[PATCH net] net/smc: delete buf_desc from buffer list under lock protection

[Wen Gu <guwen@linux.alibaba.com>]

The operations to link group buffer list should be protected by
sndbufs_lock or rmbs_lock. So fix it.

Fixes: 3e034725c0d8 ("net/smc: common functions for RMBs and send buffers")
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
---
 net/smc/smc_core.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 3b95828d9976..ecfea8c38da9 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -1368,18 +1368,24 @@ static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
 {
 	struct smc_buf_desc *buf_desc, *bf_desc;
 	struct list_head *buf_list;
+	struct rw_semaphore *lock;
 	int i;
 
 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
-		if (is_rmb)
+		if (is_rmb) {
 			buf_list = &lgr->rmbs[i];
-		else
+			lock = &lgr->rmbs_lock;
+		} else {
 			buf_list = &lgr->sndbufs[i];
+			lock = &lgr->sndbufs_lock;
+		}
+		down_write(lock);
 		list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
 					 list) {
 			list_del(&buf_desc->list);
 			smc_buf_free(lgr, is_rmb, buf_desc);
 		}
+		up_write(lock);
 	}
 }
 
-- 
2.32.0.3.g01195cf9f