linux-stable.git/net/ipv6, branch v4.4.97

vti: fix use after free in vti_tunnel_xmit/vti6_tnl_xmit

2017-10-21T15:09:02+00:00

[ Upstream commit 36f6ee22d2d66046e369757ec6bbe1c482957ba6 ]

When running LTP IPsec tests, KASan might report:

BUG: KASAN: use-after-free in vti_tunnel_xmit+0xeee/0xff0 [ip_vti]
Read of size 4 at addr ffff880dc6ad1980 by task swapper/0/0
...
Call Trace:
  
  dump_stack+0x63/0x89
  print_address_description+0x7c/0x290
  kasan_report+0x28d/0x370
  ? vti_tunnel_xmit+0xeee/0xff0 [ip_vti]
  __asan_report_load4_noabort+0x19/0x20
  vti_tunnel_xmit+0xeee/0xff0 [ip_vti]
  ? vti_init_net+0x190/0x190 [ip_vti]
  ? save_stack_trace+0x1b/0x20
  ? save_stack+0x46/0xd0
  dev_hard_start_xmit+0x147/0x510
  ? icmp_echo.part.24+0x1f0/0x210
  __dev_queue_xmit+0x1394/0x1c60
...
Freed by task 0:
  save_stack_trace+0x1b/0x20
  save_stack+0x46/0xd0
  kasan_slab_free+0x70/0xc0
  kmem_cache_free+0x81/0x1e0
  kfree_skbmem+0xb1/0xe0
  kfree_skb+0x75/0x170
  kfree_skb_list+0x3e/0x60
  __dev_queue_xmit+0x1298/0x1c60
  dev_queue_xmit+0x10/0x20
  neigh_resolve_output+0x3a8/0x740
  ip_finish_output2+0x5c0/0xe70
  ip_finish_output+0x4ba/0x680
  ip_output+0x1c1/0x3a0
  xfrm_output_resume+0xc65/0x13d0
  xfrm_output+0x1e4/0x380
  xfrm4_output_finish+0x5c/0x70

Can be fixed if we get skb->len before dst_output().

Fixes: b9959fd3b0fa ("vti: switch to new ip tunnel code")
Fixes: 22e1b23dafa8 ("vti6: Support inter address family tunneling.")
Signed-off-by: Alexey Kodanev 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ip6_gre: skb_push ipv6hdr before packing the header in ip6gre_header

2017-10-21T15:09:02+00:00

[ Upstream commit 76cc0d3282d4b933fa144fa41fbc5318e0fdca24 ]

Now in ip6gre_header before packing the ipv6 header, it skb_push t->hlen
which only includes encap_hlen + tun_hlen. It means greh and inner header
would be over written by ipv6 stuff and ipv6h might have no chance to set
up.

Jianlin found this issue when using remote any on ip6_gre, the packets he
captured on gre dev are truncated:

22:50:26.210866 Out ethertype IPv6 (0x86dd), length 120: truncated-ip6 -\
8128 bytes missing!(flowlabel 0x92f40, hlim 0, next-header Options (0)  \
payload length: 8192) ::1:2000:0 > ::1:0:86dd: HBH [trunc] ip-proto-128 \
8184

It should also skb_push ipv6hdr so that ipv6h points to the right position
to set ipv6 stuff up.

This patch is to skb_push hlen + sizeof(*ipv6h) and also fix some indents
in ip6gre_header.

Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
Reported-by: Jianlin Shi 
Signed-off-by: Xin Long 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

udpv6: Fix the checksum computation when HW checksum does not apply

2017-10-21T15:09:02+00:00

[ Upstream commit 63ecc3d9436f8012e49dc846d6cb0a85a3433517 ]

While trying an ESP transport mode encryption for UDPv6 packets of
datagram size 1436 with MTU 1500, checksum error was observed in
the secondary fragment.

This error occurs due to the UDP payload checksum being missed out
when computing the full checksum for these packets in
udp6_hwcsum_outgoing().

