6409 Commits

Author SHA1 Message Date
Paolo Abeni
2f73448041 udp: fix race between close() and udp_abort()
[ Upstream commit a8b897c7bcd47f4147d066e22cc01d1026d7640e ]

Kaustubh reported and diagnosed a panic in udp_lib_lookup().
The root cause is udp_abort() racing with close(). Both
racing functions acquire the socket lock, but udp{v6}_destroy_sock()
release it before performing destructive actions.

We can't easily extend the socket lock scope to avoid the race,
instead use the SOCK_DEAD flag to prevent udp_abort from doing
any action when the critical race happens.

Diagnosed-and-tested-by: Kaustubh Pandey <kapandey@codeaurora.org>
Fixes: 5d77dca82839 ("net: diag: support SOCK_DESTROY for UDP sockets")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-30 08:48:16 -04:00
Francesco Ruggeri
ea9ef822d5 ipv6: record frag_max_size in atomic fragments in input path
[ Upstream commit e29f011e8fc04b2cdc742a2b9bbfa1b62518381a ]

Commit dbd1759e6a9c ("ipv6: on reassembly, record frag_max_size")
filled the frag_max_size field in IP6CB in the input path.
The field should also be filled in case of atomic fragments.

Fixes: dbd1759e6a9c ('ipv6: on reassembly, record frag_max_size')
Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-03 08:38:12 +02:00
Taehee Yoo
4b77ad9097 mld: fix panic in mld_newpack()
[ Upstream commit 020ef930b826d21c5446fdc9db80fd72a791bc21 ]

mld_newpack() doesn't allow to allocate high order page,
only order-0 allocation is allowed.
If headroom size is too large, a kernel panic could occur in skb_put().

Test commands:
    ip netns del A
    ip netns del B
    ip netns add A
    ip netns add B
    ip link add veth0 type veth peer name veth1
    ip link set veth0 netns A
    ip link set veth1 netns B

    ip netns exec A ip link set lo up
    ip netns exec A ip link set veth0 up
    ip netns exec A ip -6 a a 2001:db8:0::1/64 dev veth0
    ip netns exec B ip link set lo up
    ip netns exec B ip link set veth1 up
    ip netns exec B ip -6 a a 2001:db8:0::2/64 dev veth1
    for i in {1..99}
    do
        let A=$i-1
        ip netns exec A ip link add ip6gre$i type ip6gre \
	local 2001:db8:$A::1 remote 2001:db8:$A::2 encaplimit 100
        ip netns exec A ip -6 a a 2001:db8:$i::1/64 dev ip6gre$i
        ip netns exec A ip link set ip6gre$i up

        ip netns exec B ip link add ip6gre$i type ip6gre \
	local 2001:db8:$A::2 remote 2001:db8:$A::1 encaplimit 100
        ip netns exec B ip -6 a a 2001:db8:$i::2/64 dev ip6gre$i
        ip netns exec B ip link set ip6gre$i up
    done

Splat looks like:
kernel BUG at net/core/skbuff.c:110!
invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
CPU: 0 PID: 7 Comm: kworker/0:1 Not tainted 5.12.0+ #891
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:skb_panic+0x15d/0x15f
Code: 92 fe 4c 8b 4c 24 10 53 8b 4d 70 45 89 e0 48 c7 c7 00 ae 79 83
41 57 41 56 41 55 48 8b 54 24 a6 26 f9 ff <0f> 0b 48 8b 6c 24 20 89
34 24 e8 4a 4e 92 fe 8b 34 24 48 c7 c1 20
RSP: 0018:ffff88810091f820 EFLAGS: 00010282
RAX: 0000000000000089 RBX: ffff8881086e9000 RCX: 0000000000000000
RDX: 0000000000000089 RSI: 0000000000000008 RDI: ffffed1020123efb
RBP: ffff888005f6eac0 R08: ffffed1022fc0031 R09: ffffed1022fc0031
R10: ffff888117e00187 R11: ffffed1022fc0030 R12: 0000000000000028
R13: ffff888008284eb0 R14: 0000000000000ed8 R15: 0000000000000ec0
FS:  0000000000000000(0000) GS:ffff888117c00000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8b801c5640 CR3: 0000000033c2c006 CR4: 00000000003706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ? ip6_mc_hdr.isra.26.constprop.46+0x12a/0x600
 ? ip6_mc_hdr.isra.26.constprop.46+0x12a/0x600
 skb_put.cold.104+0x22/0x22
 ip6_mc_hdr.isra.26.constprop.46+0x12a/0x600
 ? rcu_read_lock_sched_held+0x91/0xc0
 mld_newpack+0x398/0x8f0
 ? ip6_mc_hdr.isra.26.constprop.46+0x600/0x600
 ? lock_contended+0xc40/0xc40
 add_grhead.isra.33+0x280/0x380
 add_grec+0x5ca/0xff0
 ? mld_sendpack+0xf40/0xf40
 ? lock_downgrade+0x690/0x690
 mld_send_initial_cr.part.34+0xb9/0x180
 ipv6_mc_dad_complete+0x15d/0x1b0
 addrconf_dad_completed+0x8d2/0xbb0
 ? lock_downgrade+0x690/0x690
 ? addrconf_rs_timer+0x660/0x660
 ? addrconf_dad_work+0x73c/0x10e0
 addrconf_dad_work+0x73c/0x10e0

Allowing high order page allocation could fix this problem.

Fixes: 72e09ad107e7 ("ipv6: avoid high order allocations")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-03 08:38:11 +02:00
Eric Dumazet
867fd8d561 ipv6: remove extra dev_hold() for fallback tunnels
commit 0d7a7b2014b1a499a0fe24c9f3063d7856b5aaaf upstream.

My previous commits added a dev_hold() in tunnels ndo_init(),
but forgot to remove it from special functions setting up fallback tunnels.

Fallback tunnels do call their respective ndo_init()

This leads to various reports like :

unregister_netdevice: waiting for ip6gre0 to become free. Usage count = 2

Fixes: 48bb5697269a ("ip6_tunnel: sit: proper dev_{hold|put} in ndo_[un]init methods")
Fixes: 6289a98f0817 ("sit: proper dev_{hold|put} in ndo_[un]init methods")
Fixes: 40cb881b5aaa ("ip6_vti: proper dev_{hold|put} in ndo_[un]init methods")
Fixes: 7f700334be9a ("ip6_gre: proper dev_{hold|put} in ndo_[un]init methods")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:59:50 +02:00
Eric Dumazet
873d5de7f7 ip6_tunnel: sit: proper dev_{hold|put} in ndo_[un]init methods
commit 48bb5697269a7cbe5194dbb044dc38c517e34c58 upstream.

Same reasons than for the previous commits :
6289a98f0817 ("sit: proper dev_{hold|put} in ndo_[un]init methods")
40cb881b5aaa ("ip6_vti: proper dev_{hold|put} in ndo_[un]init methods")
7f700334be9a ("ip6_gre: proper dev_{hold|put} in ndo_[un]init methods")

After adopting CONFIG_PCPU_DEV_REFCNT=n option, syzbot was able to trigger
a warning [1]

Issue here is that:

- all dev_put() should be paired with a corresponding prior dev_hold().

- A driver doing a dev_put() in its ndo_uninit() MUST also
  do a dev_hold() in its ndo_init(), only when ndo_init()
  is returning 0.

Otherwise, register_netdevice() would call ndo_uninit()
in its error path and release a refcount too soon.

[1]
WARNING: CPU: 1 PID: 21059 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Modules linked in:
CPU: 1 PID: 21059 Comm: syz-executor.4 Not tainted 5.12.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Code: 1d 6a 5a e8 09 31 ff 89 de e8 8d 1a ab fd 84 db 75 e0 e8 d4 13 ab fd 48 c7 c7 a0 e1 c1 89 c6 05 4a 5a e8 09 01 e8 2e 36 fb 04 <0f> 0b eb c4 e8 b8 13 ab fd 0f b6 1d 39 5a e8 09 31 ff 89 de e8 58
RSP: 0018:ffffc900025aefe8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000040000 RSI: ffffffff815c51f5 RDI: fffff520004b5def
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815bdf8e R11: 0000000000000000 R12: ffff888023488568
R13: ffff8880254e9000 R14: 00000000dfd82cfd R15: ffff88802ee2d7c0
FS:  00007f13bc590700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0943e74000 CR3: 0000000025273000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __refcount_dec include/linux/refcount.h:344 [inline]
 refcount_dec include/linux/refcount.h:359 [inline]
 dev_put include/linux/netdevice.h:4135 [inline]
 ip6_tnl_dev_uninit+0x370/0x3d0 net/ipv6/ip6_tunnel.c:387
 register_netdevice+0xadf/0x1500 net/core/dev.c:10308
 ip6_tnl_create2+0x1b5/0x400 net/ipv6/ip6_tunnel.c:263
 ip6_tnl_newlink+0x312/0x580 net/ipv6/ip6_tunnel.c:2052
 __rtnl_newlink+0x1062/0x1710 net/core/rtnetlink.c:3443
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3491
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Fixes: 919067cc845f ("net: add CONFIG_PCPU_DEV_REFCNT")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:59:50 +02:00
Eric Dumazet
01cc9ab6fd sit: proper dev_{hold|put} in ndo_[un]init methods
commit 6289a98f0817a4a457750d6345e754838eae9439 upstream.

