diff options
| author | D. Wythe <alibuda@linux.alibaba.com> | 2023-03-08 11:17:12 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-22 15:33:45 +0300 |
| commit | 3c270435db8aa34929263dddae8fd050f5216ecb (patch) | |
| tree | 474840d7c7a0f738ed71c104368edef11f729f2e /net/smc/smc_cdc.c | |
| parent | 1a1682abf7399318ac074b1f2ac6a8c992b5b3da (diff) | |
| download | linux-3c270435db8aa34929263dddae8fd050f5216ecb.tar.xz | |
net/smc: fix NULL sndbuf_desc in smc_cdc_tx_handler()
[ Upstream commit 22a825c541d775c1dbe7b2402786025acad6727b ]
When performing a stress test on SMC-R by rmmod mlx5_ib driver
during the wrk/nginx test, we found that there is a probability
of triggering a panic while terminating all link groups.
This issue dues to the race between smc_smcr_terminate_all()
and smc_buf_create().
smc_smcr_terminate_all
smc_buf_create
/* init */
conn->sndbuf_desc = NULL;
...
__smc_lgr_terminate
smc_conn_kill
smc_close_abort
smc_cdc_get_slot_and_msg_send
__softirqentry_text_start
smc_wr_tx_process_cqe
smc_cdc_tx_handler
READ(conn->sndbuf_desc->len);
/* panic dues to NULL sndbuf_desc */
conn->sndbuf_desc = xxx;
This patch tries to fix the issue by always to check the sndbuf_desc
before send any cdc msg, to make sure that no null pointer is
seen during cqe processing.
Fixes: 0b29ec643613 ("net/smc: immediate termination for SMCR link groups")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Link: https://lore.kernel.org/r/1678263432-17329-1-git-send-email-alibuda@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/smc/smc_cdc.c')
| -rw-r--r-- | net/smc/smc_cdc.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c index 53f63bfbaf5f..89105e95b452 100644 --- a/net/smc/smc_cdc.c +++ b/net/smc/smc_cdc.c @@ -114,6 +114,9 @@ int smc_cdc_msg_send(struct smc_connection *conn, union smc_host_cursor cfed; int rc; + if (unlikely(!READ_ONCE(conn->sndbuf_desc))) + return -ENOBUFS; + smc_cdc_add_pending_send(conn, pend); conn->tx_cdc_seq++; |