Commit Graph

267 Commits

Author SHA1 Message Date
Eric Dumazet
b26fed25e6 ipv4: avoid using shared IP generator for connected sockets
commit 23f57406b8 upstream.

ip_select_ident_segs() has been very conservative about using
the connected socket private generator only for packets with IP_DF
set, claiming it was needed for some VJ compression implementations.

As mentioned in this referenced document, this can be abused.
(Ref: Off-Path TCP Exploits of the Mixed IPID Assignment)

Before switching to pure random IPID generation and possibly hurt
some workloads, lets use the private inet socket generator.

Not only this will remove one vulnerability, this will also
improve performance of TCP flows using pmtudisc==IP_PMTUDISC_DONT

Fixes: 73f156a6e8 ("inetpeer: get rid of ip_id_count")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reported-by: Ray Che <xijiache@gmail.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01 17:25:44 +01:00
Vadim Fedorenko
4476568069 net: lwtunnel: handle MTU calculation in forwading
[ Upstream commit fade56410c ]

Commit 14972cbd34 ("net: lwtunnel: Handle fragmentation") moved
fragmentation logic away from lwtunnel by carry encap headroom and
use it in output MTU calculation. But the forwarding part was not
covered and created difference in MTU for output and forwarding and
further to silent drops on ipv4 forwarding path. Fix it by taking
into account lwtunnel encap headroom.

The same commit also introduced difference in how to treat RTAX_MTU
in IPv4 and IPv6 where latter explicitly removes lwtunnel encap
headroom from route MTU. Make IPv4 version do the same.

Fixes: 14972cbd34 ("net: lwtunnel: Handle fragmentation")
Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:56:32 +02:00
David S. Miller
8b0308fe31 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Rejecting non-native endian BTF overlapped with the addition
of support for it.

The rest were more simple overlapping changes, except the
renesas ravb binding update, which had to follow a file
move as well as a YAML conversion.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-05 18:40:01 -07:00
Maciej Żenczykowski
02a1b175b0 net/ipv4: always honour route mtu during forwarding
Documentation/networking/ip-sysctl.txt:46 says:
  ip_forward_use_pmtu - BOOLEAN
    By default we don't trust protocol path MTUs while forwarding
    because they could be easily forged and can lead to unwanted
    fragmentation by the router.
    You only need to enable this if you have user-space software
    which tries to discover path mtus by itself and depends on the
    kernel honoring this information. This is normally not the case.
    Default: 0 (disabled)
    Possible values:
    0 - disabled
    1 - enabled

Which makes it pretty clear that setting it to 1 is a potential
security/safety/DoS issue, and yet it is entirely reasonable to want
forwarded traffic to honour explicitly administrator configured
route mtus (instead of defaulting to device mtu).

Indeed, I can't think of a single reason why you wouldn't want to.
Since you configured a route mtu you probably know better...

It is pretty common to have a higher device mtu to allow receiving
large (jumbo) frames, while having some routes via that interface
(potentially including the default route to the internet) specify
a lower mtu.

Note that ipv6 forwarding uses device mtu unless the route is locked
(in which case it will use the route mtu).

This approach is not usable for IPv4 where an 'mtu lock' on a route
also has the side effect of disabling TCP path mtu discovery via
disabling the IPv4 DF (don't frag) bit on all outgoing frames.

I'm not aware of a way to lock a route from an IPv6 RA, so that also
potentially seems wrong.

Signed-off-by: Maciej Żenczykowski <maze@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: Sunmeet Gill (Sunny) <sgill@quicinc.com>
Cc: Vinay Paradkar <vparadka@qti.qualcomm.com>
Cc: Tyler Wear <twear@quicinc.com>
Cc: David Ahern <dsahern@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-24 19:51:16 -07:00
Wei Wang
de033b7d15 ip: pass tos into ip_build_and_send_pkt()
This commit adds tos as a new passed in parameter to
ip_build_and_send_pkt() which will be used in the later commit.
This is a pure restructure and does not have any functional change.