After adopting CONFIG_PCPU_DEV_REFCNT=n option, syzbot was able to trigger
a warning [1]

Issue here is that:

- all dev_put() should be paired with a corresponding prior dev_hold().

- A driver doing a dev_put() in its ndo_uninit() MUST also
  do a dev_hold() in its ndo_init(), only when ndo_init()
  is returning 0.

Otherwise, register_netdevice() would call ndo_uninit()
in its error path and release a refcount too soon.

Fixes: 919067cc845f ("net: add CONFIG_PCPU_DEV_REFCNT")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:59:50 +02:00
Eric Dumazet
2dc72d6a7f ip6_gre: proper dev_{hold|put} in ndo_[un]init methods
commit 7f700334be9aeb91d5d86ef9ad2d901b9b453e9b upstream.

After adopting CONFIG_PCPU_DEV_REFCNT=n option, syzbot was able to trigger
a warning [1]

Issue here is that:

- all dev_put() should be paired with a corresponding dev_hold(),
  and vice versa.

- A driver doing a dev_put() in its ndo_uninit() MUST also
  do a dev_hold() in its ndo_init(), only when ndo_init()
  is returning 0.

Otherwise, register_netdevice() would call ndo_uninit()
in its error path and release a refcount too soon.

ip6_gre for example (among others problematic drivers)
has to use dev_hold() in ip6gre_tunnel_init_common()
instead of from ip6gre_newlink_common(), covering
both ip6gre_tunnel_init() and ip6gre_tap_init()/

Note that ip6gre_tunnel_init_common() is not called from
ip6erspan_tap_init() thus we also need to add a dev_hold() there,
as ip6erspan_tunnel_uninit() does call dev_put()

[1]
refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 0 PID: 8422 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Modules linked in:
CPU: 1 PID: 8422 Comm: syz-executor854 Not tainted 5.12.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Code: 1d 6a 5a e8 09 31 ff 89 de e8 8d 1a ab fd 84 db 75 e0 e8 d4 13 ab fd 48 c7 c7 a0 e1 c1 89 c6 05 4a 5a e8 09 01 e8 2e 36 fb 04 <0f> 0b eb c4 e8 b8 13 ab fd 0f b6 1d 39 5a e8 09 31 ff 89 de e8 58
RSP: 0018:ffffc900018befd0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88801ef19c40 RSI: ffffffff815c51f5 RDI: fffff52000317dec
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815bdf8e R11: 0000000000000000 R12: ffff888018cf4568
R13: ffff888018cf4c00 R14: ffff8880228f2000 R15: ffffffff8d659b80
FS:  00000000014eb300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d7bf2b3138 CR3: 0000000014933000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __refcount_dec include/linux/refcount.h:344 [inline]
 refcount_dec include/linux/refcount.h:359 [inline]
 dev_put include/linux/netdevice.h:4135 [inline]
 ip6gre_tunnel_uninit+0x3d7/0x440 net/ipv6/ip6_gre.c:420
 register_netdevice+0xadf/0x1500 net/core/dev.c:10308
 ip6gre_newlink_common.constprop.0+0x158/0x410 net/ipv6/ip6_gre.c:1984
 ip6gre_newlink+0x275/0x7a0 net/ipv6/ip6_gre.c:2017
 __rtnl_newlink+0x1062/0x1710 net/core/rtnetlink.c:3443
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3491
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46

Fixes: 919067cc845f ("net: add CONFIG_PCPU_DEV_REFCNT")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:59:50 +02:00
Eric Dumazet
dd591526bc ip6_vti: proper dev_{hold|put} in ndo_[un]init methods
[ Upstream commit 40cb881b5aaa0b69a7d93dec8440d5c62dae299f ]

After adopting CONFIG_PCPU_DEV_REFCNT=n option, syzbot was able to trigger
a warning [1]

Issue here is that:

- all dev_put() should be paired with a corresponding prior dev_hold().

- A driver doing a dev_put() in its ndo_uninit() MUST also
  do a dev_hold() in its ndo_init(), only when ndo_init()
  is returning 0.

Otherwise, register_netdevice() would call ndo_uninit()
in its error path and release a refcount too soon.

Therefore, we need to move dev_hold() call from
vti6_tnl_create2() to vti6_dev_init_gen()

[1]
WARNING: CPU: 0 PID: 15951 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Modules linked in:
CPU: 0 PID: 15951 Comm: syz-executor.3 Not tainted 5.12.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Code: 1d 6a 5a e8 09 31 ff 89 de e8 8d 1a ab fd 84 db 75 e0 e8 d4 13 ab fd 48 c7 c7 a0 e1 c1 89 c6 05 4a 5a e8 09 01 e8 2e 36 fb 04 <0f> 0b eb c4 e8 b8 13 ab fd 0f b6 1d 39 5a e8 09 31 ff 89 de e8 58
RSP: 0018:ffffc90001eaef28 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000040000 RSI: ffffffff815c51f5 RDI: fffff520003d5dd7
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815bdf8e R11: 0000000000000000 R12: ffff88801bb1c568
R13: ffff88801f69e800 R14: 00000000ffffffff R15: ffff888050889d40
FS:  00007fc79314e700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1c1ff47108 CR3: 0000000020fd5000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __refcount_dec include/linux/refcount.h:344 [inline]
 refcount_dec include/linux/refcount.h:359 [inline]
 dev_put include/linux/netdevice.h:4135 [inline]
 vti6_dev_uninit+0x31a/0x360 net/ipv6/ip6_vti.c:297
 register_netdevice+0xadf/0x1500 net/core/dev.c:10308
 vti6_tnl_create2+0x1b5/0x400 net/ipv6/ip6_vti.c:190
 vti6_newlink+0x9d/0xd0 net/ipv6/ip6_vti.c:1020
 __rtnl_newlink+0x1062/0x1710 net/core/rtnetlink.c:3443
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3491
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 ____sys_sendmsg+0x331/0x810 net/socket.c:2350
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404
 __sys_sendmmsg+0x195/0x470 net/socket.c:2490
 __do_sys_sendmmsg net/socket.c:2519 [inline]
 __se_sys_sendmmsg net/socket.c:2516 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2516

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-22 10:59:40 +02:00
Hristo Venev
e4cb6ee364 net: ip6_tunnel: Unregister catch-all devices
commit 941ea91e87a6e879ed82dad4949f6234f2702bec upstream.

Similarly to the sit case, we need to remove the tunnels with no
addresses that have been moved to another network namespace.

Fixes: 0bd8762824e73 ("ip6tnl: add x-netns support")
Signed-off-by: Hristo Venev <hristo@venev.name>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-28 13:16:51 +02:00
Hristo Venev
67f33144cb net: sit: Unregister catch-all devices
commit 610f8c0fc8d46e0933955ce13af3d64484a4630a upstream.

A sit interface created without a local or a remote address is linked
into the `sit_net::tunnels_wc` list of its original namespace. When
deleting a network namespace, delete the devices that have been moved.

The following script triggers a null pointer dereference if devices
linked in a deleted `sit_net` remain:

    for i in `seq 1 30`; do
        ip netns add ns-test
        ip netns exec ns-test ip link add dev veth0 type veth peer veth1
        ip netns exec ns-test ip link add dev sit$i type sit dev veth0
        ip netns exec ns-test ip link set dev sit$i netns $$
        ip netns del ns-test
    done
    for i in `seq 1 30`; do
        ip link del dev sit$i
    done

Fixes: 5e6700b3bf98f ("sit: add support of x-netns")
Signed-off-by: Hristo Venev <hristo@venev.name>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-28 13:16:51 +02:00
Florian Westphal
12ec80252e netfilter: x_tables: fix compat match/target pad out-of-bound write
commit b29c457a6511435960115c0f548c4360d5f4801d upstream.

xt_compat_match/target_from_user doesn't check that zeroing the area
to start of next rule won't write past end of allocated ruleset blob.

Remove this code and zero the entire blob beforehand.

Reported-by: syzbot+cfc0247ac173f597aaaa@syzkaller.appspotmail.com
Reported-by: Andy Nguyen <theflow@google.com>
Fixes: 9fa492cdc160c ("[NETFILTER]: x_tables: simplify compat API")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-16 11:49:31 +02:00
Maciej Żenczykowski
ef99f18eb9 net-ipv6: bugfix - raw & sctp - switch to ipv6_can_nonlocal_bind()
commit 630e4576f83accf90366686f39808d665d8dbecc upstream.

