Commit graph

15 commits

Author SHA1 Message Date
Guangguan Wang
ce3b97bfca net/smc: check return value of sock_recvmsg when draining clc data
[ Upstream commit c5b8ee5022a19464783058dc6042e8eefa34e8cd ]

When receiving clc msg, the field length in smc_clc_msg_hdr indicates the
length of msg should be received from network and the value should not be
fully trusted as it is from the network. Once the value of length exceeds
the value of buflen in function smc_clc_wait_msg it may run into deadloop
when trying to drain the remaining data exceeding buflen.

This patch checks the return value of sock_recvmsg when draining data in
case of deadloop in draining.

Fixes: fb4f79264c0f ("net/smc: tolerate future SMCD versions")
Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: D. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-15 16:29:41 +01:00
Guangguan Wang
f93714002b net/smc: check iparea_offset and ipv6_prefixes_cnt when receiving proposal msg
[ Upstream commit a29e220d3c8edbf0e1beb0f028878a4a85966556 ]

When receiving proposal msg in server, the field iparea_offset
and the field ipv6_prefixes_cnt in proposal msg are from the
remote client and can not be fully trusted. Especially the
field iparea_offset, once exceed the max value, there has the
chance to access wrong address, and crash may happen.

This patch checks iparea_offset and ipv6_prefixes_cnt before using them.

Fixes: e7b7a64a8493 ("smc: support variable CLC proposal messages")
Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: D. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-15 16:29:41 +01:00
Guangguan Wang
61ad4ce8cb net/smc: check sndbuf_space again after NOSPACE flag is set in smc_poll
[ Upstream commit 679e9ddcf90dbdf98aaaa71a492454654b627bcb ]

When application sending data more than sndbuf_space, there have chances
application will sleep in epoll_wait, and will never be wakeup again. This
is caused by a race between smc_poll and smc_cdc_tx_handler.

application                                      tasklet
smc_tx_sendmsg(len > sndbuf_space)   |
epoll_wait for EPOLL_OUT,timeout=0   |
  smc_poll                           |
    if (!smc->conn.sndbuf_space)     |
                                     |  smc_cdc_tx_handler
                                     |    atomic_add sndbuf_space
                                     |    smc_tx_sndbuf_nonfull
                                     |      if (!test_bit SOCK_NOSPACE)
                                     |        do not sk_write_space;
      set_bit SOCK_NOSPACE;          |
    return mask=0;                   |

Application will sleep in epoll_wait as smc_poll returns 0. And
smc_cdc_tx_handler will not call sk_write_space because the SOCK_NOSPACE
has not be set. If there is no inflight cdc msg, sk_write_space will not be
called any more, and application will sleep in epoll_wait forever.
So check sndbuf_space again after NOSPACE flag is set to break the race.

Fixes: 8dce2786a290 ("net/smc: smc_poll improvements")
Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-15 16:29:41 +01:00
Ksawlii
e913a37a4d Revert "net/smc: Allow SMC-D 1MB DMB allocations"
This reverts commit 3ab7fb1f47.
2024-11-24 00:23:56 +01:00
Ksawlii
43674763e3 Revert "net/smc: set rmb's SG_MAX_SINGLE_ALLOC limitation only when CONFIG_ARCH_NO_SG_CHAIN is defined"
This reverts commit 3bf0715dbb.
2024-11-24 00:23:56 +01:00
Li RongQing
cc66ebbb5f net/smc: Fix searching in list of known pnetids in smc_pnet_add_pnetid
[ Upstream commit 82ac39ebd6db0c9f7a97a934bda1e3e101a9d201 ]

pnetid of pi (not newly allocated pe) should be compared

Fixes: e888a2e8337c ("net/smc: introduce list of pnetids for Ethernet devices")
Reviewed-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>
Link: https://patch.msgid.link/20241014115321.33234-1-lirongqing@baidu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:21:59 +01:00
Guangguan Wang
3bf0715dbb net/smc: set rmb's SG_MAX_SINGLE_ALLOC limitation only when CONFIG_ARCH_NO_SG_CHAIN is defined
[ Upstream commit 3ac14b9dfbd345e891d48d89f6c2fa519848f0f4 ]

SG_MAX_SINGLE_ALLOC is used to limit maximum number of entries that
will be allocated in one piece of scatterlist. When the entries of
scatterlist exceeds SG_MAX_SINGLE_ALLOC, sg chain will be used. From
commit 7c703e54cc71 ("arch: switch the default on ARCH_HAS_SG_CHAIN"),
we can know that the macro CONFIG_ARCH_NO_SG_CHAIN is used to identify
whether sg chain is supported. So, SMC-R's rmb buffer should be limited
by SG_MAX_SINGLE_ALLOC only when the macro CONFIG_ARCH_NO_SG_CHAIN is
defined.

