net/smc: check for valid ib_client_data

BugLink: https://bugs.launchpad.net/bugs/1869732
commit a2f2ef4a54c0d97aa6a8386f4ff23f36ebb488cf upstream.

In smc_ib_remove_dev() check if the provided ib device was actually
initialized for SMC before.

Reported-by: syzbot+84484ccebdd4e5451d91@syzkaller.appspotmail.com
Fixes: a4cf0443c414 ("smc: introduce SMC as an IB-client")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c
index 85304805754a7cc9d3d26ea5fd9f2290db8dbb2d..6fa17f2d703d91f33659434ff3dce86ddcb12ed6 100644 (file)
--- a/net/smc/smc_ib.c
+++ b/net/smc/smc_ib.c
@@ -505,6 +505,8 @@ static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
        struct smc_ib_device *smcibdev;
 
        smcibdev = ib_get_client_data(ibdev, &smc_ib_client);
+       if (!smcibdev || smcibdev->ibdev != ibdev)
+               return;
        ib_set_client_data(ibdev, &smc_ib_client, NULL);
        spin_lock(&smc_ib_devices.lock);
        list_del_init(&smcibdev->list); /* remove from smc_ib_devices */