Found by virtue of ipv6 raw sockets not honouring the per-socket
IP{,V6}_FREEBIND setting.

Based on hits found via:
  git grep '[.]ip_nonlocal_bind'
We fix both raw ipv6 sockets to honour IP{,V6}_FREEBIND and IP{,V6}_TRANSPARENT,
and we fix sctp sockets to honour IP{,V6}_TRANSPARENT (they already honoured
FREEBIND), and not just the ipv6 'ip_nonlocal_bind' sysctl.

The helper is defined as:
  static inline bool ipv6_can_nonlocal_bind(struct net *net, struct inet_sock *inet) {
    return net->ipv6.sysctl.ip_nonlocal_bind || inet->freebind || inet->transparent;
  }
so this change only widens the accepted opt-outs and is thus a clean bugfix.

I'm not entirely sure what 'fixes' tag to add, since this is AFAICT an ancient bug,
but IMHO this should be applied to stable kernels as far back as possible.
As such I'm adding a 'fixes' tag with the commit that originally added the helper,
which happened in 4.19.  Backporting to older LTS kernels (at least 4.9 and 4.14)
would presumably require open-coding it or backporting the helper as well.

Other possibly relevant commits:
  v4.18-rc6-1502-g83ba4645152d net: add helpers checking if socket can be bound to nonlocal address
  v4.18-rc6-1431-gd0c1f01138c4 net/ipv6: allow any source address for sendmsg pktinfo with ip_nonlocal_bind
  v4.14-rc5-271-gb71d21c274ef sctp: full support for ipv6 ip_nonlocal_bind & IP_FREEBIND
  v4.7-rc7-1883-g9b9742022888 sctp: support ipv6 nonlocal bind
  v4.1-12247-g35a256fee52c ipv6: Nonlocal bind

Cc: Lorenzo Colitti <lorenzo@google.com>
Fixes: 83ba4645152d ("net: add helpers checking if socket can be bound to nonlocal address")
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Reviewed-By: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14 08:22:33 +02:00
Muhammad Usama Anjum
426853f87e net: ipv6: check for validity before dereferencing cfg->fc_nlinfo.nlh
commit 864db232dc7036aa2de19749c3d5be0143b24f8f upstream.

nlh is being checked for validtity two times when it is dereferenced in
this function. Check for validity again when updating the flags through
nlh pointer to make the dereferencing safe.

CC: <stable@vger.kernel.org>
Addresses-Coverity: ("NULL pointer dereference")
Signed-off-by: Muhammad Usama Anjum <musamaanjum@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14 08:22:32 +02:00
Jakub Kicinski
1cf636535f ipv6: weaken the v4mapped source check
[ Upstream commit dcc32f4f183ab8479041b23a1525d48233df1d43 ]

This reverts commit 6af1799aaf3f1bc8defedddfa00df3192445bbf3.

Commit 6af1799aaf3f ("ipv6: drop incoming packets having a v4mapped
source address") introduced an input check against v4mapped addresses.
Use of such addresses on the wire is indeed questionable and not
allowed on public Internet. As the commit pointed out

  https://tools.ietf.org/html/draft-itojun-v6ops-v4mapped-harmful-02

lists potential issues.

Unfortunately there are applications which use v4mapped addresses,
and breaking them is a clear regression. For example v4mapped
addresses (or any semi-valid addresses, really) may be used
for uni-direction event streams or packet export.

Since the issue which sparked the addition of the check was with
TCP and request_socks in particular push the check down to TCPv6
and DCCP. This restores the ability to receive UDPv6 packets with
v4mapped address as the source.

Keep using the IPSTATS_MIB_INHDRERRORS statistic to minimize the
user-visible changes.

Fixes: 6af1799aaf3f ("ipv6: drop incoming packets having a v4mapped source address")
Reported-by: Sunyi Shao <sunyishao@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-07 12:48:47 +02:00
Mark Tomlinson
74bc0e5132 Revert "netfilter: x_tables: Update remaining dereference to RCU"
[ Upstream commit abe7034b9a8d57737e80cc16d60ed3666990bdbf ]

This reverts commit 443d6e86f821a165fae3fc3fc13086d27ac140b1.

This (and the following) patch basically re-implemented the RCU
mechanisms of patch 784544739a25. That patch was replaced because of the
performance problems that it created when replacing tables. Now, we have
the same issue: the call to synchronize_rcu() makes replacing tables
slower by as much as an order of magnitude.

Revert these patches and fix the issue in a different way.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:37:02 +02:00
Mark Tomlinson
0abcfaf058 Revert "netfilter: x_tables: Switch synchronization to RCU"
[ Upstream commit d3d40f237480abf3268956daf18cdc56edd32834 ]

This reverts commit cc00bcaa589914096edef7fb87ca5cee4a166b5c.

This (and the preceding) patch basically re-implemented the RCU
mechanisms of patch 784544739a25. That patch was replaced because of the
performance problems that it created when replacing tables. Now, we have
the same issue: the call to synchronize_rcu() makes replacing tables
slower by as much as an order of magnitude.

Prior to using RCU a script calling "iptables" approx. 200 times was
taking 1.16s. With RCU this increased to 11.59s.

Revert these patches and fix the issue in a different way.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:37:02 +02:00
Paul Moore
a44af1c697 cipso,calipso: resolve a number of problems with the DOI refcounts
commit ad5d07f4a9cd671233ae20983848874731102c08 upstream.

The current CIPSO and CALIPSO refcounting scheme for the DOI
definitions is a bit flawed in that we:

1. Don't correctly match gets/puts in netlbl_cipsov4_list().
2. Decrement the refcount on each attempt to remove the DOI from the
   DOI list, only removing it from the list once the refcount drops
   to zero.

This patch fixes these problems by adding the missing "puts" to
netlbl_cipsov4_list() and introduces a more conventional, i.e.
not-buggy, refcounting mechanism to the DOI definitions.  Upon the
addition of a DOI to the DOI list, it is initialized with a refcount
of one, removing a DOI from the list removes it from the list and
drops the refcount by one; "gets" and "puts" behave as expected with
respect to refcounts, increasing and decreasing the DOI's refcount by
one.

Fixes: b1edeb102397 ("netlabel: Replace protocol/NetLabel linking with refrerence counts")
Fixes: d7cce01504a0 ("netlabel: Add support for removing a CALIPSO DOI.")
Reported-by: syzbot+9ec037722d2603a9f52e@syzkaller.appspotmail.com
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 16:43:44 +01:00
Eric Dumazet
92ba49b27e tcp: annotate tp->write_seq lockless reads
[ Upstream commit 0f31746452e6793ad6271337438af8f4defb8940 ]

There are few places where we fetch tp->write_seq while
this field can change from IRQ or other cpu.

We need to add READ_ONCE() annotations, and also make
sure write sides use corresponding WRITE_ONCE() to avoid
store-tearing.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 16:43:43 +01:00
Eric Dumazet
7209e12096 tcp: annotate tp->copied_seq lockless reads
[ Upstream commit 7db48e983930285b765743ebd665aecf9850582b ]

There are few places where we fetch tp->copied_seq while
this field can change from IRQ or other cpu.

We need to add READ_ONCE() annotations, and also make
sure write sides use corresponding WRITE_ONCE() to avoid
store-tearing.

Note that tcp_inq_hint() was already using READ_ONCE(tp->copied_seq)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 16:43:42 +01:00
Jason A. Donenfeld
9efa1af186 net: icmp: pass zeroed opts from icmp{,v6}_ndo_send before sending
commit ee576c47db60432c37e54b1e2b43a8ca6d3a8dca upstream.

The icmp{,v6}_send functions make all sorts of use of skb->cb, casting
it with IPCB or IP6CB, assuming the skb to have come directly from the
inet layer. But when the packet comes from the ndo layer, especially
when forwarded, there's no telling what might be in skb->cb at that
point. As a result, the icmp sending code risks reading bogus memory
contents, which can result in nasty stack overflows such as this one
reported by a user:

    panic+0x108/0x2ea
    __stack_chk_fail+0x14/0x20
    __icmp_send+0x5bd/0x5c0
    icmp_ndo_send+0x148/0x160

In icmp_send, skb->cb is cast with IPCB and an ip_options struct is read
from it. The optlen parameter there is of particular note, as it can
induce writes beyond bounds. There are quite a few ways that can happen
in __ip_options_echo. For example:

    // sptr/skb are attacker-controlled skb bytes
    sptr = skb_network_header(skb);
    // dptr/dopt points to stack memory allocated by __icmp_send
    dptr = dopt->__data;
    // sopt is the corrupt skb->cb in question
    if (sopt->rr) {
        optlen  = sptr[sopt->rr+1]; // corrupt skb->cb + skb->data
        soffset = sptr[sopt->rr+2]; // corrupt skb->cb + skb->data
	// this now writes potentially attacker-controlled data, over
	// flowing the stack:
        memcpy(dptr, sptr+sopt->rr, optlen);
    }

In the icmpv6_send case, the story is similar, but not as dire, as only
IP6CB(skb)->iif and IP6CB(skb)->dsthao are used. The dsthao case is
worse than the iif case, but it is passed to ipv6_find_tlv, which does
a bit of bounds checking on the value.

