offset: 0x1f000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[ 1239.776630] Rebooting in 5 seconds..

Fixes: 20a69341f2d0 ("netfilter: nf_tables: add netlink set API")
Signed-off-by: Taehee Yoo 
Signed-off-by: Pablo Neira Ayuso 
[bwh: Backported to 3.16:
 - Drop changes to nft_rhash_privsize() and in nft_set_bitmap.c
 - Adjust filenames]
Signed-off-by: Ben Hutchings

vsock: split dwork to avoid reinitializations

2018-11-20T18:05:54+00:00

commit 455f05ecd2b219e9a216050796d30c830d9bc393 upstream.

syzbot reported that we reinitialize an active delayed
work in vsock_stream_connect():

	ODEBUG: init active (active state 0) object type: timer_list hint:
	delayed_work_timer_fn+0x0/0x90 kernel/workqueue.c:1414
	WARNING: CPU: 1 PID: 11518 at lib/debugobjects.c:329
	debug_print_object+0x16a/0x210 lib/debugobjects.c:326

The pattern is apparently wrong, we should only initialize
the dealyed work once and could repeatly schedule it. So we
have to move out the initializations to allocation side.
And to avoid confusion, we can split the shared dwork
into two, instead of re-using the same one.

Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Reported-by: 
Cc: Andy king 
Cc: Stefan Hajnoczi 
Cc: Jorgen Hansen 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

netfilter: ipv6: nf_defrag: reduce struct net memory waste

2018-11-20T18:05:17+00:00

commit 9ce7bc036ae4cfe3393232c86e9e1fea2153c237 upstream.

It is a waste of memory to use a full "struct netns_sysctl_ipv6"
while only one pointer is really used, considering netns_sysctl_ipv6
keeps growing.

Also, since "struct netns_frags" has cache line alignment,
it is better to move the frags_hdr pointer outside, otherwise
we spend a full cache line for this pointer.

This saves 192 bytes of memory per netns.

Fixes: c038a767cd69 ("ipv6: add a new namespace for nf_conntrack_reasm")
Signed-off-by: Eric Dumazet 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

soreuseport: initialise timewait reuseport field

2018-10-21T07:45:18+00:00

commit 3099a52918937ab86ec47038ad80d377ba16c531 upstream.

syzbot reported an uninit-value in inet_csk_bind_conflict() [1]

It turns out we never propagated sk->sk_reuseport into timewait socket.

[1]
BUG: KMSAN: uninit-value in inet_csk_bind_conflict+0x5f9/0x990 net/ipv4/inet_connection_sock.c:151
CPU: 1 PID: 3589 Comm: syzkaller008242 Not tainted 4.16.0+ #82
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+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676
 inet_csk_bind_conflict+0x5f9/0x990 net/ipv4/inet_connection_sock.c:151
 inet_csk_get_port+0x1d28/0x1e40 net/ipv4/inet_connection_sock.c:320
 inet6_bind+0x121c/0x1820 net/ipv6/af_inet6.c:399
 SYSC_bind+0x3f2/0x4b0 net/socket.c:1474
 SyS_bind+0x54/0x80 net/socket.c:1460
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x4416e9
RSP: 002b:00007ffce6d15c88 EFLAGS: 00000217 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 0100000000000000 RCX: 00000000004416e9
RDX: 000000000000001c RSI: 0000000020402000 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00000000e6d15e08 R09: 00000000e6d15e08
R10: 0000000000000004 R11: 0000000000000217 R12: 0000000000009478
R13: 00000000006cd448 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521
 tcp_time_wait+0xf17/0xf50 net/ipv4/tcp_minisocks.c:283
 tcp_rcv_state_process+0xebe/0x6490 net/ipv4/tcp_input.c:6003
 tcp_v6_do_rcv+0x11dd/0x1d90 net/ipv6/tcp_ipv6.c:1331
 sk_backlog_rcv include/net/sock.h:908 [inline]
 __release_sock+0x2d6/0x680 net/core/sock.c:2271
 release_sock+0x97/0x2a0 net/core/sock.c:2786
 tcp_close+0x277/0x18f0 net/ipv4/tcp.c:2269
 inet_release+0x240/0x2a0 net/ipv4/af_inet.c:427
 inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:435
 sock_release net/socket.c:595 [inline]
 sock_close+0xe0/0x300 net/socket.c:1149
 __fput+0x49e/0xa10 fs/file_table.c:209
 ____fput+0x37/0x40 fs/file_table.c:243
 task_work_run+0x243/0x2c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x10e1/0x38d0 kernel/exit.c:867
 do_group_exit+0x1a0/0x360 kernel/exit.c:970
 SYSC_exit_group+0x21/0x30 kernel/exit.c:981
 SyS_exit_group+0x25/0x30 kernel/exit.c:979
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521
 inet_twsk_alloc+0xaef/0xc00 net/ipv4/inet_timewait_sock.c:182
 tcp_time_wait+0xd9/0xf50 net/ipv4/tcp_minisocks.c:258
 tcp_rcv_state_process+0xebe/0x6490 net/ipv4/tcp_input.c:6003
 tcp_v6_do_rcv+0x11dd/0x1d90 net/ipv6/tcp_ipv6.c:1331
 sk_backlog_rcv include/net/sock.h:908 [inline]
 __release_sock+0x2d6/0x680 net/core/sock.c:2271
 release_sock+0x97/0x2a0 net/core/sock.c:2786
 tcp_close+0x277/0x18f0 net/ipv4/tcp.c:2269
 inet_release+0x240/0x2a0 net/ipv4/af_inet.c:427
 inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:435
 sock_release net/socket.c:595 [inline]
 sock_close+0xe0/0x300 net/socket.c:1149
 __fput+0x49e/0xa10 fs/file_table.c:209
 ____fput+0x37/0x40 fs/file_table.c:243
 task_work_run+0x243/0x2c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x10e1/0x38d0 kernel/exit.c:867
 do_group_exit+0x1a0/0x360 kernel/exit.c:970
 SYSC_exit_group+0x21/0x30 kernel/exit.c:981
 SyS_exit_group+0x25/0x30 kernel/exit.c:979
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314
 kmem_cache_alloc+0xaab/0xb90 mm/slub.c:2756
 inet_twsk_alloc+0x13b/0xc00 net/ipv4/inet_timewait_sock.c:163
 tcp_time_wait+0xd9/0xf50 net/ipv4/tcp_minisocks.c:258
 tcp_rcv_state_process+0xebe/0x6490 net/ipv4/tcp_input.c:6003
 tcp_v6_do_rcv+0x11dd/0x1d90 net/ipv6/tcp_ipv6.c:1331
 sk_backlog_rcv include/net/sock.h:908 [inline]
 __release_sock+0x2d6/0x680 net/core/sock.c:2271
 release_sock+0x97/0x2a0 net/core/sock.c:2786
 tcp_close+0x277/0x18f0 net/ipv4/tcp.c:2269
 inet_release+0x240/0x2a0 net/ipv4/af_inet.c:427
 inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:435
 sock_release net/socket.c:595 [inline]
 sock_close+0xe0/0x300 net/socket.c:1149
 __fput+0x49e/0xa10 fs/file_table.c:209
 ____fput+0x37/0x40 fs/file_table.c:243
 task_work_run+0x243/0x2c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x10e1/0x38d0 kernel/exit.c:867
 do_group_exit+0x1a0/0x360 kernel/exit.c:970
 SYSC_exit_group+0x21/0x30 kernel/exit.c:981
 SyS_exit_group+0x25/0x30 kernel/exit.c:979
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Fixes: da5e36308d9f ("soreuseport: TCP/IPv4 implementation")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

