linux-stable.git/net/smc, branch linux-5.14.y

net/smc: fix sk_refcnt underflow on linkdown and fallback

2021-11-17T10:04:44+00:00

[ Upstream commit e5d5aadcf3cd59949316df49c27cb21788d7efe4 ]

We got the following WARNING when running ab/nginx
test with RDMA link flapping (up-down-up).
The reason is when smc_sock fallback and at linkdown
happens simultaneously, we may got the following situation:

__smc_lgr_terminate()
 --> smc_conn_kill()
    --> smc_close_active_abort()
           smc_sock->sk_state = SMC_CLOSED
           sock_put(smc_sock)

smc_sock was set to SMC_CLOSED and sock_put() been called
when terminate the link group. But later application call
close() on the socket, then we got:

__smc_release():
    if (smc_sock->fallback)
        smc_sock->sk_state = SMC_CLOSED
        sock_put(smc_sock)

Again we set the smc_sock to CLOSED through it's already
in CLOSED state, and double put the refcnt, so the following
warning happens:

refcount_t: underflow; use-after-free.
WARNING: CPU: 5 PID: 860 at lib/refcount.c:28 refcount_warn_saturate+0x8d/0xf0
Modules linked in:
CPU: 5 PID: 860 Comm: nginx Not tainted 5.10.46+ #403
Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 8c24b4c 04/01/2014
RIP: 0010:refcount_warn_saturate+0x8d/0xf0
Code: 05 5c 1e b5 01 01 e8 52 25 bc ff 0f 0b c3 80 3d 4f 1e b5 01 00 75 ad 48

RSP: 0018:ffffc90000527e50 EFLAGS: 00010286
RAX: 0000000000000026 RBX: ffff8881300df2c0 RCX: 0000000000000027
RDX: 0000000000000000 RSI: ffff88813bd58040 RDI: ffff88813bd58048
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000001
R10: ffff8881300df2c0 R11: ffffc90000527c78 R12: ffff8881300df340
R13: ffff8881300df930 R14: ffff88810b3dad80 R15: ffff8881300df4f8
FS:  00007f739de8fb80(0000) GS:ffff88813bd40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000a01b008 CR3: 0000000111b64003 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 smc_release+0x353/0x3f0
 __sock_release+0x3d/0xb0
 sock_close+0x11/0x20
 __fput+0x93/0x230
 task_work_run+0x65/0xa0
 exit_to_user_mode_prepare+0xf9/0x100
 syscall_exit_to_user_mode+0x27/0x190
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

This patch adds check in __smc_release() to make
sure we won't do an extra sock_put() and set the
socket to CLOSED when its already in CLOSED state.

Fixes: 51f1de79ad8e (net/smc: replace sock_put worker by socket refcounting)
Signed-off-by: Dust Li 
Reviewed-by: Tony Lu 
Signed-off-by: Dust Li 
Acked-by: Karsten Graul 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net/smc: Correct spelling mistake to TCPF_SYN_RECV

2021-11-17T10:03:32+00:00

[ Upstream commit f3a3a0fe0b644582fa5d83dd94b398f99fc57914 ]

There should use TCPF_SYN_RECV instead of TCP_SYN_RECV.

Signed-off-by: Wen Gu 
Reviewed-by: Tony Lu 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net/smc: Fix smc_link->llc_testlink_time overflow

2021-11-17T10:03:31+00:00

[ Upstream commit c4a146c7cf5e8ad76231523b174d161bf152c6e7 ]

The value of llc_testlink_time is set to the value stored in
net->ipv4.sysctl_tcp_keepalive_time when linkgroup init. The value of
sysctl_tcp_keepalive_time is already jiffies, so we don't need to
multiply by HZ, which would cause smc_link->llc_testlink_time overflow,
and test_link send flood.

Signed-off-by: Tony Lu 
Reviewed-by: Xuan Zhuo 
Reviewed-by: Wen Gu 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net/smc: improved fix wait on already cleared link

2021-10-20T09:57:54+00:00

commit 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a upstream.

Commit 8f3d65c16679 ("net/smc: fix wait on already cleared link")
introduced link refcounting to avoid waits on already cleared links.
This patch extents and improves the refcounting to cover all
remaining possible cases for this kind of error situation.

Fixes: 15e1b99aadfb ("net/smc: no WR buffer wait for terminating link group")
Signed-off-by: Karsten Graul 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net/smc: fix 'workqueue leaked lock' in smc_conn_abort_work

2021-09-30T08:12:59+00:00

[ Upstream commit a18cee4791b1123d0a6579a7c89f4b87e48abe03 ]

The abort_work is scheduled when a connection was detected to be
out-of-sync after a link failure. The work calls smc_conn_kill(),
which calls smc_close_active_abort() and that might end up calling
smc_close_cancel_work().
smc_close_cancel_work() cancels any pending close_work and tx_work but
needs to release the sock_lock before and acquires the sock_lock again
afterwards. So when the sock_lock was NOT acquired before then it may
be held after the abort_work completes. Thats why the sock_lock is
acquired before the call to smc_conn_kill() in __smc_lgr_terminate(),
but this is missing in smc_conn_abort_work().

Fix that by acquiring the sock_lock first and release it after the
call to smc_conn_kill().

Fixes: b286a0651e44 ("net/smc: handle incoming CDC validation message")
Signed-off-by: Karsten Graul 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net/smc: add missing error check in smc_clc_prfx_set()

2021-09-30T08:12:59+00:00

[ Upstream commit 6c90731980655280ea07ce4b21eb97457bf86286 ]

Coverity stumbled over a missing error check in smc_clc_prfx_set():

*** CID 1475954:  Error handling issues  (CHECKED_RETURN)
/net/smc/smc_clc.c: 233 in smc_clc_prfx_set()
>>>     CID 1475954:  Error handling issues  (CHECKED_RETURN)
>>>     Calling "kernel_getsockname" without checking return value (as is done elsewhere 8 out of 10 times).
233     	kernel_getsockname(clcsock, (struct sockaddr *)&addrs);

Add the return code check in smc_clc_prfx_set().

Fixes: c246d942eabc ("net/smc: restructure netinfo for CLC proposal msgs")
Reported-by: Julian Wiedmann 
Signed-off-by: Karsten Graul 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net/smc: Correct smc link connection counter in case of smc client

2021-08-09T09:46:59+00:00

SMC clients may be assigned to a different link after the initial
connection between two peers was established. In such a case,
the connection counter was not correctly set.

Update the connection counter correctly when a smc client connection
is assigned to a different smc link.

Fixes: 07d51580ff65 ("net/smc: Add connection counters for links")
Signed-off-by: Guvenc Gulce 
Tested-by: Karsten Graul 
Signed-off-by: David S. Miller

net/smc: fix wait on already cleared link

2021-08-09T09:46:59+00:00

There can be a race between the waiters for a tx work request buffer
and the link down processing that finally clears the link. Although
all waiters are woken up before the link is cleared there might be
waiters which did not yet get back control and are still waiting.
This results in an access to a cleared wait queue head.

Fix this by introducing atomic reference counting around the wait calls,
and wait with the link clear processing until all waiters have finished.
Move the work request layer related calls into smc_wr.c and set the
link state to INACTIVE before calling smcr_link_clear() in
smc_llc_srv_add_link().

Fixes: 15e1b99aadfb ("net/smc: no WR buffer wait for terminating link group")
Signed-off-by: Karsten Graul 
Signed-off-by: Guvenc Gulce 
Signed-off-by: David S. Miller

net: sock: introduce sk_error_report

2021-06-29T18:28:21+00:00

This patch introduces a function wrapper to call the sk_error_report
callback. That will prepare to add additional handling whenever
sk_error_report is called, for example to trace socket errors.

Signed-off-by: Alexander Aring 
Signed-off-by: David S. Miller

net/smc: Ensure correct state of the socket in send path

2021-06-25T18:53:51+00:00

When smc_sendmsg() is called before the SMC socket initialization has
completed, smc_tx_sendmsg() will access un-initialized fields of the
SMC socket which results in a null-pointer dereference.
Fix this by checking the socket state first in smc_tx_sendmsg().

Fixes: e0e4b8fa5338 ("net/smc: Add SMC statistics support")
Reported-by: syzbot+5dda108b672b54141857@syzkaller.appspotmail.com
Reviewed-by: Karsten Graul 
Signed-off-by: Guvenc Gulce 
Signed-off-by: Karsten Graul 
Signed-off-by: David S. Miller