The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 20c7840a77ddcb2ed2fbd66e8197db2868495751 Mon Sep 17 00:00:00 2001
From: "Michael J. Ruhl" <michael.j.ruhl@xxxxxxxxx>
Date: Sun, 9 Apr 2017 10:15:32 -0700
Subject: [PATCH] IB/core: If the MGID/MLID pair is not on the list return an
error
A list of MGID/MLID pairs is built when doing a multicast attach. When
the multicast detach is called, the list is searched, and regardless of
the search outcome, the driver detach is called.
If an MGID/MLID pair is not on the list, driver detach should not be
called, and an error should be returned. Calling the driver without
removing an MGID/MLID pair from the list can leave the core and driver
out of sync.
Fixes: f4e401562c11 ("IB/uverbs: track multicast group membership for userspace QPs")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 7a4a10ef8b49..cb3c426c0dad 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -2658,6 +2658,7 @@ ssize_t ib_uverbs_detach_mcast(struct ib_uverbs_file *file,
struct ib_qp *qp;
struct ib_uverbs_mcast_entry *mcast;
int ret = -EINVAL;
+ bool found = false;
if (copy_from_user(&cmd, buf, sizeof cmd))
return -EFAULT;
@@ -2669,18 +2670,22 @@ ssize_t ib_uverbs_detach_mcast(struct ib_uverbs_file *file,
obj = container_of(qp->uobject, struct ib_uqp_object, uevent.uobject);
mutex_lock(&obj->mcast_lock);
- ret = ib_detach_mcast(qp, (union ib_gid *) cmd.gid, cmd.mlid);
- if (ret)
- goto out_put;
-
list_for_each_entry(mcast, &obj->mcast_list, list)
if (cmd.mlid == mcast->lid &&
!memcmp(cmd.gid, mcast->gid.raw, sizeof mcast->gid.raw)) {
list_del(&mcast->list);
kfree(mcast);
+ found = true;
break;
}
+ if (!found) {
+ ret = -EINVAL;
+ goto out_put;
+ }
+
+ ret = ib_detach_mcast(qp, (union ib_gid *)cmd.gid, cmd.mlid);
+
out_put:
mutex_unlock(&obj->mcast_lock);
uobj_put_obj_read(qp);