This is easy to simulate by doing a `memset(skb->cb, 0x41,
sizeof(skb->cb));` before calling icmp{,v6}_ndo_send, and it's only by
good fortune and the rarity of icmp sending from that context that we've
avoided reports like this until now. For example, in KASAN:

    BUG: KASAN: stack-out-of-bounds in __ip_options_echo+0xa0e/0x12b0
    Write of size 38 at addr ffff888006f1f80e by task ping/89
    CPU: 2 PID: 89 Comm: ping Not tainted 5.10.0-rc7-debug+ #5
    Call Trace:
     dump_stack+0x9a/0xcc
     print_address_description.constprop.0+0x1a/0x160
     __kasan_report.cold+0x20/0x38
     kasan_report+0x32/0x40
     check_memory_region+0x145/0x1a0
     memcpy+0x39/0x60
     __ip_options_echo+0xa0e/0x12b0
     __icmp_send+0x744/0x1700

Actually, out of the 4 drivers that do this, only gtp zeroed the cb for
the v4 case, while the rest did not. So this commit actually removes the
gtp-specific zeroing, while putting the code where it belongs in the
shared infrastructure of icmp{,v6}_ndo_send.

This commit fixes the issue by passing an empty IPCB or IP6CB along to
the functions that actually do the work. For the icmp_send, this was
already trivial, thanks to __icmp_send providing the plumbing function.
For icmpv6_send, this required a tiny bit of refactoring to make it
behave like the v4 case, after which it was straight forward.

Fixes: a2b78e9b2cac ("sunvnet: generate ICMP PTMUD messages for smaller port MTUs")
Reported-by: SinYu <liuxyon@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/netdev/CAF=yD-LOF116aHub6RMe8vB8ZpnrrnoTdqhobEx+bvoA8AsP0w@mail.gmail.com/T/
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20210223131858.72082-1-Jason@zx2c4.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 09:39:59 +01:00
Eric Dumazet
00d3dc031d ipv6: icmp6: avoid indirect call for icmpv6_send()
commit cc7a21b6fbd945f8d8f61422ccd27203c1fafeb7 upstream.

If IPv6 is builtin, we do not need an expensive indirect call
to reach icmp6_send().

v2: put inline keyword before the type to avoid sparse warnings.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 09:39:59 +01:00
Jason A. Donenfeld
3efde1864a icmp: introduce helper for nat'd source address in network device context
commit 0b41713b606694257b90d61ba7e2712d8457648b upstream.

This introduces a helper function to be called only by network drivers
that wraps calls to icmp[v6]_send in a conntrack transformation, in case
NAT has been used. We don't want to pollute the non-driver path, though,
so we introduce this as a helper to be called by places that actually
make use of this, as suggested by Florian.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 09:39:58 +01:00
Matteo Croce
47d6a70043 ipv6: set multicast flag on the multicast route
commit ceed9038b2783d14e0422bdc6fd04f70580efb4c upstream.

The multicast route ff00::/8 is created with type RTN_UNICAST:

  $ ip -6 -d route
  unicast ::1 dev lo proto kernel scope global metric 256 pref medium
  unicast fe80::/64 dev eth0 proto kernel scope global metric 256 pref medium
  unicast ff00::/8 dev eth0 proto kernel scope global metric 256 pref medium

Set the type to RTN_MULTICAST which is more appropriate.

Fixes: e8478e80e5a7 ("net/ipv6: Save route type in rt6_info")
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27 11:05:43 +01:00
Matteo Croce
be33a52751 ipv6: create multicast route with RTPROT_KERNEL
commit a826b04303a40d52439aa141035fca5654ccaccd upstream.

The ff00::/8 multicast route is created without specifying the fc_protocol
field, so the default RTPROT_BOOT value is used:

  $ ip -6 -d route
  unicast ::1 dev lo proto kernel scope global metric 256 pref medium
  unicast fe80::/64 dev eth0 proto kernel scope global metric 256 pref medium
  unicast ff00::/8 dev eth0 proto boot scope global metric 256 pref medium

As the documentation says, this value identifies routes installed during
boot, but the route is created when interface is set up.
Change the value to RTPROT_KERNEL which is a better value.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27 11:05:43 +01:00
Aya Levin
394d9608da net: ipv6: Validate GSO SKB before finish IPv6 processing
[ Upstream commit b210de4f8c97d57de051e805686248ec4c6cfc52 ]

There are cases where GSO segment's length exceeds the egress MTU:
 - Forwarding of a TCP GRO skb, when DF flag is not set.
 - Forwarding of an skb that arrived on a virtualisation interface
   (virtio-net/vhost/tap) with TSO/GSO size set by other network
   stack.
 - Local GSO skb transmitted on an NETIF_F_TSO tunnel stacked over an
   interface with a smaller MTU.
 - Arriving GRO skb (or GSO skb in a virtualised environment) that is
   bridged to a NETIF_F_TSO tunnel stacked over an interface with an
   insufficient MTU.

If so:
 - Consume the SKB and its segments.
 - Issue an ICMP packet with 'Packet Too Big' message containing the
   MTU, allowing the source host to reduce its Path MTU appropriately.

Note: These cases are handled in the same manner in IPv4 output finish.
This patch aligns the behavior of IPv6 and the one of IPv4.

Fixes: 9e50849054a4 ("netfilter: ipv6: move POSTROUTING invocation before fragmentation")
Signed-off-by: Aya Levin <ayal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/r/1610027418-30438-1-git-send-email-ayal@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-23 15:49:57 +01:00
Jakub Kicinski
11e36dcef4 net: sit: unregister_netdevice on newlink's error path
[ Upstream commit 47e4bb147a96f1c9b4e7691e7e994e53838bfff8 ]

We need to unregister the netdevice if config failed.
.ndo_uninit takes care of most of the heavy lifting.

This was uncovered by recent commit c269a24ce057 ("net: make
free_netdev() more lenient with unregistering devices").
Previously the partially-initialized device would be left
in the system.

Reported-and-tested-by: syzbot+2393580080a2da190f04@syzkaller.appspotmail.com
Fixes: e2f1f072db8d ("sit: allow to configure 6rd tunnels via netlink")
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20210114012947.2515313-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-23 15:49:56 +01:00
Willem de Bruijn
d4ede0a453 esp: avoid unneeded kmap_atomic call
[ Upstream commit 9bd6b629c39e3fa9e14243a6d8820492be1a5b2e ]

esp(6)_output_head uses skb_page_frag_refill to allocate a buffer for
the esp trailer.

It accesses the page with kmap_atomic to handle highmem. But
skb_page_frag_refill can return compound pages, of which
kmap_atomic only maps the first underlying page.

skb_page_frag_refill does not return highmem, because flag
__GFP_HIGHMEM is not set. ESP uses it in the same manner as TCP.
That also does not call kmap_atomic, but directly uses page_address,
in skb_copy_to_page_nocache. Do the same for ESP.

This issue has become easier to trigger with recent kmap local
debugging feature CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP.

Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible")
Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-23 15:49:55 +01:00
Sean Tranchetti
8981235e1a net: ipv6: fib: flush exceptions when purging route
[ Upstream commit d8f5c29653c3f6995e8979be5623d263e92f6b86 ]

Route removal is handled by two code paths. The main removal path is via
fib6_del_route() which will handle purging any PMTU exceptions from the
cache, removing all per-cpu copies of the DST entry used by the route, and
releasing the fib6_info struct.

The second removal location is during fib6_add_rt2node() during a route
replacement operation. This path also calls fib6_purge_rt() to handle
cleaning up the per-cpu copies of the DST entries and releasing the
fib6_info associated with the older route, but it does not flush any PMTU
exceptions that the older route had. Since the older route is removed from
the tree during the replacement, we lose any way of accessing it again.

As these lingering DSTs and the fib6_info struct are holding references to
the underlying netdevice struct as well, unregistering that device from the
kernel can never complete.

Fixes: 2b760fcf5cfb3 ("ipv6: hook up exception table to store dst cache")
Signed-off-by: Sean Tranchetti <stranche@codeaurora.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/1609892546-11389-1-git-send-email-stranche@quicinc.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-17 14:04:19 +01:00
Subash Abhinov Kasiviswanathan
954cc63f5d netfilter: x_tables: Update remaining dereference to RCU
commit 443d6e86f821a165fae3fc3fc13086d27ac140b1 upstream.

