From: Jack Wang <jinpu.wang@cloud.ionos.com>
Date: Tue, 16 Feb 2021 15:38:07 +0100
Subject: RDMA/rtrs-srv: Do not pass a valid pointer to PTR_ERR()
Patch-mainline: v5.12-rc1
Git-commit: ed408529679737a9a7ad816c8de5d59ba104bb11
References: jsc#SLE-15176
smatch gives the warning:
drivers/infiniband/ulp/rtrs/rtrs-srv.c:1805 rtrs_rdma_connect() warn: passing zero to 'PTR_ERR'
Which is trying to say smatch has shown that srv is not an error pointer
and thus cannot be passed to PTR_ERR.
The solution is to move the list_add() down after full initilization of
rtrs_srv. To avoid holding the srv_mutex too long, only hold it during the
list operation as suggested by Leon.
Fixes: 03e9b33a0fd6 ("RDMA/rtrs: Only allow addition of path to an already established session")
Link: https://lore.kernel.org/r/20210216143807.65923-1-jinpu.wang@cloud.ionos.com
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/infiniband/ulp/rtrs/rtrs-srv.c | 20 +++++++-------------
1 file changed, 7 insertions(+), 13 deletions(-)
--- a/drivers/infiniband/ulp/rtrs/rtrs-srv.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
@@ -1360,21 +1360,18 @@ static struct rtrs_srv *get_or_create_sr
return srv;
}
}
+ mutex_unlock(&ctx->srv_mutex);
/*
* If this request is not the first connection request from the
* client for this session then fail and return error.
*/
- if (!first_conn) {
- mutex_unlock(&ctx->srv_mutex);
+ if (!first_conn)
return ERR_PTR(-ENXIO);
- }
/* need to allocate a new srv */
srv = kzalloc(sizeof(*srv), GFP_KERNEL);
- if (!srv) {
- mutex_unlock(&ctx->srv_mutex);
+ if (!srv)
return ERR_PTR(-ENOMEM);
- }
INIT_LIST_HEAD(&srv->paths_list);
mutex_init(&srv->paths_mutex);
@@ -1384,8 +1381,6 @@ static struct rtrs_srv *get_or_create_sr
srv->ctx = ctx;
device_initialize(&srv->dev);
srv->dev.release = rtrs_srv_dev_release;
- list_add(&srv->ctx_list, &ctx->srv_list);
- mutex_unlock(&ctx->srv_mutex);
srv->chunks = kcalloc(srv->queue_depth, sizeof(*srv->chunks),
GFP_KERNEL);
@@ -1398,6 +1393,9 @@ static struct rtrs_srv *get_or_create_sr
goto err_free_chunks;
}
refcount_set(&srv->refcount, 1);
+ mutex_lock(&ctx->srv_mutex);
+ list_add(&srv->ctx_list, &ctx->srv_list);
+ mutex_unlock(&ctx->srv_mutex);
return srv;
@@ -1812,11 +1810,7 @@ static int rtrs_rdma_connect(struct rdma
}
recon_cnt = le16_to_cpu(msg->recon_cnt);
srv = get_or_create_srv(ctx, &msg->paths_uuid, msg->first_conn);
- /*
- * "refcount == 0" happens if a previous thread calls get_or_create_srv
- * allocate srv, but chunks of srv are not allocated yet.
- */
- if (IS_ERR(srv) || refcount_read(&srv->refcount) == 0) {
+ if (IS_ERR(srv)) {
err = PTR_ERR(srv);
goto reject_w_err;
}