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-10 13:15:40 -07:00
Christoph Hellwig
a7b75c5a8c net: pass a sockptr_t into ->setsockopt
Rework the remaining setsockopt code to pass a sockptr_t instead of a
plain user pointer.  This removes the last remaining set_fs(KERNEL_DS)
outside of architecture specific code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> [ieee802154]
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24 15:41:54 -07:00
Christoph Hellwig
de40a3e883 net/ipv4: merge ip_options_get and ip_options_get_from_user
Use the sockptr_t type to merge the versions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24 15:41:54 -07:00
Christoph Hellwig
b6238c04c0 net/ipv4: remove compat_ip_{get,set}sockopt
Handle the few cases that need special treatment in-line using
in_compat_syscall().

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:16:41 -07:00
Eric Dumazet
05e22e8395 tcp: remove indirect calls for icsk->icsk_af_ops->queue_xmit
Mitigate RETPOLINE costs in __tcp_transmit_skb()
by using INDIRECT_CALL_INET() wrapper.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-20 17:47:53 -07:00
Christoph Hellwig
c1f9ec5776 ipv4: add ip_sock_set_pktinfo
Add a helper to directly set the IP_PKTINFO sockopt from kernel
space without going through a fake uaccess.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28 11:11:45 -07:00
Christoph Hellwig
2de569bda2 ipv4: add ip_sock_set_mtu_discover
Add a helper to directly set the IP_MTU_DISCOVER sockopt from kernel
space without going through a fake uaccess.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com> [rxrpc bits]
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28 11:11:45 -07:00
Christoph Hellwig
db45c0ef25 ipv4: add ip_sock_set_recverr
Add a helper to directly set the IP_RECVERR sockopt from kernel space
without going through a fake uaccess.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28 11:11:45 -07:00
Christoph Hellwig
c4e446bf5a ipv4: add ip_sock_set_freebind
Add a helper to directly set the IP_FREEBIND sockopt from kernel space
without going through a fake uaccess.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28 11:11:45 -07:00
Christoph Hellwig
6ebf71bab9 ipv4: add ip_sock_set_tos
Add a helper to directly set the IP_TOS sockopt from kernel space without
going through a fake uaccess.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28 11:11:45 -07:00
Eric Dumazet
501a90c945 inet: protect against too small mtu values.
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: 1470ddf7f8 ("inet: Remove explicit write references to sk/inet in ip_append_data")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-07 11:55:11 -08:00
Maciej Żenczykowski
66e2f5f7c7 net: inet_is_local_reserved_port() port arg should be unsigned short
Any argument outside of that range would result in an out of bound
memory access, since the accessed array is 65536 bits long.

Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-26 15:15:07 -08:00
Maciej Żenczykowski
82f31ebf61 net: port < inet_prot_sock(net) --> inet_port_requires_bind_service(net, port)
Note that the sysctl write accessor functions guarantee that:
  net->ipv4.sysctl_ip_prot_sock <= net->ipv4.ip_local_ports.range[0]
invariant is maintained, and as such the max() in selinux hooks is actually spurious.

ie. even though
  if (snum < max(inet_prot_sock(sock_net(sk)), low) || snum > high) {
per logic is the same as
  if ((snum < inet_prot_sock(sock_net(sk)) && snum < low) || snum > high) {
it is actually functionally equivalent to:
  if (snum < low || snum > high) {
which is equivalent to:
  if (snum < inet_prot_sock(sock_net(sk)) || snum < low || snum > high) {
even though the first clause is spurious.

But we want to hold on to it in case we ever want to change what what
inet_port_requires_bind_service() means (for example by changing
it from a, by default, [0..1024) range to some sort of set).

Test: builds, git 'grep inet_prot_sock' finds no other references
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-26 13:20:46 -08:00
Maciej Żenczykowski
30429fba99 net: inet_is_local_reserved_port() should return bool not int
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-11-22 16:52:47 -08:00
Eric Dumazet
e7a409c3f4 ipv4: fix IPSKB_FRAG_PMTU handling with fragmentation
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: 19c3401a91 ("net: ipv4: place control buffer handling away from fragmentation iterators")
Reported-by: Patrick Schönthaler <patrick@notvads.ovh>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-21 10:46:42 -07:00
Willem de Bruijn
c6af0c227a ip: support SO_MARK cmsg
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 c7d39e3263
("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 351782067b ("ipv4: ipcm_cookie initializers").

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-13 21:44:19 +02:00
Eric Dumazet
d6fb396cfa ipv4: tcp: fix ACK/RST sent with a transmit delay
If we want to set a EDT time for the skb we want to send
via ip_send_unicast_reply(), we have to pass a new parameter
and initialize ipc.sockc.transmit_time with it.