This fixes the dereference to fetch the RCU pointer when holding
the appropriate xtables lock.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: cc00bcaa5899 ("netfilter: x_tables: Switch synchronization to RCU")
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-12 20:10:24 +01:00
Subash Abhinov Kasiviswanathan
98ab3ff5e7 netfilter: x_tables: Switch synchronization to RCU
[ Upstream commit cc00bcaa589914096edef7fb87ca5cee4a166b5c ]

When running concurrent iptables rules replacement with data, the per CPU
sequence count is checked after the assignment of the new information.
The sequence count is used to synchronize with the packet path without the
use of any explicit locking. If there are any packets in the packet path using
the table information, the sequence count is incremented to an odd value and
is incremented to an even after the packet process completion.

The new table value assignment is followed by a write memory barrier so every
CPU should see the latest value. If the packet path has started with the old
table information, the sequence counter will be odd and the iptables
replacement will wait till the sequence count is even prior to freeing the
old table info.

However, this assumes that the new table information assignment and the memory
barrier is actually executed prior to the counter check in the replacement
thread. If CPU decides to execute the assignment later as there is no user of
the table information prior to the sequence check, the packet path in another
CPU may use the old table information. The replacement thread would then free
the table information under it leading to a use after free in the packet
processing context-

Unable to handle kernel NULL pointer dereference at virtual
address 000000000000008e
pc : ip6t_do_table+0x5d0/0x89c
lr : ip6t_do_table+0x5b8/0x89c
ip6t_do_table+0x5d0/0x89c
ip6table_filter_hook+0x24/0x30
nf_hook_slow+0x84/0x120
ip6_input+0x74/0xe0
ip6_rcv_finish+0x7c/0x128
ipv6_rcv+0xac/0xe4
__netif_receive_skb+0x84/0x17c
process_backlog+0x15c/0x1b8
napi_poll+0x88/0x284
net_rx_action+0xbc/0x23c
__do_softirq+0x20c/0x48c

This could be fixed by forcing instruction order after the new table
information assignment or by switching to RCU for the synchronization.

Fixes: 80055dab5de0 ("netfilter: x_tables: make xt_replace_table wait until old rules are not used anymore")
Reported-by: Sean Tranchetti <stranche@codeaurora.org>
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:25:45 +01:00
Antoine Tenart
cf3d9717a5 net: ip6_gre: set dev->hard_header_len when using header_ops
[ Upstream commit 832ba596494b2c9eac7760259eff2d8b7dcad0ee ]

syzkaller managed to crash the kernel using an NBMA ip6gre interface. I
could reproduce it creating an NBMA ip6gre interface and forwarding
traffic to it:

  skbuff: skb_under_panic: text:ffffffff8250e927 len:148 put:44 head:ffff8c03c7a33
  ------------[ cut here ]------------
  kernel BUG at net/core/skbuff.c:109!
  Call Trace:
  skb_push+0x10/0x10
  ip6gre_header+0x47/0x1b0
  neigh_connected_output+0xae/0xf0

ip6gre tunnel provides its own header_ops->create, and sets it
conditionally when initializing the tunnel in NBMA mode. When
header_ops->create is used, dev->hard_header_len should reflect the
length of the header created. Otherwise, when not used,
dev->needed_headroom should be used.

Fixes: eb95f52fc72d ("net: ipv6_gre: Fix GRO to work on IPv6 over GRE tap")
Cc: Maria Pasechnik <mariap@mellanox.com>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Link: https://lore.kernel.org/r/20201130161911.464106-1-atenart@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-08 10:18:54 +01:00
Wang Hai
716cd2eba3 ipv6: addrlabel: fix possible memory leak in ip6addrlbl_net_init
[ Upstream commit e255e11e66da8281e337e4e352956e8a4999fca4 ]

kmemleak report a memory leak as follows:

unreferenced object 0xffff8880059c6a00 (size 64):
  comm "ip", pid 23696, jiffies 4296590183 (age 1755.384s)
  hex dump (first 32 bytes):
    20 01 00 10 00 00 00 00 00 00 00 00 00 00 00 00   ...............
    1c 00 00 00 00 00 00 00 00 00 00 00 07 00 00 00  ................
  backtrace:
    [<00000000aa4e7a87>] ip6addrlbl_add+0x90/0xbb0
    [<0000000070b8d7f1>] ip6addrlbl_net_init+0x109/0x170
    [<000000006a9ca9d4>] ops_init+0xa8/0x3c0
    [<000000002da57bf2>] setup_net+0x2de/0x7e0
    [<000000004e52d573>] copy_net_ns+0x27d/0x530
    [<00000000b07ae2b4>] create_new_namespaces+0x382/0xa30
    [<000000003b76d36f>] unshare_nsproxy_namespaces+0xa1/0x1d0
    [<0000000030653721>] ksys_unshare+0x3a4/0x780
    [<0000000007e82e40>] __x64_sys_unshare+0x2d/0x40
    [<0000000031a10c08>] do_syscall_64+0x33/0x40
    [<0000000099df30e7>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

We should free all rules when we catch an error in ip6addrlbl_net_init().
otherwise a memory leak will occur.

Fixes: 2a8cc6c89039 ("[IPV6] ADDRCONF: Support RFC3484 configurable address selection policy table.")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Link: https://lore.kernel.org/r/20201124071728.8385-1-wanghai38@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-08 10:18:51 +01:00
Zhang Changzhong
f8c18eab54 ah6: fix error return code in ah6_input()
[ Upstream commit a5ebcbdf34b65fcc07f38eaf2d60563b42619a59 ]

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Link: https://lore.kernel.org/r/1605581105-35295-1-git-send-email-zhangchangzhong@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-24 13:27:15 +01:00
Mao Wenan
bd73928fa9 net: Update window_clamp if SOCK_RCVBUF is set
[ Upstream commit 909172a149749242990a6e64cb55d55460d4e417 ]

When net.ipv4.tcp_syncookies=1 and syn flood is happened,
cookie_v4_check or cookie_v6_check tries to redo what
tcp_v4_send_synack or tcp_v6_send_synack did,
rsk_window_clamp will be changed if SOCK_RCVBUF is set,
which will make rcv_wscale is different, the client
still operates with initial window scale and can overshot
granted window, the client use the initial scale but local
server use new scale to advertise window value, and session
work abnormally.

Fixes: e88c64f0a425 ("tcp: allow effective reduction of TCP's rcv-buffer via setsockopt")
Signed-off-by: Mao Wenan <wenan.mao@linux.alibaba.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/1604967391-123737-1-git-send-email-wenan.mao@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-18 19:18:51 +01:00
Oliver Herms
7fe18ca043 IPv6: Set SIT tunnel hard_header_len to zero
[ Upstream commit 8ef9ba4d666614497a057d09b0a6eafc1e34eadf ]

Due to the legacy usage of hard_header_len for SIT tunnels while
already using infrastructure from net/ipv4/ip_tunnel.c the
calculation of the path MTU in tnl_update_pmtu is incorrect.
This leads to unnecessary creation of MTU exceptions for any
flow going over a SIT tunnel.

As SIT tunnels do not have a header themsevles other than their
transport (L3, L2) headers we're leaving hard_header_len set to zero
as tnl_update_pmtu is already taking care of the transport headers
sizes.

This will also help avoiding unnecessary IPv6 GC runs and spinlock
contention seen when using SIT tunnels and for more than
net.ipv6.route.gc_thresh flows.

Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.")
Signed-off-by: Oliver Herms <oliver.peter.herms@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20201103104133.GA1573211@tws
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-18 19:18:51 +01:00
Jason A. Donenfeld
580a117919 netfilter: use actual socket sk rather than skb sk when routing harder
commit 46d6c5ae953cc0be38efd0e469284df7c4328cf8 upstream.

If netfilter changes the packet mark when mangling, the packet is
rerouted using the route_me_harder set of functions. Prior to this
commit, there's one big difference between route_me_harder and the
ordinary initial routing functions, described in the comment above
__ip_queue_xmit():

   /* Note: skb->sk can be different from sk, in case of tunnels */
   int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,

That function goes on to correctly make use of sk->sk_bound_dev_if,
rather than skb->sk->sk_bound_dev_if. And indeed the comment is true: a
tunnel will receive a packet in ndo_start_xmit with an initial skb->sk.
It will make some transformations to that packet, and then it will send
the encapsulated packet out of a *new* socket. That new socket will
basically always have a different sk_bound_dev_if (otherwise there'd be
a routing loop). So for the purposes of routing the encapsulated packet,
the routing information as it pertains to the socket should come from
that socket's sk, rather than the packet's original skb->sk. For that
reason __ip_queue_xmit() and related functions all do the right thing.

One might argue that all tunnels should just call skb_orphan(skb) before
transmitting the encapsulated packet into the new socket. But tunnels do
*not* do this -- and this is wisely avoided in skb_scrub_packet() too --
because features like TSQ rely on skb->destructor() being called when
that buffer space is truely available again. Calling skb_orphan(skb) too
early would result in buffers filling up unnecessarily and accounting
info being all wrong. Instead, additional routing must take into account
the new sk, just as __ip_queue_xmit() notes.

So, this commit addresses the problem by fishing the correct sk out of
state->sk -- it's already set properly in the call to nf_hook() in
__ip_local_out(), which receives the sk as part of its normal
functionality. So we make sure to plumb state->sk through the various
route_me_harder functions, and then make correct use of it following the
example of __ip_queue_xmit().

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[Jason: backported to 4.19 from Sasha's 5.4 backport]
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-18 19:18:44 +01:00
Pablo Neira Ayuso
d74d61d90b netfilter: nf_log: missing vlan offload tag and proto
[ Upstream commit 0d9826bc18ce356e8909919ad681ad65d0a6061e ]

Dump vlan tag and proto for the usual vlan offload case if the
NF_LOG_MACDECODE flag is set on. Without this information the logging is
misleading as there is no reference to the VLAN header.

[12716.993704] test: IN=veth0 OUT= MACSRC=86:6c:92:ea:d6:73 MACDST=0e:3b:eb:86:73:76 VPROTO=8100 VID=10 MACPROTO=0800 SRC=192.168.10.2 DST=172.217.168.163 LEN=52 TOS=0x00 PREC=0x00 TTL=64 ID=2548 DF PROTO=TCP SPT=55848 DPT=80 WINDOW=501 RES=0x00 ACK FIN URGP=0
[12721.157643] test: IN=veth0 OUT= MACSRC=86:6c:92:ea:d6:73 MACDST=0e:3b:eb:86:73:76 VPROTO=8100 VID=10 MACPROTO=0806 ARP HTYPE=1 PTYPE=0x0800 OPCODE=2 MACSRC=86:6c:92:ea:d6:73 IPSRC=192.168.10.2 MACDST=0e:3b:eb:86:73:76 IPDST=192.168.10.1

Fixes: 83e96d443b37 ("netfilter: log: split family specific code to nf_log_{ip,ip6,common}.c files")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29 09:55:15 +01:00
Yonghong Song
6b00f0321c net: fix pos incrementment in ipv6_route_seq_next
[ Upstream commit 6617dfd440149e42ce4d2be615eb31a4755f4d30 ]

Commit 4fc427e05158 ("ipv6_route_seq_next should increase position index")
tried to fix the issue where seq_file pos is not increased
if a NULL element is returned with seq_ops->next(). See bug
  https://bugzilla.kernel.org/show_bug.cgi?id=206283
The commit effectively does:
  - increase pos for all seq_ops->start()
  - increase pos for all seq_ops->next()

For ipv6_route, increasing pos for all seq_ops->next() is correct.
But increasing pos for seq_ops->start() is not correct
since pos is used to determine how many items to skip during
seq_ops->start():
  iter->skip = *pos;
seq_ops->start() just fetches the *current* pos item.
The item can be skipped only after seq_ops->show() which essentially
is the beginning of seq_ops->next().

For example, I have 7 ipv6 route entries,
  root@arch-fb-vm1:~/net-next dd if=/proc/net/ipv6_route bs=4096
  00000000000000000000000000000000 40 00000000000000000000000000000000 00 00000000000000000000000000000000 00000400 00000001 00000000 00000001     eth0
  fe800000000000000000000000000000 40 00000000000000000000000000000000 00 00000000000000000000000000000000 00000100 00000001 00000000 00000001     eth0
  00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200       lo
  00000000000000000000000000000001 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000003 00000000 80200001       lo
  fe800000000000002050e3fffebd3be8 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000002 00000000 80200001     eth0
  ff000000000000000000000000000000 08 00000000000000000000000000000000 00 00000000000000000000000000000000 00000100 00000004 00000000 00000001     eth0
  00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200       lo
  0+1 records in
  0+1 records out
  1050 bytes (1.0 kB, 1.0 KiB) copied, 0.00707908 s, 148 kB/s
  root@arch-fb-vm1:~/net-next

In the above, I specify buffer size 4096, so all records can be returned
to user space with a single trip to the kernel.

If I use buffer size 128, since each record size is 149, internally
kernel seq_read() will read 149 into its internal buffer and return the data
to user space in two read() syscalls. Then user read() syscall will trigger
next seq_ops->start(). Since the current implementation increased pos even
for seq_ops->start(), it will skip record #2, #4 and #6, assuming the first
record is #1.

  root@arch-fb-vm1:~/net-next dd if=/proc/net/ipv6_route bs=128
  00000000000000000000000000000000 40 00000000000000000000000000000000 00 00000000000000000000000000000000 00000400 00000001 00000000 00000001     eth0
  00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200       lo
  fe800000000000002050e3fffebd3be8 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000002 00000000 80200001     eth0
  00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200       lo
4+1 records in
4+1 records out
600 bytes copied, 0.00127758 s, 470 kB/s

To fix the problem, create a fake pos pointer so seq_ops->start()
won't actually increase seq_file pos. With this fix, the
above `dd` command with `bs=128` will show correct result.

Fixes: 4fc427e05158 ("ipv6_route_seq_next should increase position index")
Cc: Alexei Starovoitov <ast@kernel.org>
Suggested-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-29 09:54:55 +01:00
Vasily Averin
24cb471708 ipv6_route_seq_next should increase position index
[ Upstream commit 4fc427e0515811250647d44de38d87d7b0e0790f ]

if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:14:29 +02:00
Necip Fazil Yildiran
fe91654256 net: ipv6: fix kconfig dependency warning for IPV6_SEG6_HMAC
[ Upstream commit db7cd91a4be15e1485d6b58c6afc8761c59c4efb ]

When IPV6_SEG6_HMAC is enabled and CRYPTO is disabled, it results in the
following Kbuild warning:

WARNING: unmet direct dependencies detected for CRYPTO_HMAC
  Depends on [n]: CRYPTO [=n]
  Selected by [y]:
  - IPV6_SEG6_HMAC [=y] && NET [=y] && INET [=y] && IPV6 [=y]

WARNING: unmet direct dependencies detected for CRYPTO_SHA1
  Depends on [n]: CRYPTO [=n]
  Selected by [y]:
  - IPV6_SEG6_HMAC [=y] && NET [=y] && INET [=y] && IPV6 [=y]

WARNING: unmet direct dependencies detected for CRYPTO_SHA256
  Depends on [n]: CRYPTO [=n]
  Selected by [y]:
  - IPV6_SEG6_HMAC [=y] && NET [=y] && INET [=y] && IPV6 [=y]

The reason is that IPV6_SEG6_HMAC selects CRYPTO_HMAC, CRYPTO_SHA1, and
CRYPTO_SHA256 without depending on or selecting CRYPTO while those configs
are subordinate to CRYPTO.

Honor the kconfig menu hierarchy to remove kconfig dependency warnings.

Fixes: bf355b8d2c30 ("ipv6: sr: add core files for SR HMAC support")
Signed-off-by: Necip Fazil Yildiran <fazilyildiran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-26 18:01:29 +02:00
Eric Dumazet
f2e5359dd3 ipv6: avoid lockdep issue in fib6_del()
[ Upstream commit 843d926b003ea692468c8cc5bea1f9f58dfa8c75 ]

syzbot reported twice a lockdep issue in fib6_del() [1]
which I think is caused by net->ipv6.fib6_null_entry
having a NULL fib6_table pointer.

fib6_del() already checks for fib6_null_entry special
case, we only need to return earlier.

Bug seems to occur very rarely, I have thus chosen
a 'bug origin' that makes backports not too complex.