Fixes: d39d938c8228 ("ipv6: Introduce udpv6_send_skb()")
Signed-off-by: Subash Abhinov Kasiviswanathan 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6: fix typo in fib6_net_exit()

2017-09-27T09:00:12+00:00

[ Upstream commit 32a805baf0fb70b6dbedefcd7249ac7f580f9e3b ]

IPv6 FIB should use FIB6_TABLE_HASHSZ, not FIB_TABLE_HASHSZ.

Fixes: ba1cc08d9488 ("ipv6: fix memory leak with multiple tables during netns destruction")
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6: fix memory leak with multiple tables during netns destruction

2017-09-27T09:00:11+00:00

[ Upstream commit ba1cc08d9488c94cb8d94f545305688b72a2a300 ]

fib6_net_exit only frees the main and local tables. If another table was
created with fib6_alloc_table, we leak it when the netns is destroyed.

Fix this in the same way ip_fib_net_exit cleans up tables, by walking
through the whole hashtable of fib6_table's. We can get rid of the
special cases for local and main, since they're also part of the
hashtable.

Reproducer:
    ip netns add x
    ip -net x -6 rule add from 6003:1::/64 table 100
    ip netns del x

Reported-by: Jianlin Shi 
Fixes: 58f09b78b730 ("[NETNS][IPV6] ip6_fib - make it per network namespace")
Signed-off-by: Sabrina Dubroca 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

Revert "net: fix percpu memory leaks"

2017-09-27T09:00:11+00:00

[ Upstream commit 5a63643e583b6a9789d7a225ae076fb4e603991c ]

This reverts commit 1d6119baf0610f813eb9d9580eb4fd16de5b4ceb.

After reverting commit 6d7b857d541e ("net: use lib/percpu_counter API
for fragmentation mem accounting") then here is no need for this
fix-up patch.  As percpu_counter is no longer used, it cannot
memory leak it any-longer.

Fixes: 6d7b857d541e ("net: use lib/percpu_counter API for fragmentation mem accounting")
Fixes: 1d6119baf061 ("net: fix percpu memory leaks")
Signed-off-by: Jesper Dangaard Brouer 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6: fix sparse warning on rt6i_node

2017-09-27T09:00:10+00:00

[ Upstream commit 4e587ea71bf924f7dac621f1351653bd41e446cb ]

Commit c5cff8561d2d adds rcu grace period before freeing fib6_node. This
generates a new sparse warning on rt->rt6i_node related code:
  net/ipv6/route.c:1394:30: error: incompatible types in comparison
  expression (different address spaces)
  ./include/net/ip6_fib.h:187:14: error: incompatible types in comparison
  expression (different address spaces)

This commit adds "__rcu" tag for rt6i_node and makes sure corresponding
rcu API is used for it.
After this fix, sparse no longer generates the above warning.

Fixes: c5cff8561d2d ("ipv6: add rcu grace period before freeing fib6_node")
Signed-off-by: Wei Wang 
Acked-by: Eric Dumazet 
Acked-by: Martin KaFai Lau 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6: add rcu grace period before freeing fib6_node

2017-09-27T09:00:10+00:00

[ Upstream commit c5cff8561d2d0006e972bd114afd51f082fee77c ]

We currently keep rt->rt6i_node pointing to the fib6_node for the route.
And some functions make use of this pointer to dereference the fib6_node
from rt structure, e.g. rt6_check(). However, as there is neither
refcount nor rcu taken when dereferencing rt->rt6i_node, it could
potentially cause crashes as rt->rt6i_node could be set to NULL by other
CPUs when doing a route deletion.
This patch introduces an rcu grace period before freeing fib6_node and
makes sure the functions that dereference it takes rcu_read_lock().

Note: there is no "Fixes" tag because this bug was there in a very
early stage.

Signed-off-by: Wei Wang 
Acked-by: Eric Dumazet 
Acked-by: Martin KaFai Lau 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6: accept 64k - 1 packet length in ip6_find_1stfragopt()

2017-09-27T09:00:10+00:00

[ Upstream commit 3de33e1ba0506723ab25734e098cf280ecc34756 ]

A packet length of exactly IPV6_MAXPLEN is allowed, we should
refuse parsing options only if the size is 64KiB or more.

While at it, remove one extra variable and one assignment which
were also introduced by the commit that introduced the size
check. Checking the sum 'offset + len' and only later adding
'len' to 'offset' doesn't provide any advantage over directly
summing to 'offset' and checking it.

Fixes: 6399f1fae4ec ("ipv6: avoid overflow of offset in ip6_find_1stfragopt")
Signed-off-by: Stefano Brivio 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6: repair fib6 tree in failure case

2017-08-30T08:19:20+00:00

[ Upstream commit 348a4002729ccab8b888b38cbc099efa2f2a2036 ]

In fib6_add(), it is possible that fib6_add_1() picks an intermediate
node and sets the node's fn->leaf to NULL in order to add this new
route. However, if fib6_add_rt2node() fails to add the new
route for some reason, fn->leaf will be left as NULL and could
potentially cause crash when fn->leaf is accessed in fib6_locate().
This patch makes sure fib6_repair_tree() is called to properly repair
fn->leaf in the above failure case.

Here is the syzkaller reported general protection fault in fib6_locate:
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Modules linked in:
CPU: 0 PID: 40937 Comm: syz-executor3 Not tainted
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d7d64100 ti: ffff8801d01a0000 task.ti: ffff8801d01a0000
RIP: 0010:[]  [] __ipv6_prefix_equal64_half include/net/ipv6.h:475 [inline]
RIP: 0010:[]  [] ipv6_prefix_equal include/net/ipv6.h:492 [inline]
RIP: 0010:[]  [] fib6_locate_1 net/ipv6/ip6_fib.c:1210 [inline]
RIP: 0010:[]  [] fib6_locate+0x281/0x3c0 net/ipv6/ip6_fib.c:1233
RSP: 0018:ffff8801d01a36a8  EFLAGS: 00010202
RAX: 0000000000000020 RBX: ffff8801bc790e00 RCX: ffffc90002983000
RDX: 0000000000001219 RSI: ffff8801d01a37a0 RDI: 0000000000000100
RBP: ffff8801d01a36f0 R08: 00000000000000ff R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000001
R13: dffffc0000000000 R14: ffff8801d01a37a0 R15: 0000000000000000
FS:  00007f6afd68c700(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004c6340 CR3: 00000000ba41f000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801d01a37a8 ffff8801d01a3780 ffffed003a0346f5 0000000c82a23ea0
 ffff8800b7bd7700 ffff8801d01a3780 ffff8800b6a1c940 ffffffff82a23ea0
 ffff8801d01a3920 ffff8801d01a3748 ffffffff82a223d6 ffff8801d7d64988
Call Trace:
 [] ip6_route_del+0x106/0x570 net/ipv6/route.c:2109
 [] inet6_rtm_delroute+0xfd/0x100 net/ipv6/route.c:3075
 [] rtnetlink_rcv_msg+0x549/0x7a0 net/core/rtnetlink.c:3450
 [] netlink_rcv_skb+0x141/0x370 net/netlink/af_netlink.c:2281
 [] rtnetlink_rcv+0x2f/0x40 net/core/rtnetlink.c:3456
 [] netlink_unicast_kernel net/netlink/af_netlink.c:1206 [inline]
 [] netlink_unicast+0x518/0x750 net/netlink/af_netlink.c:1232
 [] netlink_sendmsg+0x8ce/0xc30 net/netlink/af_netlink.c:1778
 [] sock_sendmsg_nosec net/socket.c:609 [inline]
 [] sock_sendmsg+0xcf/0x110 net/socket.c:619
 [] sock_write_iter+0x222/0x3a0 net/socket.c:834
 [] new_sync_write+0x1dd/0x2b0 fs/read_write.c:478
 [] __vfs_write+0xe4/0x110 fs/read_write.c:491
 [] vfs_write+0x178/0x4b0 fs/read_write.c:538
 [] SYSC_write fs/read_write.c:585 [inline]
 [] SyS_write+0xd9/0x1b0 fs/read_write.c:577
 [] entry_SYSCALL_64_fastpath+0x12/0x17

Note: there is no "Fixes" tag as this seems to be a bug introduced
very early.

Signed-off-by: Wei Wang 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman