From: Gioh Kim <gi-oh.kim@cloud.ionos.com>

Date: Fri, 28 May 2021 13:30:15 +0200

Subject: RDMA/rtrs-srv: Fix memory leak of unfreed rtrs_srv_stats object

Patch-mainline: v5.14-rc1

Git-commit: 2371c40354509746e4a4dad09a752e027a30f148

References: jsc#SLE-15176

When closing a session, currently the rtrs_srv_stats object in the

closing session is freed by kobject release. But if it failed

to create a session by various reasons, it must free the rtrs_srv_stats

object directly because kobject is not created yet.

This problem is found by kmemleak as below:

1. One client machine maps /dev/nullb0 with session name 'bla':

root@test1:~# echo "sessname=bla path=ip:192.168.122.190 \

device_path=/dev/nullb0" > /sys/devices/virtual/rnbd-client/ctl/map_device

2. Another machine failed to create a session with the same name 'bla':

root@test2:~# echo "sessname=bla path=ip:192.168.122.190 \

device_path=/dev/nullb1" > /sys/devices/virtual/rnbd-client/ctl/map_device

-bash: echo: write error: Connection reset by peer

3. The kmemleak on server machine reported an error:

unreferenced object 0xffff888033cdc800 (size 128):

  comm "kworker/2:1", pid 83, jiffies 4295086585 (age 2508.680s)

  hex dump (first 32 bytes):

    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................

    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................

  backtrace:

    [<00000000a72903b2>] __alloc_sess+0x1d4/0x1250 [rtrs_server]

    [<00000000d1e5321e>] rtrs_srv_rdma_cm_handler+0xc31/0xde0 [rtrs_server]

    [<00000000bb2f6e7e>] cma_ib_req_handler+0xdc5/0x2b50 [rdma_cm]

    [<00000000e896235d>] cm_process_work+0x2d/0x100 [ib_cm]

    [<00000000b6866c5f>] cm_req_handler+0x11bc/0x1c40 [ib_cm]

    [<000000005f5dd9aa>] cm_work_handler+0xe65/0x3cf2 [ib_cm]

    [<00000000610151e7>] process_one_work+0x4bc/0x980

    [<00000000541e0f77>] worker_thread+0x78/0x5c0

    [<00000000423898ca>] kthread+0x191/0x1e0

    [<000000005a24b239>] ret_from_fork+0x3a/0x50

Fixes: 39c2d639ca183 ("RDMA/rtrs-srv: Set .release function for rtrs srv device during device init")

Link: https://lore.kernel.org/r/20210528113018.52290-18-jinpu.wang@ionos.com

Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>

Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>

Signed-off-by: Jack Wang <jinpu.wang@ionos.com>

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>

---

 drivers/infiniband/ulp/rtrs/rtrs-srv.c |    1 +

 1 file changed, 1 insertion(+)

--- a/drivers/infiniband/ulp/rtrs/rtrs-srv.c

+++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.c

@@ -1496,6 +1496,7 @@ static void free_sess(struct rtrs_srv_se

 		kobject_del(&sess->kobj);

 		kobject_put(&sess->kobj);

 	} else {

+		kfree(sess->stats);

 		kfree(sess);

 	}

 }