This fixes the EDT time for ACK/RST packets sent on behalf of
a TIME_WAIT socket.

Fixes: a842fe1425 ("tcp: add optional per socket transmit delay")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-14 19:51:12 -07:00
David S. Miller
a6cdeeb16b Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Some ISDN files that got removed in net-next had some changes
done in mainline, take the removals.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-07 11:00:14 -07:00
Eric Dumazet
b703414675 net: fix use-after-free in kfree_skb_list
syzbot reported nasty use-after-free [1]

Lets remove frag_list field from structs ip_fraglist_iter
and ip6_fraglist_iter. This seens not needed anyway.

[1] :
BUG: KASAN: use-after-free in kfree_skb_list+0x5d/0x60 net/core/skbuff.c:706
Read of size 8 at addr ffff888085a3cbc0 by task syz-executor303/8947

CPU: 0 PID: 8947 Comm: syz-executor303 Not tainted 5.2.0-rc2+ #12
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+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:188
 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 kasan_report+0x12/0x20 mm/kasan/common.c:614
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 kfree_skb_list+0x5d/0x60 net/core/skbuff.c:706
 ip6_fragment+0x1ef4/0x2680 net/ipv6/ip6_output.c:882
 __ip6_finish_output+0x577/0xaa0 net/ipv6/ip6_output.c:144
 ip6_finish_output+0x38/0x1f0 net/ipv6/ip6_output.c:156
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x235/0x7f0 net/ipv6/ip6_output.c:179
 dst_output include/net/dst.h:433 [inline]
 ip6_local_out+0xbb/0x1b0 net/ipv6/output_core.c:179
 ip6_send_skb+0xbb/0x350 net/ipv6/ip6_output.c:1796
 ip6_push_pending_frames+0xc8/0xf0 net/ipv6/ip6_output.c:1816
 rawv6_push_pending_frames net/ipv6/raw.c:617 [inline]
 rawv6_sendmsg+0x2993/0x35e0 net/ipv6/raw.c:947
 inet_sendmsg+0x141/0x5d0 net/ipv4/af_inet.c:802
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:671
 ___sys_sendmsg+0x803/0x920 net/socket.c:2292
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2330
 __do_sys_sendmsg net/socket.c:2339 [inline]
 __se_sys_sendmsg net/socket.c:2337 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2337
 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x44add9
Code: e8 7c e6 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 1b 05 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f826f33bce8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000006e7a18 RCX: 000000000044add9
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000005
RBP: 00000000006e7a10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006e7a1c
R13: 00007ffcec4f7ebf R14: 00007f826f33c9c0 R15: 20c49ba5e353f7cf

Allocated by task 8947:
 save_stack+0x23/0x90 mm/kasan/common.c:71
 set_track mm/kasan/common.c:79 [inline]
 __kasan_kmalloc mm/kasan/common.c:489 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462
 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:497
 slab_post_alloc_hook mm/slab.h:437 [inline]
 slab_alloc_node mm/slab.c:3269 [inline]
 kmem_cache_alloc_node+0x131/0x710 mm/slab.c:3579
 __alloc_skb+0xd5/0x5e0 net/core/skbuff.c:199
 alloc_skb include/linux/skbuff.h:1058 [inline]
 __ip6_append_data.isra.0+0x2a24/0x3640 net/ipv6/ip6_output.c:1519
 ip6_append_data+0x1e5/0x320 net/ipv6/ip6_output.c:1688
 rawv6_sendmsg+0x1467/0x35e0 net/ipv6/raw.c:940
 inet_sendmsg+0x141/0x5d0 net/ipv4/af_inet.c:802
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:671
 ___sys_sendmsg+0x803/0x920 net/socket.c:2292
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2330
 __do_sys_sendmsg net/socket.c:2339 [inline]
 __se_sys_sendmsg net/socket.c:2337 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2337
 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 8947:
 save_stack+0x23/0x90 mm/kasan/common.c:71
 set_track mm/kasan/common.c:79 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459
 __cache_free mm/slab.c:3432 [inline]
 kmem_cache_free+0x86/0x260 mm/slab.c:3698
 kfree_skbmem net/core/skbuff.c:625 [inline]
 kfree_skbmem+0xc5/0x150 net/core/skbuff.c:619
 __kfree_skb net/core/skbuff.c:682 [inline]
 kfree_skb net/core/skbuff.c:699 [inline]
 kfree_skb+0xf0/0x390 net/core/skbuff.c:693
 kfree_skb_list+0x44/0x60 net/core/skbuff.c:708
 __dev_xmit_skb net/core/dev.c:3551 [inline]
 __dev_queue_xmit+0x3034/0x36b0 net/core/dev.c:3850
 dev_queue_xmit+0x18/0x20 net/core/dev.c:3914
 neigh_direct_output+0x16/0x20 net/core/neighbour.c:1532
 neigh_output include/net/neighbour.h:511 [inline]
 ip6_finish_output2+0x1034/0x2550 net/ipv6/ip6_output.c:120
 ip6_fragment+0x1ebb/0x2680 net/ipv6/ip6_output.c:863
 __ip6_finish_output+0x577/0xaa0 net/ipv6/ip6_output.c:144
 ip6_finish_output+0x38/0x1f0 net/ipv6/ip6_output.c:156
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x235/0x7f0 net/ipv6/ip6_output.c:179
 dst_output include/net/dst.h:433 [inline]
 ip6_local_out+0xbb/0x1b0 net/ipv6/output_core.c:179
 ip6_send_skb+0xbb/0x350 net/ipv6/ip6_output.c:1796
 ip6_push_pending_frames+0xc8/0xf0 net/ipv6/ip6_output.c:1816
 rawv6_push_pending_frames net/ipv6/raw.c:617 [inline]
 rawv6_sendmsg+0x2993/0x35e0 net/ipv6/raw.c:947
 inet_sendmsg+0x141/0x5d0 net/ipv4/af_inet.c:802
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:671
 ___sys_sendmsg+0x803/0x920 net/socket.c:2292
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2330
 __do_sys_sendmsg net/socket.c:2339 [inline]
 __se_sys_sendmsg net/socket.c:2337 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2337
 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888085a3cbc0
 which belongs to the cache skbuff_head_cache of size 224
The buggy address is located 0 bytes inside of
 224-byte region [ffff888085a3cbc0, ffff888085a3cca0)
The buggy address belongs to the page:
page:ffffea0002168f00 refcount:1 mapcount:0 mapping:ffff88821b6f63c0 index:0x0
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea00027bbf88 ffffea0002105b88 ffff88821b6f63c0
raw: 0000000000000000 ffff888085a3c080 000000010000000c 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888085a3ca80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888085a3cb00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
>ffff888085a3cb80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                           ^
 ffff888085a3cc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888085a3cc80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc

Fixes: 0feca6190f ("net: ipv6: add skbuff fraglist splitter")
Fixes: c8b17be0b7 ("net: ipv4: add skbuff fraglist splitter")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-03 15:18:00 -07:00
Pablo Neira Ayuso
065ff79f88 net: ipv4: split skbuff into fragments transformer
This patch exposes a new API to refragment a skbuff. This allows you to
split either a linear skbuff or to force the refragmentation of an
existing fraglist using a different mtu. The API consists of:

* ip_frag_init(), that initializes the internal state of the transformer.
* ip_frag_next(), that allows you to fetch the next fragment. This function
  internally allocates the skbuff that represents the fragment, it pushes
  the IPv4 header, and it also copies the payload for each fragment.

The ip_frag_state object stores the internal state of the splitter.

This code has been extracted from ip_do_fragment(). Symbols are also
exported to allow to reuse this iterator from the bridge codepath to
build its own refragmentation routine by reusing the existing codebase.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-30 14:18:17 -07:00
Pablo Neira Ayuso
c8b17be0b7 net: ipv4: add skbuff fraglist splitter
This patch adds the skbuff fraglist splitter. This API provides an
iterator to transform the fraglist into single skbuff objects, it
consists of:

* ip_fraglist_init(), that initializes the internal state of the
  fraglist splitter.
* ip_fraglist_prepare(), that restores the IPv4 header on the
  fragments.
* ip_fraglist_next(), that retrieves the fragment from the fraglist and
  it updates the internal state of the splitter to point to the next
  fragment skbuff in the fraglist.

The ip_fraglist_iter object stores the internal state of the iterator.

This code has been extracted from ip_do_fragment(). Symbols are also
exported to allow to reuse this iterator from the bridge codepath to
build its own refragmentation routine by reusing the existing codebase.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-30 14:18:17 -07:00