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authorEli Cohen <eli@dev.mellanox.co.il>2012-01-03 20:36:48 -0800
committerGreg Kroah-Hartman <gregkh@suse.de>2012-01-12 11:29:24 -0800
commit585ea9bc6752c41d669ea0f4cee8f3954df326e0 (patch)
tree9089e0928ac101795d5d3dab93fc9dbac32d89ce
parent0d878668d0a4663a4807d413532f3a99496eebf4 (diff)
downloadvexpress-lsk-585ea9bc6752c41d669ea0f4cee8f3954df326e0.tar.gz
IB/uverbs: Protect QP multicast list
commit e214a0fe2b382fa302c036ecd6e6ffe99e3b9875 upstream. Userspace verbs multicast attach/detach operations on a QP are done while holding the rwsem of the QP for reading. That's not sufficient since a reader lock allows more than one reader to acquire the lock. However, multicast attach/detach does list manipulation that can corrupt the list if multiple threads run in parallel. Fix this by acquiring the rwsem as a writer to serialize attach/detach operations. Add idr_write_qp() and put_qp_write() to encapsulate this. This fixes oops seen when running applications that perform multicast joins/leaves. Reported by: Mike Dubman <miked@mellanox.com> Signed-off-by: Eli Cohen <eli@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/infiniband/core/uverbs_cmd.c21
1 files changed, 17 insertions, 4 deletions
diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 254f1649c73..e3db8ef4fe4 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -241,11 +241,24 @@ static struct ib_qp *idr_read_qp(int qp_handle, struct ib_ucontext *context)
return idr_read_obj(&ib_uverbs_qp_idr, qp_handle, context, 0);
}
+static struct ib_qp *idr_write_qp(int qp_handle, struct ib_ucontext *context)
+{
+ struct ib_uobject *uobj;
+
+ uobj = idr_write_uobj(&ib_uverbs_qp_idr, qp_handle, context);
+ return uobj ? uobj->object : NULL;
+}
+
static void put_qp_read(struct ib_qp *qp)
{
put_uobj_read(qp->uobject);
}
+static void put_qp_write(struct ib_qp *qp)
+{
+ put_uobj_write(qp->uobject);
+}
+
static struct ib_srq *idr_read_srq(int srq_handle, struct ib_ucontext *context)
{
return idr_read_obj(&ib_uverbs_srq_idr, srq_handle, context, 0);
@@ -2375,7 +2388,7 @@ ssize_t ib_uverbs_attach_mcast(struct ib_uverbs_file *file,
if (copy_from_user(&cmd, buf, sizeof cmd))
return -EFAULT;
- qp = idr_read_qp(cmd.qp_handle, file->ucontext);
+ qp = idr_write_qp(cmd.qp_handle, file->ucontext);
if (!qp)
return -EINVAL;
@@ -2404,7 +2417,7 @@ ssize_t ib_uverbs_attach_mcast(struct ib_uverbs_file *file,
kfree(mcast);
out_put:
- put_qp_read(qp);
+ put_qp_write(qp);
return ret ? ret : in_len;
}
@@ -2422,7 +2435,7 @@ ssize_t ib_uverbs_detach_mcast(struct ib_uverbs_file *file,
if (copy_from_user(&cmd, buf, sizeof cmd))
return -EFAULT;
- qp = idr_read_qp(cmd.qp_handle, file->ucontext);
+ qp = idr_write_qp(cmd.qp_handle, file->ucontext);
if (!qp)
return -EINVAL;
@@ -2441,7 +2454,7 @@ ssize_t ib_uverbs_detach_mcast(struct ib_uverbs_file *file,
}
out_put:
- put_qp_read(qp);
+ put_qp_write(qp);
return ret ? ret : in_len;
}