[PATCH net 0/2] net/smc: fix kernel panic caused by race of smc_sock

Dust Li
2021-12-28T09:03:28Z

This patchset fixes the race between smc_release triggered by
close(2) and cdc_handle triggered by underlaying RDMA device.

The race is caused because the smc_connection may been released
before the pending tx CDC messages got its CQEs. In order to fix
this, I add a counter to track how many pending WRs we have posted
through the smc_connection, and only release the smc_connection
after there is no pending WRs on the connection.

The first patch prevents posting WR on a QP that is not in RTS
state. This patch is needed because if we post WR on a QP that
is not in RTS state, ib_post_send() may success but no CQE will
return, and that will confuse the counter tracking the pending
WRs.

The second patch add a counter to track how many WRs were posted
through the smc_connection, and don't reset the QP on link destroying
to prevent leak of the counter.

Dust Li (2):
net/smc: don't send CDC/LLC message if link not ready
net/smc: fix kernel panic caused by race of smc_sock

net/smc/smc.h | 5 +++++
net/smc/smc_cdc.c | 52 +++++++++++++++++++++-------------------------
net/smc/smc_cdc.h | 2 +-
net/smc/smc_core.c | 27 ++++++++++++++++++------
net/smc/smc_core.h | 6 ++++++
net/smc/smc_ib.c | 4 ++--
net/smc/smc_ib.h | 1 +
net/smc/smc_llc.c | 2 +-
net/smc/smc_wr.c | 45 +++++----------------------------------
net/smc/smc_wr.h | 5 ++---
10 files changed, 68 insertions(+), 81 deletions(-)

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2.19.1.3.ge56e4f7