linux-stable.git/net/ipv4, branch v5.4.16

xfrm: support output_mark for offload ESP packets

2020-01-29T15:45:31+00:00

commit 4e4362d2bf2a49ff44dbbc9585207977ca3d71d0 upstream.

Commit 9b42c1f179a6 ("xfrm: Extend the output_mark") added output_mark
support but missed ESP offload support.

xfrm_smark_get() is not called within xfrm_input() for packets coming
from esp4_gro_receive() or esp6_gro_receive(). Therefore call
xfrm_smark_get() directly within these functions.

Fixes: 9b42c1f179a6 ("xfrm: Extend the output_mark to support input direction and masking.")
Signed-off-by: Ulrich Weber 
Signed-off-by: Steffen Klassert 
Signed-off-by: Greg Kroah-Hartman

ipv4: Detect rollover in specific fib table dump

2020-01-29T15:45:24+00:00

[ Upstream commit 9827c0634e461703abf81e8cc8b7adf5da5886d0 ]

Sven-Haegar reported looping on fib dumps when 255.255.255.255 route has
been added to a table. The looping is caused by the key rolling over from
FFFFFFFF to 0. When dumping a specific table only, we need a means to detect
when the table dump is done. The key and count saved to cb args are both 0
only at the start of the table dump. If key is 0 and count > 0, then we are
in the rollover case. Detect and return to avoid looping.

This only affects dumps of a specific table; for dumps of all tables
(the case prior to the change in the Fixes tag) inet_dump_fib moved
the entry counter to the next table and reset the cb args used by
fib_table_dump and fn_trie_dump_leaf, so the rollover ffffffff back
to 0 did not cause looping with the dumps.

Fixes: effe67926624 ("net: Enable kernel side filtering of route dumps")
Reported-by: Sven-Haegar Koch 
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

fou: Fix IPv6 netlink policy

2020-01-29T15:45:22+00:00

[ Upstream commit bb48eb9b12a95db9d679025927269d4adda6dbd1 ]

When submitting v2 of "fou: Support binding FoU socket" (1713cb37bf67),
I accidentally sent the wrong version of the patch and one fix was
missing. In the initial version of the patch, as well as the version 2
that I submitted, I incorrectly used ".type" for the two V6-attributes.
The correct is to use ".len".

Reported-by: Dmitry Vyukov 
Fixes: 1713cb37bf67 ("fou: Support binding FoU socket")
Signed-off-by: Kristian Evensen 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: do not leave dangling pointers in tp->highest_sack

2020-01-29T15:45:22+00:00

[ Upstream commit 2bec445f9bf35e52e395b971df48d3e1e5dc704a ]

Latest commit 853697504de0 ("tcp: Fix highest_sack and highest_sack_seq")
apparently allowed syzbot to trigger various crashes in TCP stack [1]

I believe this commit only made things easier for syzbot to find
its way into triggering use-after-frees. But really the bugs
could lead to bad TCP behavior or even plain crashes even for
non malicious peers.

I have audited all calls to tcp_rtx_queue_unlink() and
tcp_rtx_queue_unlink_and_free() and made sure tp->highest_sack would be updated
if we are removing from rtx queue the skb that tp->highest_sack points to.

These updates were missing in three locations :

1) tcp_clean_rtx_queue() [This one seems quite serious,
                          I have no idea why this was not caught earlier]

2) tcp_rtx_queue_purge() [Probably not a big deal for normal operations]

3) tcp_send_synack()     [Probably not a big deal for normal operations]

[1]
BUG: KASAN: use-after-free in tcp_highest_sack_seq include/net/tcp.h:1864 [inline]
BUG: KASAN: use-after-free in tcp_highest_sack_seq include/net/tcp.h:1856 [inline]
BUG: KASAN: use-after-free in tcp_check_sack_reordering+0x33c/0x3a0 net/ipv4/tcp_input.c:891
Read of size 4 at addr ffff8880a488d068 by task ksoftirqd/1/16

CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.5.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:639
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:134
 tcp_highest_sack_seq include/net/tcp.h:1864 [inline]
 tcp_highest_sack_seq include/net/tcp.h:1856 [inline]
 tcp_check_sack_reordering+0x33c/0x3a0 net/ipv4/tcp_input.c:891
 tcp_try_undo_partial net/ipv4/tcp_input.c:2730 [inline]
 tcp_fastretrans_alert+0xf74/0x23f0 net/ipv4/tcp_input.c:2847
 tcp_ack+0x2577/0x5bf0 net/ipv4/tcp_input.c:3710
 tcp_rcv_established+0x6dd/0x1e90 net/ipv4/tcp_input.c:5706
 tcp_v4_do_rcv+0x619/0x8d0 net/ipv4/tcp_ipv4.c:1619
 tcp_v4_rcv+0x307f/0x3b40 net/ipv4/tcp_ipv4.c:2001
 ip_protocol_deliver_rcu+0x5a/0x880 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x23b/0x380 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip_local_deliver+0x1e9/0x520 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish+0x1db/0x2f0 net/ipv4/ip_input.c:428
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip_rcv+0xe8/0x3f0 net/ipv4/ip_input.c:538
 __netif_receive_skb_one_core+0x113/0x1a0 net/core/dev.c:5148
 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5262
 process_backlog+0x206/0x750 net/core/dev.c:6093
 napi_poll net/core/dev.c:6530 [inline]
 net_rx_action+0x508/0x1120 net/core/dev.c:6598
 __do_softirq+0x262/0x98c kernel/softirq.c:292
 run_ksoftirqd kernel/softirq.c:603 [inline]
 run_ksoftirqd+0x8e/0x110 kernel/softirq.c:595
 smpboot_thread_fn+0x6a3/0xa40 kernel/smpboot.c:165
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Allocated by task 10091:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:486
 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:521
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc_node mm/slab.c:3263 [inline]
 kmem_cache_alloc_node+0x138/0x740 mm/slab.c:3575
 __alloc_skb+0xd5/0x5e0 net/core/skbuff.c:198
 alloc_skb_fclone include/linux/skbuff.h:1099 [inline]
 sk_stream_alloc_skb net/ipv4/tcp.c:875 [inline]
 sk_stream_alloc_skb+0x113/0xc90 net/ipv4/tcp.c:852
 tcp_sendmsg_locked+0xcf9/0x3470 net/ipv4/tcp.c:1282
 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1432
 inet_sendmsg+0x9e/0xe0 net/ipv4/af_inet.c:807
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:672
 __sys_sendto+0x262/0x380 net/socket.c:1998
 __do_sys_sendto net/socket.c:2010 [inline]
 __se_sys_sendto net/socket.c:2006 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:2006
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 10095:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:335 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:474
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:483
 __cache_free mm/slab.c:3426 [inline]
 kmem_cache_free+0x86/0x320 mm/slab.c:3694
 kfree_skbmem+0x178/0x1c0 net/core/skbuff.c:645
 __kfree_skb+0x1e/0x30 net/core/skbuff.c:681
 sk_eat_skb include/net/sock.h:2453 [inline]
 tcp_recvmsg+0x1252/0x2930 net/ipv4/tcp.c:2166
 inet_recvmsg+0x136/0x610 net/ipv4/af_inet.c:838
 sock_recvmsg_nosec net/socket.c:886 [inline]
 sock_recvmsg net/socket.c:904 [inline]
 sock_recvmsg+0xce/0x110 net/socket.c:900
 __sys_recvfrom+0x1ff/0x350 net/socket.c:2055
 __do_sys_recvfrom net/socket.c:2073 [inline]
 __se_sys_recvfrom net/socket.c:2069 [inline]
 __x64_sys_recvfrom+0xe1/0x1a0 net/socket.c:2069
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880a488d040
 which belongs to the cache skbuff_fclone_cache of size 456
The buggy address is located 40 bytes inside of
 456-byte region [ffff8880a488d040, ffff8880a488d208)
The buggy address belongs to the page:
page:ffffea0002922340 refcount:1 mapcount:0 mapping:ffff88821b057000 index:0x0
raw: 00fffe0000000200 ffffea00022a5788 ffffea0002624a48 ffff88821b057000
raw: 0000000000000000 ffff8880a488d040 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a488cf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a488cf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a488d000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                                          ^
 ffff8880a488d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a488d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

Fixes: 853697504de0 ("tcp: Fix highest_sack and highest_sack_seq")
Fixes: 50895b9de1d3 ("tcp: highest_sack fix")
Fixes: 737ff314563c ("tcp: use sequence distance to detect reordering")
Signed-off-by: Eric Dumazet 
Cc: Cambda Zhu 
Cc: Yuchung Cheng 
Cc: Neal Cardwell 
Acked-by: Neal Cardwell 
Acked-by: Yuchung Cheng 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp_bbr: improve arithmetic division in bbr_update_bw()

2020-01-29T15:45:21+00:00

[ Upstream commit 5b2f1f3070b6447b76174ea8bfb7390dc6253ebd ]

do_div() does a 64-by-32 division. Use div64_long() instead of it
if the divisor is long, to avoid truncation to 32-bit.
And as a nice side effect also cleans up the function a bit.

Signed-off-by: Wen Yang 
Cc: Eric Dumazet 
Cc: "David S. Miller" 
Cc: Alexey Kuznetsov 
Cc: Hideaki YOSHIFUJI 
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

Revert "udp: do rmem bulk free even if the rx sk queue is empty"

2020-01-29T15:45:21+00:00

[ Upstream commit d39ca2590d10712f412add7a88e1dd467a7246f4 ]

This reverts commit 0d4a6608f68c7532dcbfec2ea1150c9761767d03.

Willem reported that after commit 0d4a6608f68c ("udp: do rmem bulk
free even if the rx sk queue is empty") the memory allocated by
an almost idle system with many UDP sockets can grow a lot.

For stable kernel keep the solution as simple as possible and revert
the offending commit.

Reported-by: Willem de Bruijn 
Diagnosed-by: Eric Dumazet 
Fixes: 0d4a6608f68c ("udp: do rmem bulk free even if the rx sk queue is empty")
Signed-off-by: Paolo Abeni 
Acked-by: Willem de Bruijn 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net, ip_tunnel: fix namespaces move

2020-01-29T15:45:20+00:00

[ Upstream commit d0f418516022c32ecceaf4275423e5bd3f8743a9 ]

in the same manner as commit 690afc165bb3 ("net: ip6_gre: fix moving
ip6gre between namespaces"), fix namespace moving as it was broken since
commit 2e15ea390e6f ("ip_gre: Add support to collect tunnel metadata.").
Indeed, the ip6_gre commit removed the local flag for collect_md
condition, so there is no reason to keep it for ip_gre/ip_tunnel.

this patch will fix both ip_tunnel and ip_gre modules.

Fixes: 2e15ea390e6f ("ip_gre: Add support to collect tunnel metadata.")
Signed-off-by: William Dauchy 
Acked-by: Nicolas Dichtel 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: refine rule to allow EPOLLOUT generation under mem pressure

2020-01-23T07:22:54+00:00

commit 216808c6ba6d00169fd2aa928ec3c0e63bef254f upstream.

At the time commit ce5ec440994b ("tcp: ensure epoll edge trigger
wakeup when write queue is empty") was added to the kernel,
we still had a single write queue, combining rtx and write queues.

Once we moved the rtx queue into a separate rb-tree, testing
if sk_write_queue is empty has been suboptimal.

Indeed, if we have packets in the rtx queue, we probably want
to delay the EPOLLOUT generation at the time incoming packets
will free them, making room, but more importantly avoiding
flooding application with EPOLLOUT events.

Solution is to use tcp_rtx_and_write_queues_empty() helper.