[1]
WARNING: suspicious RCU usage
5.9.0-rc4-syzkaller #0 Not tainted
-----------------------------
net/ipv6/ip6_fib.c:1996 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
4 locks held by syz-executor.5/8095:
 #0: ffffffff8a7ea708 (rtnl_mutex){+.+.}-{3:3}, at: ppp_release+0x178/0x240 drivers/net/ppp/ppp_generic.c:401
 #1: ffff88804c422dd8 (&net->ipv6.fib6_gc_lock){+.-.}-{2:2}, at: spin_trylock_bh include/linux/spinlock.h:414 [inline]
 #1: ffff88804c422dd8 (&net->ipv6.fib6_gc_lock){+.-.}-{2:2}, at: fib6_run_gc+0x21b/0x2d0 net/ipv6/ip6_fib.c:2312
 #2: ffffffff89bd6a40 (rcu_read_lock){....}-{1:2}, at: __fib6_clean_all+0x0/0x290 net/ipv6/ip6_fib.c:2613
 #3: ffff8880a82e6430 (&tb->tb6_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:359 [inline]
 #3: ffff8880a82e6430 (&tb->tb6_lock){+.-.}-{2:2}, at: __fib6_clean_all+0x107/0x290 net/ipv6/ip6_fib.c:2245

stack backtrace:
CPU: 1 PID: 8095 Comm: syz-executor.5 Not tainted 5.9.0-rc4-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+0x198/0x1fd lib/dump_stack.c:118
 fib6_del+0x12b4/0x1630 net/ipv6/ip6_fib.c:1996
 fib6_clean_node+0x39b/0x570 net/ipv6/ip6_fib.c:2180
 fib6_walk_continue+0x4aa/0x8e0 net/ipv6/ip6_fib.c:2102
 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2150
 fib6_clean_tree+0xdb/0x120 net/ipv6/ip6_fib.c:2230
 __fib6_clean_all+0x120/0x290 net/ipv6/ip6_fib.c:2246
 fib6_clean_all net/ipv6/ip6_fib.c:2257 [inline]
 fib6_run_gc+0x113/0x2d0 net/ipv6/ip6_fib.c:2320
 ndisc_netdev_event+0x217/0x350 net/ipv6/ndisc.c:1805
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2033
 call_netdevice_notifiers_extack net/core/dev.c:2045 [inline]
 call_netdevice_notifiers net/core/dev.c:2059 [inline]
 dev_close_many+0x30b/0x650 net/core/dev.c:1634
 rollback_registered_many+0x3a8/0x1210 net/core/dev.c:9261
 rollback_registered net/core/dev.c:9329 [inline]
 unregister_netdevice_queue+0x2dd/0x570 net/core/dev.c:10410
 unregister_netdevice include/linux/netdevice.h:2774 [inline]
 ppp_release+0x216/0x240 drivers/net/ppp/ppp_generic.c:403
 __fput+0x285/0x920 fs/file_table.c:281
 task_work_run+0xdd/0x190 kernel/task_work.c:141
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:163 [inline]
 exit_to_user_mode_prepare+0x1e1/0x200 kernel/entry/common.c:190
 syscall_exit_to_user_mode+0x7e/0x2e0 kernel/entry/common.c:265
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 421842edeaf6 ("net/ipv6: Add fib6_null_entry")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: David Ahern <dsahern@gmail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-26 18:01:29 +02:00
Mark Tomlinson
c3f242a608 gre6: Fix reception with IP6_TNL_F_RCV_DSCP_COPY
[ Upstream commit 272502fcb7cda01ab07fc2fcff82d1d2f73d43cc ]

When receiving an IPv4 packet inside an IPv6 GRE packet, and the
IP6_TNL_F_RCV_DSCP_COPY flag is set on the tunnel, the IPv4 header would
get corrupted. This is due to the common ip6_tnl_rcv() function assuming
that the inner header is always IPv6. This patch checks the tunnel
protocol for IPv4 inner packets, but still defaults to IPv6.

Fixes: 308edfdf1563 ("gre6: Cleanup GREv6 receive path, call common GRE functions")
Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03 11:24:17 +02:00
Cong Wang
9c8652db5c ipv6: fix memory leaks on IPV6_ADDRFORM path
[ Upstream commit 8c0de6e96c9794cb523a516c465991a70245da1c ]

IPV6_ADDRFORM causes resource leaks when converting an IPv6 socket
to IPv4, particularly struct ipv6_ac_socklist. Similar to
struct ipv6_mc_socklist, we should just close it on this path.

This bug can be easily reproduced with the following C program:

  #include <stdio.h>
  #include <string.h>
  #include <sys/types.h>
  #include <sys/socket.h>
  #include <arpa/inet.h>

  int main()
  {
    int s, value;
    struct sockaddr_in6 addr;
    struct ipv6_mreq m6;

    s = socket(AF_INET6, SOCK_DGRAM, 0);
    addr.sin6_family = AF_INET6;
    addr.sin6_port = htons(5000);
    inet_pton(AF_INET6, "::ffff:192.168.122.194", &addr.sin6_addr);
    connect(s, (struct sockaddr *)&addr, sizeof(addr));

    inet_pton(AF_INET6, "fe80::AAAA", &m6.ipv6mr_multiaddr);
    m6.ipv6mr_interface = 5;
    setsockopt(s, SOL_IPV6, IPV6_JOIN_ANYCAST, &m6, sizeof(m6));

    value = AF_INET;
    setsockopt(s, SOL_IPV6, IPV6_ADDRFORM, &value, sizeof(value));

    close(s);
    return 0;
  }

Reported-by: ch3332xr@gmail.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-11 15:32:34 +02:00
Kuniyuki Iwashima
325ac51bee udp: Improve load balancing for SO_REUSEPORT.
[ Upstream commit efc6b6f6c3113e8b203b9debfb72d81e0f3dcace ]

Currently, SO_REUSEPORT does not work well if connected sockets are in a
UDP reuseport group.

Then reuseport_has_conns() returns true and the result of
reuseport_select_sock() is discarded. Also, unconnected sockets have the
same score, hence only does the first unconnected socket in udp_hslot
always receive all packets sent to unconnected sockets.

So, the result of reuseport_select_sock() should be used for load
balancing.

The noteworthy point is that the unconnected sockets placed after
connected sockets in sock_reuseport.socks will receive more packets than
others because of the algorithm in reuseport_select_sock().

    index | connected | reciprocal_scale | result
    ---------------------------------------------
    0     | no        | 20%              | 40%
    1     | no        | 20%              | 20%
    2     | yes       | 20%              | 0%
    3     | no        | 20%              | 40%
    4     | yes       | 20%              | 0%

If most of the sockets are connected, this can be a problem, but it still
works better than now.

Fixes: acdcecc61285 ("udp: correct reuseport selection with connected sockets")
CC: Willem de Bruijn <willemb@google.com>
Reviewed-by: Benjamin Herrenschmidt <benh@amazon.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-31 18:37:49 +02:00
Miaohe Lin
9c6d57298e net: udp: Fix wrong clean up for IS_UDPLITE macro
[ Upstream commit b0a422772fec29811e293c7c0e6f991c0fd9241d ]

We can't use IS_UDPLITE to replace udp_sk->pcflag when UDPLITE_RECV_CC is
checked.

Fixes: b2bf1e2659b1 ("[UDP]: Clean up for IS_UDPLITE macro")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-31 18:37:48 +02:00
Wei Yongjun
abcf95e000 ip6_gre: fix null-ptr-deref in ip6gre_init_net()
[ Upstream commit 46ef5b89ec0ecf290d74c4aee844f063933c4da4 ]

KASAN report null-ptr-deref error when register_netdev() failed:

KASAN: null-ptr-deref in range [0x00000000000003c0-0x00000000000003c7]
CPU: 2 PID: 422 Comm: ip Not tainted 5.8.0-rc4+ #12
Call Trace:
 ip6gre_init_net+0x4ab/0x580
 ? ip6gre_tunnel_uninit+0x3f0/0x3f0
 ops_init+0xa8/0x3c0
 setup_net+0x2de/0x7e0
 ? rcu_read_lock_bh_held+0xb0/0xb0
 ? ops_init+0x3c0/0x3c0
 ? kasan_unpoison_shadow+0x33/0x40
 ? __kasan_kmalloc.constprop.0+0xc2/0xd0
 copy_net_ns+0x27d/0x530
 create_new_namespaces+0x382/0xa30
 unshare_nsproxy_namespaces+0xa1/0x1d0
 ksys_unshare+0x39c/0x780
 ? walk_process_tree+0x2a0/0x2a0
 ? trace_hardirqs_on+0x4a/0x1b0
 ? _raw_spin_unlock_irq+0x1f/0x30
 ? syscall_trace_enter+0x1a7/0x330
 ? do_syscall_64+0x1c/0xa0
 __x64_sys_unshare+0x2d/0x40
 do_syscall_64+0x56/0xa0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

ip6gre_tunnel_uninit() has set 'ign->fb_tunnel_dev' to NULL, later
access to ign->fb_tunnel_dev cause null-ptr-deref. Fix it by saving
'ign->fb_tunnel_dev' to local variable ndev.

Fixes: dafabb6590cb ("ip6_gre: fix use-after-free in ip6gre_tunnel_lookup()")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-31 18:37:47 +02:00
Taehee Yoo
a611d1a063 ip6_gre: fix use-after-free in ip6gre_tunnel_lookup()
[ Upstream commit dafabb6590cb15f300b77c095d50312e2c7c8e0f ]

In the datapath, the ip6gre_tunnel_lookup() is used and it internally uses
fallback tunnel device pointer, which is fb_tunnel_dev.
This pointer variable should be set to NULL when a fb interface is deleted.
But there is no routine to set fb_tunnel_dev pointer to NULL.
So, this pointer will be still used after interface is deleted and
it eventually results in the use-after-free problem.

Test commands:
    ip netns add A
    ip netns add B
    ip link add eth0 type veth peer name eth1
    ip link set eth0 netns A
    ip link set eth1 netns B

    ip netns exec A ip link set lo up
    ip netns exec A ip link set eth0 up
    ip netns exec A ip link add ip6gre1 type ip6gre local fc:0::1 \
	    remote fc:0::2
    ip netns exec A ip -6 a a fc💯:1/64 dev ip6gre1
    ip netns exec A ip link set ip6gre1 up
    ip netns exec A ip -6 a a fc:0::1/64 dev eth0
    ip netns exec A ip link set ip6gre0 up

    ip netns exec B ip link set lo up
    ip netns exec B ip link set eth1 up
    ip netns exec B ip link add ip6gre1 type ip6gre local fc:0::2 \
	    remote fc:0::1
    ip netns exec B ip -6 a a fc💯:2/64 dev ip6gre1
    ip netns exec B ip link set ip6gre1 up
    ip netns exec B ip -6 a a fc:0::2/64 dev eth1
    ip netns exec B ip link set ip6gre0 up
    ip netns exec A ping fc💯:2 -s 60000 &
    ip netns del B

Splat looks like:
[   73.087285][    C1] BUG: KASAN: use-after-free in ip6gre_tunnel_lookup+0x1064/0x13f0 [ip6_gre]
[   73.088361][    C1] Read of size 4 at addr ffff888040559218 by task ping/1429
[   73.089317][    C1]
[   73.089638][    C1] CPU: 1 PID: 1429 Comm: ping Not tainted 5.7.0+ #602
[   73.090531][    C1] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   73.091725][    C1] Call Trace:
[   73.092160][    C1]  <IRQ>
[   73.092556][    C1]  dump_stack+0x96/0xdb
[   73.093122][    C1]  print_address_description.constprop.6+0x2cc/0x450
[   73.094016][    C1]  ? ip6gre_tunnel_lookup+0x1064/0x13f0 [ip6_gre]
[   73.094894][    C1]  ? ip6gre_tunnel_lookup+0x1064/0x13f0 [ip6_gre]
[   73.095767][    C1]  ? ip6gre_tunnel_lookup+0x1064/0x13f0 [ip6_gre]
[   73.096619][    C1]  kasan_report+0x154/0x190
[   73.097209][    C1]  ? ip6gre_tunnel_lookup+0x1064/0x13f0 [ip6_gre]
[   73.097989][    C1]  ip6gre_tunnel_lookup+0x1064/0x13f0 [ip6_gre]
[   73.098750][    C1]  ? gre_del_protocol+0x60/0x60 [gre]
[   73.099500][    C1]  gre_rcv+0x1c5/0x1450 [ip6_gre]
[   73.100199][    C1]  ? ip6gre_header+0xf00/0xf00 [ip6_gre]
[   73.100985][    C1]  ? rcu_read_lock_sched_held+0xc0/0xc0
[   73.101830][    C1]  ? ip6_input_finish+0x5/0xf0
[   73.102483][    C1]  ip6_protocol_deliver_rcu+0xcbb/0x1510
[   73.103296][    C1]  ip6_input_finish+0x5b/0xf0
[   73.103920][    C1]  ip6_input+0xcd/0x2c0
[   73.104473][    C1]  ? ip6_input_finish+0xf0/0xf0
[   73.105115][    C1]  ? rcu_read_lock_held+0x90/0xa0
[   73.105783][    C1]  ? rcu_read_lock_sched_held+0xc0/0xc0
[   73.106548][    C1]  ipv6_rcv+0x1f1/0x300
[ ... ]

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-30 23:17:05 -04:00
Wang Hai
cf418c02c7 mld: fix memory leak in ipv6_mc_destroy_dev()
[ Upstream commit ea2fce88d2fd678ed9d45354ff49b73f1d5615dd ]

Commit a84d01647989 ("mld: fix memory leak in mld_del_delrec()") fixed
the memory leak of MLD, but missing the ipv6_mc_destroy_dev() path, in
which mca_sources are leaked after ma_put().

Using ip6_mc_clear_src() to take care of the missing free.

BUG: memory leak
unreferenced object 0xffff8881113d3180 (size 64):
  comm "syz-executor071", pid 389, jiffies 4294887985 (age 17.943s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 ff 02 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<000000002cbc483c>] kmalloc include/linux/slab.h:555 [inline]
    [<000000002cbc483c>] kzalloc include/linux/slab.h:669 [inline]
    [<000000002cbc483c>] ip6_mc_add1_src net/ipv6/mcast.c:2237 [inline]
    [<000000002cbc483c>] ip6_mc_add_src+0x7f5/0xbb0 net/ipv6/mcast.c:2357
    [<0000000058b8b1ff>] ip6_mc_source+0xe0c/0x1530 net/ipv6/mcast.c:449
    [<000000000bfc4fb5>] do_ipv6_setsockopt.isra.12+0x1b2c/0x3b30 net/ipv6/ipv6_sockglue.c:754
    [<00000000e4e7a722>] ipv6_setsockopt+0xda/0x150 net/ipv6/ipv6_sockglue.c:950
    [<0000000029260d9a>] rawv6_setsockopt+0x45/0x100 net/ipv6/raw.c:1081
    [<000000005c1b46f9>] __sys_setsockopt+0x131/0x210 net/socket.c:2132
    [<000000008491f7db>] __do_sys_setsockopt net/socket.c:2148 [inline]
    [<000000008491f7db>] __se_sys_setsockopt net/socket.c:2145 [inline]
    [<000000008491f7db>] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2145
    [<00000000c7bc11c5>] do_syscall_64+0xa1/0x530 arch/x86/entry/common.c:295
    [<000000005fb7a3f3>] entry_SYSCALL_64_after_hwframe+0x49/0xb3

Fixes: 1666d49e1d41 ("mld: do not remove mld souce list info when set link down")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Acked-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-30 23:17:03 -04:00
Hangbin Liu
470e709f63 ipv6: fix IPV6_ADDRFORM operation logic
[ Upstream commit 79a1f0ccdbb4ad700590f61b00525b390cb53905 ]

Socket option IPV6_ADDRFORM supports UDP/UDPLITE and TCP at present.
Previously the checking logic looks like:
if (sk->sk_protocol == IPPROTO_UDP || sk->sk_protocol == IPPROTO_UDPLITE)
	do_some_check;
else if (sk->sk_protocol != IPPROTO_TCP)
	break;

After commit b6f6118901d1 ("ipv6: restrict IPV6_ADDRFORM operation"), TCP
was blocked as the logic changed to:
if (sk->sk_protocol == IPPROTO_UDP || sk->sk_protocol == IPPROTO_UDPLITE)
	do_some_check;
else if (sk->sk_protocol == IPPROTO_TCP)
	do_some_check;
	break;
else
	break;

Then after commit 82c9ae440857 ("ipv6: fix restrict IPV6_ADDRFORM operation")
UDP/UDPLITE were blocked as the logic changed to:
if (sk->sk_protocol == IPPROTO_UDP || sk->sk_protocol == IPPROTO_UDPLITE)
	do_some_check;
if (sk->sk_protocol == IPPROTO_TCP)
	do_some_check;

if (sk->sk_protocol != IPPROTO_TCP)
	break;

Fix it by using Eric's code and simply remove the break in TCP check, which
looks like:
if (sk->sk_protocol == IPPROTO_UDP || sk->sk_protocol == IPPROTO_UDPLITE)
	do_some_check;
else if (sk->sk_protocol == IPPROTO_TCP)
	do_some_check;
else
	break;

Fixes: 82c9ae440857 ("ipv6: fix restrict IPV6_ADDRFORM operation")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-22 09:04:58 +02:00
Xin Long
e8f7bd7b3c esp6: get the right proto for transport mode in esp6_gso_encap
commit 3c96ec56828922e3fe5477f75eb3fc02f98f98b5 upstream.

For transport mode, when ipv6 nexthdr is set, the packet format might
be like:

    ----------------------------------------------------
    |        | dest |     |     |      |  ESP    | ESP |
    | IP6 hdr| opts.| ESP | TCP | Data | Trailer | ICV |
    ----------------------------------------------------

What it wants to get for x-proto in esp6_gso_encap() is the proto that
will be set in ESP nexthdr. So it should skip all ipv6 nexthdrs and
get the real transport protocol. Othersize, the wrong proto number
will be set into ESP nexthdr.

This patch is to skip all ipv6 nexthdrs by calling ipv6_skip_exthdr()
in esp6_gso_encap().

Fixes: 7862b4058b9f ("esp: Add gso handlers for esp4 and esp6")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03 08:19:48 +02:00