net: fix rtnh_ok()

2018-10-21T07:45:17+00:00

commit b1993a2de12c9e75c35729e2ffbc3a92d50c0d31 upstream.

syzbot reported :

BUG: KMSAN: uninit-value in rtnh_ok include/net/nexthop.h:11 [inline]
BUG: KMSAN: uninit-value in fib_count_nexthops net/ipv4/fib_semantics.c:469 [inline]
BUG: KMSAN: uninit-value in fib_create_info+0x554/0x8d20 net/ipv4/fib_semantics.c:1091

@remaining is an integer, coming from user space.
If it is negative we want rtnh_ok() to return false.

Fixes: 4e902c57417c ("[IPv4]: FIB configuration using struct fib_config")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: core: dst: Add kernel-doc for 'net' parameter

2018-10-21T07:44:52+00:00

commit 8eb1a8590f5ca114fabf16ebb26a4bce0255ace9 upstream.

This fixes the following kernel-doc warning:

./include/net/dst.h:366: warning: Function parameter or member 'net' not described in 'skb_tunnel_rx'

Fixes: ea23192e8e57 ("tunnels: harmonize cleanup done on skb on rx path")
Signed-off-by: Jonathan Neuschäfer 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

ipv4: lock mtu in fnhe when received PMTU < net.ipv4.route.min_pmtu

2018-06-16T21:22:39+00:00

commit d52e5a7e7ca49457dd31fc8b42fb7c0d58a31221 upstream.

Prior to the rework of PMTU information storage in commit
2c8cec5c10bc ("ipv4: Cache learned PMTU information in inetpeer."),
when a PMTU event advertising a PMTU smaller than
net.ipv4.route.min_pmtu was received, we would disable setting the DF
flag on packets by locking the MTU metric, and set the PMTU to
net.ipv4.route.min_pmtu.

Since then, we don't disable DF, and set PMTU to
net.ipv4.route.min_pmtu, so the intermediate router that has this link
with a small MTU will have to drop the packets.

This patch reestablishes pre-2.6.39 behavior by splitting
rtable->rt_pmtu into a bitfield with rt_mtu_locked and rt_pmtu.
rt_mtu_locked indicates that we shouldn't set the DF bit on that path,
and is checked in ip_dont_fragment().

One possible workaround is to set net.ipv4.route.min_pmtu to a value low
enough to accommodate the lowest MTU encountered.

Fixes: 2c8cec5c10bc ("ipv4: Cache learned PMTU information in inetpeer.")
Signed-off-by: Sabrina Dubroca 
Reviewed-by: Stefano Brivio 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings