linux.git/net/dccp/ipv6.c, branch v6.3

dccp/tcp: Avoid negative sk_forward_alloc by ipv6_pinfo.pktoptions.

2023-02-11T03:53:42+00:00

Eric Dumazet pointed out [0] that when we call skb_set_owner_r()
for ipv6_pinfo.pktoptions, sk_rmem_schedule() has not been called,
resulting in a negative sk_forward_alloc.

We add a new helper which clones a skb and sets its owner only
when sk_rmem_schedule() succeeds.

Note that we move skb_set_owner_r() forward in (dccp|tcp)_v6_do_rcv()
because tcp_send_synack() can make sk_forward_alloc negative before
ipv6_opt_accepted() in the crossed SYN-ACK or self-connect() cases.

[0]: https://lore.kernel.org/netdev/CANn89iK9oc20Jdi_41jb9URdF210r7d1Y-+uypbMSbOfY6jqrg@mail.gmail.com/

Fixes: 323fbd0edf3f ("net: dccp: Add handling of IPV6_PKTOPTIONS to dccp_v6_do_rcv()")
Fixes: 3df80d9320bc ("[DCCP]: Introduce DCCPv6")
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: Eric Dumazet 
Signed-off-by: Jakub Kicinski

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

2022-11-29T21:04:52+00:00

tools/lib/bpf/ringbuf.c
  927cbb478adf ("libbpf: Handle size overflow for ringbuf mmap")
  b486d19a0ab0 ("libbpf: checkpatch: Fixed code alignments in ringbuf.c")
https://lore.kernel.org/all/20221121122707.44d1446a@canb.auug.org.au/

Signed-off-by: Jakub Kicinski

dccp/tcp: Fixup bhash2 bucket when connect() fails.

2022-11-23T04:15:37+00:00

If a socket bound to a wildcard address fails to connect(), we
only reset saddr and keep the port.  Then, we have to fix up the
bhash2 bucket; otherwise, the bucket has an inconsistent address
in the list.

Also, listen() for such a socket will fire the WARN_ON() in
inet_csk_get_port(). [0]

Note that when a system runs out of memory, we give up fixing the
bucket and unlink sk from bhash and bhash2 by inet_put_port().

[0]:
WARNING: CPU: 0 PID: 207 at net/ipv4/inet_connection_sock.c:548 inet_csk_get_port (net/ipv4/inet_connection_sock.c:548 (discriminator 1))
Modules linked in:
CPU: 0 PID: 207 Comm: bhash2_prev_rep Not tainted 6.1.0-rc3-00799-gc8421681c845 #63
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.amzn2022.0.1 04/01/2014
RIP: 0010:inet_csk_get_port (net/ipv4/inet_connection_sock.c:548 (discriminator 1))
Code: 74 a7 eb 93 48 8b 54 24 18 0f b7 cb 4c 89 e6 4c 89 ff e8 48 b2 ff ff 49 8b 87 18 04 00 00 e9 32 ff ff ff 0f 0b e9 34 ff ff ff <0f> 0b e9 42 ff ff ff 41 8b 7f 50 41 8b 4f 54 89 fe 81 f6 00 00 ff
RSP: 0018:ffffc900003d7e50 EFLAGS: 00010202
RAX: ffff8881047fb500 RBX: 0000000000004e20 RCX: 0000000000000000
RDX: 000000000000000a RSI: 00000000fffffe00 RDI: 00000000ffffffff
RBP: ffffffff8324dc00 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000004e20 R15: ffff8881054e1280
FS:  00007f8ac04dc740(0000) GS:ffff88842fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020001540 CR3: 00000001055fa003 CR4: 0000000000770ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 
 inet_csk_listen_start (net/ipv4/inet_connection_sock.c:1205)
 inet_listen (net/ipv4/af_inet.c:228)
 __sys_listen (net/socket.c:1810)
 __x64_sys_listen (net/socket.c:1819 net/socket.c:1817 net/socket.c:1817)
 do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
 entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
RIP: 0033:0x7f8ac051de5d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 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 73 01 c3 48 8b 0d 93 af 1b 00 f7 d8 64 89 01 48
RSP: 002b:00007ffc1c177248 EFLAGS: 00000206 ORIG_RAX: 0000000000000032
RAX: ffffffffffffffda RBX: 0000000020001550 RCX: 00007f8ac051de5d
RDX: ffffffffffffff80 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007ffc1c177270 R08: 0000000000000018 R09: 0000000000000007
R10: 0000000020001540 R11: 0000000000000206 R12: 00007ffc1c177388
R13: 0000000000401169 R14: 0000000000403e18 R15: 00007f8ac0723000
 

Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address")
Reported-by: syzbot 
Reported-by: Mat Martineau 
Signed-off-by: Kuniyuki Iwashima 
Acked-by: Joanne Koong 
Reviewed-by: Eric Dumazet 
Signed-off-by: Jakub Kicinski

dccp/tcp: Update saddr under bhash's lock.

2022-11-23T04:15:36+00:00

When we call connect() for a socket bound to a wildcard address, we update
saddr locklessly.  However, it could result in a data race; another thread
iterating over bhash might see a corrupted address.

Let's update saddr under the bhash bucket's lock.

Fixes: 3df80d9320bc ("[DCCP]: Introduce DCCPv6")
Fixes: 7c657876b63c ("[DCCP]: Initial implementation")
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima 
Acked-by: Joanne Koong 
Reviewed-by: Eric Dumazet 
Signed-off-by: Jakub Kicinski

dccp/tcp: Reset saddr on failure after inet6?_hash_connect().

2022-11-23T04:15:36+00:00

When connect() is called on a socket bound to the wildcard address,
we change the socket's saddr to a local address.  If the socket
fails to connect() to the destination, we have to reset the saddr.

However, when an error occurs after inet_hash6?_connect() in
(dccp|tcp)_v[46]_conect(), we forget to reset saddr and leave
the socket bound to the address.

From the user's point of view, whether saddr is reset or not varies
with errno.  Let's fix this inconsistent behaviour.

Note that after this patch, the repro [0] will trigger the WARN_ON()
in inet_csk_get_port() again, but this patch is not buggy and rather
fixes a bug papering over the bhash2's bug for which we need another
fix.

For the record, the repro causes -EADDRNOTAVAIL in inet_hash6_connect()
by this sequence:

  s1 = socket()
  s1.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
  s1.bind(('127.0.0.1', 10000))
  s1.sendto(b'hello', MSG_FASTOPEN, (('127.0.0.1', 10000)))
  # or s1.connect(('127.0.0.1', 10000))

  s2 = socket()
  s2.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
  s2.bind(('0.0.0.0', 10000))
  s2.connect(('127.0.0.1', 10000))  # -EADDRNOTAVAIL

  s2.listen(32)  # WARN_ON(inet_csk(sk)->icsk_bind2_hash != tb2);

[0]: https://syzkaller.appspot.com/bug?extid=015d756bbd1f8b5c8f09

Fixes: 3df80d9320bc ("[DCCP]: Introduce DCCPv6")
Fixes: 7c657876b63c ("[DCCP]: Initial implementation")
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima 
Acked-by: Joanne Koong 
Reviewed-by: Eric Dumazet 
Signed-off-by: Jakub Kicinski

dccp: Call inet6_destroy_sock() via sk->sk_destruct().

2022-10-24T08:40:38+00:00

After commit d38afeec26ed ("tcp/udp: Call inet6_destroy_sock()
in IPv6 sk->sk_destruct()."), we call inet6_destroy_sock() in
sk->sk_destruct() by setting inet6_sock_destruct() to it to make
sure we do not leak inet6-specific resources.

DCCP sets its own sk->sk_destruct() in the dccp_init_sock(), and
DCCPv6 socket shares it by calling the same init function via
dccp_v6_init_sock().

To call inet6_sock_destruct() from DCCPv6 sk->sk_destruct(), we
export it and set dccp_v6_sk_destruct() in the init function.

Signed-off-by: Kuniyuki Iwashima 
Signed-off-by: David S. Miller

net: Add a bhash2 table hashed by port and address

2022-08-25T02:30:07+00:00

The current bind hashtable (bhash) is hashed by port only.
In the socket bind path, we have to check for bind conflicts by
traversing the specified port's inet_bind_bucket while holding the
hashbucket's spinlock (see inet_csk_get_port() and
inet_csk_bind_conflict()). In instances where there are tons of
sockets hashed to the same port at different addresses, the bind
conflict check is time-intensive and can cause softirq cpu lockups,
as well as stops new tcp connections since __inet_inherit_port()
also contests for the spinlock.

This patch adds a second bind table, bhash2, that hashes by
port and sk->sk_rcv_saddr (ipv4) and sk->sk_v6_rcv_saddr (ipv6).
Searching the bhash2 table leads to significantly faster conflict
resolution and less time holding the hashbucket spinlock.

Please note a few things:
* There can be the case where the a socket's address changes after it
has been bound. There are two cases where this happens:

  1) The case where there is a bind() call on INADDR_ANY (ipv4) or
  IPV6_ADDR_ANY (ipv6) and then a connect() call. The kernel will
  assign the socket an address when it handles the connect()

  2) In inet_sk_reselect_saddr(), which is called when rebuilding the
  sk header and a few pre-conditions are met (eg rerouting fails).

In these two cases, we need to update the bhash2 table by removing the
entry for the old address, and add a new entry reflecting the updated
address.

* The bhash2 table must have its own lock, even though concurrent
accesses on the same port are protected by the bhash lock. Bhash2 must
have its own lock to protect against cases where sockets on different
ports hash to different bhash hashbuckets but to the same bhash2
hashbucket.

This brings up a few stipulations:
  1) When acquiring both the bhash and the bhash2 lock, the bhash2 lock
  will always be acquired after the bhash lock and released before the
  bhash lock is released.

  2) There are no nested bhash2 hashbucket locks. A bhash2 lock is always
  acquired+released before another bhash2 lock is acquired+released.

* The bhash table cannot be superseded by the bhash2 table because for
bind requests on INADDR_ANY (ipv4) or IPV6_ADDR_ANY (ipv6), every socket
bound to that port must be checked for a potential conflict. The bhash
table is the only source of port->socket associations.

Signed-off-by: Joanne Koong 
Signed-off-by: Jakub Kicinski

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

2022-05-19T18:23:59+00:00

drivers/net/ethernet/mellanox/mlx5/core/main.c
  b33886971dbc ("net/mlx5: Initialize flow steering during driver probe")
  40379a0084c2 ("net/mlx5_fpga: Drop INNOVA TLS support")
  f2b41b32cde8 ("net/mlx5: Remove ipsec_ops function table")
https://lore.kernel.org/all/20220519040345.6yrjromcdistu7vh@sx1/
  16d42d313350 ("net/mlx5: Drain fw_reset when removing device")
  8324a02c342a ("net/mlx5: Add exit route when waiting for FW")
https://lore.kernel.org/all/20220519114119.060ce014@canb.auug.org.au/

tools/testing/selftests/net/mptcp/mptcp_join.sh
  e274f7154008 ("selftests: mptcp: add subflow limits test-cases")
  b6e074e171bc ("selftests: mptcp: add infinite map testcase")
  5ac1d2d63451 ("selftests: mptcp: Add tests for userspace PM type")
https://lore.kernel.org/all/20220516111918.366d747f@canb.auug.org.au/

net/mptcp/options.c
  ba2c89e0ea74 ("mptcp: fix checksum byte order")
  1e39e5a32ad7 ("mptcp: infinite mapping sending")
  ea66758c1795 ("tcp: allow MPTCP to update the announced window")
https://lore.kernel.org/all/20220519115146.751c3a37@canb.auug.org.au/

net/mptcp/pm.c
  95d686517884 ("mptcp: fix subflow accounting on close")
  4d25247d3ae4 ("mptcp: bypass in-kernel PM restrictions for non-kernel PMs")
https://lore.kernel.org/all/20220516111435.72f35dca@canb.auug.org.au/

net/mptcp/subflow.c
  ae66fb2ba6c3 ("mptcp: Do TCP fallback on early DSS checksum failure")
  0348c690ed37 ("mptcp: add the fallback check")
  f8d4bcacff3b ("mptcp: infinite mapping receiving")
https://lore.kernel.org/all/20220519115837.380bb8d4@canb.auug.org.au/

Signed-off-by: Jakub Kicinski

dccp: use READ_ONCE() to read sk->sk_bound_dev_if

2022-05-16T09:31:06+00:00

When reading listener sk->sk_bound_dev_if locklessly,
we must use READ_ONCE().

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

Revert "tcp/dccp: get rid of inet_twsk_purge()"

2022-05-13T11:24:12+00:00

This reverts commits:

0dad4087a86a2cbe177404dc73f18ada26a2c390 ("tcp/dccp: get rid of inet_twsk_purge()")
d507204d3c5cc57d9a8bdf0a477615bb59ea1611 ("tcp/dccp: add tw->tw_bslot")

As Leonard pointed out, a newly allocated netns can happen
to reuse a freed 'struct net'.

While TCP TW timers were covered by my patches, other things were not:

1) Lookups in rx path (INET_MATCH() and INET6_MATCH()), as they look
  at 4-tuple plus the 'struct net' pointer.

2) /proc/net/tcp[6] and inet_diag, same reason.

3) hashinfo->bhash[], same reason.

Fixing all this seems risky, lets instead revert.

In the future, we might have a per netns tcp hash table, or
a per netns list of timewait sockets...

Fixes: 0dad4087a86a ("tcp/dccp: get rid of inet_twsk_purge()")
Signed-off-by: Eric Dumazet 
Reported-by: Leonard Crestez 
Tested-by: Leonard Crestez 
Signed-off-by: David S. Miller