Fixes: a3fe3d01bd0d ("net/smc: introduce sg-logic for RMBs")
Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Co-developed-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:20:06 +01:00
Stefan Raspl
3ab7fb1f47 net/smc: Allow SMC-D 1MB DMB allocations
[ Upstream commit 67161779a9ea926fccee8de047ae66cbd3482b91 ]

Commit a3fe3d01bd0d7 ("net/smc: introduce sg-logic for RMBs") introduced
a restriction for RMB allocations as used by SMC-R. However, SMC-D does
not use scatter-gather lists to back its DMBs, yet it was limited by
this restriction, still.
This patch exempts SMC, but limits allocations to the maximum RMB/DMB
size respectively.

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 3ac14b9dfbd3 ("net/smc: set rmb's SG_MAX_SINGLE_ALLOC limitation only when CONFIG_ARCH_NO_SG_CHAIN is defined")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:20:06 +01:00
Eric Dumazet
15397674ac net/smc: reduce rtnl pressure in smc_pnet_create_pnetids_list()
[ Upstream commit 00af2aa93b76b1bade471ad0d0525d4d29ca5cc0 ]

Many syzbot reports show extreme rtnl pressure, and many of them hint
that smc acquires rtnl in netns creation for no good reason [1]

This patch returns early from smc_pnet_net_init()
if there is no netdevice yet.

I am not even sure why smc_pnet_create_pnetids_list() even exists,
because smc_pnet_netdev_event() is also calling
smc_pnet_add_base_pnetid() when handling NETDEV_UP event.

[1] extract of typical syzbot reports

2 locks held by syz-executor.3/12252:
  #0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.4/12253:
  #0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.1/12257:
  #0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.2/12261:
  #0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.0/12265:
  #0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.3/12268:
  #0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.4/12271:
  #0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.1/12274:
  #0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.2/12280:
  #0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
  #1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wenjia Zhang <wenjia@linux.ibm.com>
Cc: Jan Karcher <jaka@linux.ibm.com>
Cc: "D. Wythe" <alibuda@linux.alibaba.com>
Cc: Tony Lu <tonylu@linux.alibaba.com>
Cc: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Link: https://lore.kernel.org/r/20240302100744.3868021-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 09:23:13 +01:00
Wen Gu
1c3ec92005 net/smc: fix illegal rmb_desc access in SMC-D connection dump
[ Upstream commit dbc153fd3c142909e564bb256da087e13fbf239c ]

A crash was found when dumping SMC-D connections. It can be reproduced
by following steps:

- run nginx/wrk test:
  smc_run nginx
  smc_run wrk -t 16 -c 1000 -d <duration> -H 'Connection: Close' <URL>

- continuously dump SMC-D connections in parallel:
  watch -n 1 'smcss -D'

 BUG: kernel NULL pointer dereference, address: 0000000000000030
 CPU: 2 PID: 7204 Comm: smcss Kdump: loaded Tainted: G	E      6.7.0+ #55
 RIP: 0010:__smc_diag_dump.constprop.0+0x5e5/0x620 [smc_diag]
 Call Trace:
  <TASK>
  ? __die+0x24/0x70
  ? page_fault_oops+0x66/0x150
  ? exc_page_fault+0x69/0x140
  ? asm_exc_page_fault+0x26/0x30
  ? __smc_diag_dump.constprop.0+0x5e5/0x620 [smc_diag]
  ? __kmalloc_node_track_caller+0x35d/0x430
  ? __alloc_skb+0x77/0x170
  smc_diag_dump_proto+0xd0/0xf0 [smc_diag]
  smc_diag_dump+0x26/0x60 [smc_diag]
  netlink_dump+0x19f/0x320
  __netlink_dump_start+0x1dc/0x300
  smc_diag_handler_dump+0x6a/0x80 [smc_diag]
  ? __pfx_smc_diag_dump+0x10/0x10 [smc_diag]
  sock_diag_rcv_msg+0x121/0x140
  ? __pfx_sock_diag_rcv_msg+0x10/0x10
  netlink_rcv_skb+0x5a/0x110
  sock_diag_rcv+0x28/0x40
  netlink_unicast+0x22a/0x330
  netlink_sendmsg+0x1f8/0x420
  __sock_sendmsg+0xb0/0xc0
  ____sys_sendmsg+0x24e/0x300
  ? copy_msghdr_from_user+0x62/0x80
  ___sys_sendmsg+0x7c/0xd0
  ? __do_fault+0x34/0x160
  ? do_read_fault+0x5f/0x100
  ? do_fault+0xb0/0x110
  ? __handle_mm_fault+0x2b0/0x6c0
  __sys_sendmsg+0x4d/0x80
  do_syscall_64+0x69/0x180
  entry_SYSCALL_64_after_hwframe+0x6e/0x76

It is possible that the connection is in process of being established
when we dump it. Assumed that the connection has been registered in a
link group by smc_conn_create() but the rmb_desc has not yet been
initialized by smc_buf_create(), thus causing the illegal access to
conn->rmb_desc. So fix it by checking before dump.

Fixes: 4b1b7d3b30a6 ("net/smc: add SMC-D diag support")
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 12:12:59 +01:00
D. Wythe
3ed7d1e502 net/smc: avoid data corruption caused by decline
[ Upstream commit e6d71b437abc2f249e3b6a1ae1a7228e09c6e563 ]

We found a data corruption issue during testing of SMC-R on Redis
applications.

The benchmark has a low probability of reporting a strange error as
shown below.

"Error: Protocol error, got "\xe2" as reply type byte"

Finally, we found that the retrieved error data was as follows:

0xE2 0xD4 0xC3 0xD9 0x04 0x00 0x2C 0x20 0xA6 0x56 0x00 0x16 0x3E 0x0C
0xCB 0x04 0x02 0x01 0x00 0x00 0x20 0x00 0x00 0x00 0x00 0x00 0x00 0x00
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0xE2

It is quite obvious that this is a SMC DECLINE message, which means that
the applications received SMC protocol message.
We found that this was caused by the following situations:

client                  server
        ¦  clc proposal
        ------------->
        ¦  clc accept
        <-------------
        ¦  clc confirm
        ------------->
wait llc confirm
			send llc confirm
        ¦failed llc confirm
        ¦   x------
(after 2s)timeout
                        wait llc confirm rsp

wait decline

(after 1s) timeout
                        (after 2s) timeout
        ¦   decline
        -------------->
        ¦   decline
        <--------------

As a result, a decline message was sent in the implementation, and this
message was read from TCP by the already-fallback connection.

This patch double the client timeout as 2x of the server value,
With this simple change, the Decline messages should never cross or
collide (during Confirm link timeout).

This issue requires an immediate solution, since the protocol updates
involve a more long-term solution.

Fixes: 0fb0b02bd6fd ("net/smc: adapt SMC client code to use the LLC flow")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 12:10:55 +01:00
D. Wythe
1c089c509f net/smc: put sk reference if close work was canceled
[ Upstream commit aa96fbd6d78d9770323b21e2c92bd38821be8852 ]

Note that we always hold a reference to sock when attempting
to submit close_work. Therefore, if we have successfully
canceled close_work from pending, we MUST release that reference
to avoid potential leaks.

Fixes: 42bfba9eaa33 ("net/smc: immediate termination for SMCD link groups")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 11:43:08 +01:00
D. Wythe
a9cbe7fa6f net/smc: allow cdc msg send rather than drop it with NULL sndbuf_desc
[ Upstream commit c5bf605ba4f9d6fbbb120595ab95002f4716edcb ]

This patch re-fix the issues mentioned by commit 22a825c541d7
("net/smc: fix NULL sndbuf_desc in smc_cdc_tx_handler()").

Blocking sending message do solve the issues though, but it also
prevents the peer to receive the final message. Besides, in logic,
whether the sndbuf_desc is NULL or not have no impact on the processing
of cdc message sending.

Hence that, this patch allows the cdc message sending but to check the
sndbuf_desc with care in smc_cdc_tx_handler().

Fixes: 22a825c541d7 ("net/smc: fix NULL sndbuf_desc in smc_cdc_tx_handler()")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 11:43:08 +01:00
D. Wythe
b1d3be5b52 net/smc: fix dangling sock under state SMC_APPFINCLOSEWAIT
[ Upstream commit 5211c9729484c923f8d2e06bd29f9322cc42bb8f ]

Considering scenario:

				smc_cdc_rx_handler
__smc_release
				sock_set_flag
smc_close_active()
sock_set_flag

__set_bit(DEAD)			__set_bit(DONE)

Dues to __set_bit is not atomic, the DEAD or DONE might be lost.
if the DEAD flag lost, the state SMC_CLOSED  will be never be reached
in smc_close_passive_work:

if (sock_flag(sk, SOCK_DEAD) &&
	smc_close_sent_any_close(conn)) {
	sk->sk_state = SMC_CLOSED;
} else {
	/* just shutdown, but not yet closed locally */
	sk->sk_state = SMC_APPFINCLOSEWAIT;
}

Replace sock_set_flags or __set_bit to set_bit will fix this problem.
Since set_bit is atomic.

Fixes: b38d732477e4 ("smc: socket closing and linkgroup cleanup")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 11:43:08 +01:00
Gabriel2392
7ed7ee9edf Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00