Fixes: 75c119afe14f ("tcp: implement rb-tree based retransmit queue")
Signed-off-by: Eric Dumazet 
Cc: Jason Baron 
Cc: Neal Cardwell 
Acked-by: Soheil Hassas Yeganeh 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

tcp: fix marked lost packets not being retransmitted

2020-01-23T07:22:51+00:00

[ Upstream commit e176b1ba476cf36f723cfcc7a9e57f3cb47dec70 ]

When the packet pointed to by retransmit_skb_hint is unlinked by ACK,
retransmit_skb_hint will be set to NULL in tcp_clean_rtx_queue().
If packet loss is detected at this time, retransmit_skb_hint will be set
to point to the current packet loss in tcp_verify_retransmit_hint(),
then the packets that were previously marked lost but not retransmitted
due to the restriction of cwnd will be skipped and cannot be
retransmitted.

To fix this, when retransmit_skb_hint is NULL, retransmit_skb_hint can
be reset only after all marked lost packets are retransmitted
(retrans_out >= lost_out), otherwise we need to traverse from
tcp_rtx_queue_head in tcp_xmit_retransmit_queue().

Packetdrill to demonstrate:

// Disable RACK and set max_reordering to keep things simple
    0 `sysctl -q net.ipv4.tcp_recovery=0`
   +0 `sysctl -q net.ipv4.tcp_max_reordering=3`

// Establish a connection
   +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
   +0 bind(3, ..., ...) = 0
   +0 listen(3, 1) = 0

  +.1 < S 0:0(0) win 32792 
   +0 > S. 0:0(0) ack 1 <...>
 +.01 < . 1:1(0) ack 1 win 257
   +0 accept(3, ..., ...) = 4

// Send 8 data segments
   +0 write(4, ..., 8000) = 8000
   +0 > P. 1:8001(8000) ack 1

// Enter recovery and 1:3001 is marked lost
 +.01 < . 1:1(0) ack 1 win 257 
   +0 < . 1:1(0) ack 1 win 257 
   +0 < . 1:1(0) ack 1 win 257 

// Retransmit 1:1001, now retransmit_skb_hint points to 1001:2001
   +0 > . 1:1001(1000) ack 1

// 1001:2001 was ACKed causing retransmit_skb_hint to be set to NULL
 +.01 < . 1:1(0) ack 2001 win 257 
// Now retransmit_skb_hint points to 4001:5001 which is now marked lost

// BUG: 2001:3001 was not retransmitted
   +0 > . 2001:3001(1000) ack 1

Signed-off-by: Pengcheng Yang 
Acked-by: Neal Cardwell 
Tested-by: Neal Cardwell 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

netfilter: arp_tables: init netns pointer in xt_tgdtor_param struct

2020-01-23T07:22:47+00:00

commit 212e7f56605ef9688d0846db60c6c6ec06544095 upstream.

An earlier commit (1b789577f655060d98d20e,
"netfilter: arp_tables: init netns pointer in xt_tgchk_param struct")
fixed missing net initialization for arptables, but turns out it was
incomplete.  We can get a very similar struct net NULL deref during
error unwinding:

general protection fault: 0000 [#1] PREEMPT SMP KASAN
RIP: 0010:xt_rateest_put+0xa1/0x440 net/netfilter/xt_RATEEST.c:77
 xt_rateest_tg_destroy+0x72/0xa0 net/netfilter/xt_RATEEST.c:175
 cleanup_entry net/ipv4/netfilter/arp_tables.c:509 [inline]
 translate_table+0x11f4/0x1d80 net/ipv4/netfilter/arp_tables.c:587
 do_replace net/ipv4/netfilter/arp_tables.c:981 [inline]
 do_arpt_set_ctl+0x317/0x650 net/ipv4/netfilter/arp_tables.c:1461

Also init the netns pointer in xt_tgdtor_param struct.

Fixes: add67461240c1d ("netfilter: add struct net * to target parameters")
Reported-by: syzbot+91bdd8eece0f6629ec8b@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman