linux-toradex.git/net/ipv4/ip_output.c, branch v5.5

inet: protect against too small mtu values.

2019-12-07T19:55:11+00:00

syzbot was once again able to crash a host by setting a very small mtu
on loopback device.

Let's make inetdev_valid_mtu() available in include/net/ip.h,
and use it in ip_setup_cork(), so that we protect both ip_append_page()
and __ip_append_data()

Also add a READ_ONCE() when the device mtu is read.

Pairs this lockless read with one WRITE_ONCE() in __dev_set_mtu(),
even if other code paths might write over this field.

Add a big comment in include/linux/netdevice.h about dev->mtu
needing READ_ONCE()/WRITE_ONCE() annotations.

Hopefully we will add the missing ones in followup patches.

[1]

refcount_t: saturated; leaking memory.
WARNING: CPU: 0 PID: 9464 at lib/refcount.c:22 refcount_warn_saturate+0x138/0x1f0 lib/refcount.c:22
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 9464 Comm: syz-executor850 Not tainted 5.4.0-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
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x3e kernel/panic.c:582
 report_bug+0x289/0x300 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 fixup_bug arch/x86/kernel/traps.c:169 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:refcount_warn_saturate+0x138/0x1f0 lib/refcount.c:22
Code: 06 31 ff 89 de e8 c8 f5 e6 fd 84 db 0f 85 6f ff ff ff e8 7b f4 e6 fd 48 c7 c7 e0 71 4f 88 c6 05 56 a6 a4 06 01 e8 c7 a8 b7 fd <0f> 0b e9 50 ff ff ff e8 5c f4 e6 fd 0f b6 1d 3d a6 a4 06 31 ff 89
RSP: 0018:ffff88809689f550 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815e4336 RDI: ffffed1012d13e9c
RBP: ffff88809689f560 R08: ffff88809c50a3c0 R09: fffffbfff15d31b1
R10: fffffbfff15d31b0 R11: ffffffff8ae98d87 R12: 0000000000000001
R13: 0000000000040100 R14: ffff888099041104 R15: ffff888218d96e40
 refcount_add include/linux/refcount.h:193 [inline]
 skb_set_owner_w+0x2b6/0x410 net/core/sock.c:1999
 sock_wmalloc+0xf1/0x120 net/core/sock.c:2096
 ip_append_page+0x7ef/0x1190 net/ipv4/ip_output.c:1383
 udp_sendpage+0x1c7/0x480 net/ipv4/udp.c:1276
 inet_sendpage+0xdb/0x150 net/ipv4/af_inet.c:821
 kernel_sendpage+0x92/0xf0 net/socket.c:3794
 sock_sendpage+0x8b/0xc0 net/socket.c:936
 pipe_to_sendpage+0x2da/0x3c0 fs/splice.c:458
 splice_from_pipe_feed fs/splice.c:512 [inline]
 __splice_from_pipe+0x3ee/0x7c0 fs/splice.c:636
 splice_from_pipe+0x108/0x170 fs/splice.c:671
 generic_splice_sendpage+0x3c/0x50 fs/splice.c:842
 do_splice_from fs/splice.c:861 [inline]
 direct_splice_actor+0x123/0x190 fs/splice.c:1035
 splice_direct_to_actor+0x3b4/0xa30 fs/splice.c:990
 do_splice_direct+0x1da/0x2a0 fs/splice.c:1078
 do_sendfile+0x597/0xd00 fs/read_write.c:1464
 __do_sys_sendfile64 fs/read_write.c:1525 [inline]
 __se_sys_sendfile64 fs/read_write.c:1511 [inline]
 __x64_sys_sendfile64+0x1dd/0x220 fs/read_write.c:1511
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441409
Code: e8 ac e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffb64c4f78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441409
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005
RBP: 0000000000073b8a R08: 0000000000000010 R09: 0000000000000010
R10: 0000000000010001 R11: 0000000000000246 R12: 0000000000402180
R13: 0000000000402210 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

Fixes: 1470ddf7f8ce ("inet: Remove explicit write references to sk/inet in ip_append_data")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Signed-off-by: David S. Miller

netfilter: Support iif matches in POSTROUTING

2019-11-15T22:44:48+00:00

Instead of generally passing NULL to NF_HOOK_COND() for input device,
pass skb->dev which contains input device for routed skbs.

Note that iptables (both legacy and nft) reject rules with input
interface match from being added to POSTROUTING chains, but nftables
allows this.

Cc: Eric Garver 
Signed-off-by: Phil Sutter 
Signed-off-by: Pablo Neira Ayuso

ipv4: fix IPSKB_FRAG_PMTU handling with fragmentation

2019-10-21T17:46:42+00:00

This patch removes the iph field from the state structure, which is not
properly initialized. Instead, add a new field to make the "do we want
to set DF" be the state bit and move the code to set the DF flag from
ip_frag_next().

Joint work with Pablo and Linus.

Fixes: 19c3401a917b ("net: ipv4: place control buffer handling away from fragmentation iterators")
Reported-by: Patrick Schönthaler 
Signed-off-by: Eric Dumazet 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Linus Torvalds 
Signed-off-by: David S. Miller

net: ensure correct skb->tstamp in various fragmenters

2019-10-18T17:02:37+00:00

Thomas found that some forwarded packets would be stuck
in FQ packet scheduler because their skb->tstamp contained
timestamps far in the future.

We thought we addressed this point in commit 8203e2d844d3
("net: clear skb->tstamp in forwarding paths") but there
is still an issue when/if a packet needs to be fragmented.

In order to meet EDT requirements, we have to make sure all
fragments get the original skb->tstamp.

Note that this original skb->tstamp should be zero in
forwarding path, but might have a non zero value in
output path if user decided so.

Fixes: fb420d5d91c1 ("tcp/fq: move back to CLOCK_MONOTONIC")
Signed-off-by: Eric Dumazet 
Reported-by: Thomas Bartschies 
Signed-off-by: David S. Miller

tcp: honor SO_PRIORITY in TIME_WAIT state

2019-09-27T10:05:02+00:00

ctl packets sent on behalf of TIME_WAIT sockets currently
have a zero skb->priority, which can cause various problems.

In this patch we :

- add a tw_priority field in struct inet_timewait_sock.

- populate it from sk->sk_priority when a TIME_WAIT is created.

- For IPv4, change ip_send_unicast_reply() and its two
  callers to propagate tw_priority correctly.
  ip_send_unicast_reply() no longer changes sk->sk_priority.

- For IPv6, make sure TIME_WAIT sockets pass their tw_priority
  field to tcp_v6_send_response() and tcp_v6_send_ack().

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

ipv4: Revert removal of rt_uses_gateway

2019-09-21T01:23:33+00:00

Julian noted that rt_uses_gateway has a more subtle use than 'is gateway
set':
    https://lore.kernel.org/netdev/alpine.LFD.2.21.1909151104060.2546@ja.home.ssi.bg/

Revert that part of the commit referenced in the Fixes tag.

Currently, there are no u8 holes in 'struct rtable'. There is a 4-byte hole
in the second cacheline which contains the gateway declaration. So move
rt_gw_family down to the gateway declarations since they are always used
together, and then re-use that u8 for rt_uses_gateway. End result is that
rtable size is unchanged.

Fixes: 1550c171935d ("ipv4: Prepare rtable for IPv6 gateway")
Reported-by: Julian Anastasov 
Signed-off-by: David Ahern 
Reviewed-by: Julian Anastasov 
Signed-off-by: Jakub Kicinski

ip: support SO_MARK cmsg

2019-09-13T19:44:19+00:00

Enable setting skb->mark for UDP and RAW sockets using cmsg.

This is analogous to existing support for TOS, TTL, txtime, etc.

Packet sockets already support this as of commit c7d39e32632e
("packet: support per-packet fwmark for af_packet sendmsg").

Similar to other fields, implement by
1. initialize the sockcm_cookie.mark from socket option sk_mark
2. optionally overwrite this in ip_cmsg_send/ip6_datagram_send_ctl
3. initialize inet_cork.mark from sockcm_cookie.mark
4. initialize each (usually just one) skb->mark from inet_cork.mark

Step 1 is handled in one location for most protocols by ipcm_init_sk
as of commit 351782067b6b ("ipv4: ipcm_cookie initializers").

Signed-off-by: Willem de Bruijn 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2019-06-28T04:06:39+00:00

The new route handling in ip_mc_finish_output() from 'net' overlapped
with the new support for returning congestion notifications from BPF
programs.

In order to handle this I had to take the dev_loopback_xmit() calls
out of the switch statement.

The aquantia driver conflicts were simple overlapping changes.

Signed-off-by: David S. Miller

ipv4: reset rt_iif for recirculated mcast/bcast out pkts

2019-06-26T19:40:10+00:00

Multicast or broadcast egress packets have rt_iif set to the oif. These
packets might be recirculated back as input and lookup to the raw
sockets may fail because they are bound to the incoming interface
(skb_iif). If rt_iif is not zero, during the lookup, inet_iif() function
returns rt_iif instead of skb_iif. Hence, the lookup fails.

v2: Make it non vrf specific (David Ahern). Reword the changelog to
    reflect it.
Signed-off-by: Stephen Suryaputra 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2019-06-18T03:20:36+00:00

Honestly all the conflicts were simple overlapping changes,
nothing really interesting to report.

Signed-off-by: David S. Miller