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RDMA/netlink: Fix locking around __ib_get_device_by_index

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Holding locks is mandatory when calling __ib_device_get_by_index,
otherwise there are races during the list iteration with device removal.

Since the locks are static to device.c, __ib_device_get_by_index can
never be called correctly by any user out side the file.

Make the function static and provide a safe function that gets the
correct locks and returns a kref'd pointer. Fix all callers.

Fixes: e5c9469efc ("RDMA/netlink: Add nldev device doit implementation")
Fixes: c3f66f7b00 ("RDMA/netlink: Implement nldev port doit callback")
Fixes: 7d02f605f0 ("RDMA/netlink: Add nldev port dumpit implementation")
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Leon Romanovsky 2018-01-01 13:07:15 +02:00 committed by Jason Gunthorpe
parent 16ba3defb8
commit f8978bd95c
3 changed files with 54 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/infiniband/core/core_priv.h
View File

@ -314,7 +314,7 @@ static inline int ib_mad_enforce_security(struct ib_mad_agent_private *map,
}
#endif
struct ib_device *__ib_device_get_by_index(u32 ifindex);
struct ib_device *ib_device_get_by_index(u32 ifindex);
/* RDMA device netlink */
void nldev_init(void);
void nldev_exit(void);

18
drivers/infiniband/core/device.c
View File

@ -134,7 +134,7 @@ static int ib_device_check_mandatory(struct ib_device *device)
return 0;
}
struct ib_device *__ib_device_get_by_index(u32 index)
static struct ib_device *__ib_device_get_by_index(u32 index)
{
struct ib_device *device;
@ -145,6 +145,22 @@ struct ib_device *__ib_device_get_by_index(u32 index)
return NULL;
}
/*
* Caller is responsible to return refrerence count by calling put_device()
*/
struct ib_device *ib_device_get_by_index(u32 index)
{
struct ib_device *device;
down_read(&lists_rwsem);
device = __ib_device_get_by_index(index);
if (device)
get_device(&device->dev);
up_read(&lists_rwsem);
return device;
}
static struct ib_device *__ib_device_get_by_name(const char *name)
{
struct ib_device *device;

54
drivers/infiniband/core/nldev.c
View File

@ -142,27 +142,34 @@ static int nldev_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
device = __ib_device_get_by_index(index);
device = ib_device_get_by_index(index);
if (!device)
return -EINVAL;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
if (!msg) {
err = -ENOMEM;
goto err;
}
nlh = nlmsg_put(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq,
RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_GET),
0, 0);
err = fill_dev_info(msg, device);
if (err) {
nlmsg_free(msg);
return err;
}
if (err)
goto err_free;
nlmsg_end(msg, nlh);
put_device(&device->dev);
return rdma_nl_unicast(msg, NETLINK_CB(skb).portid);
err_free:
nlmsg_free(msg);
err:
put_device(&device->dev);
return err;
}
static int _nldev_get_dumpit(struct ib_device *device,
@ -220,31 +227,40 @@ static int nldev_port_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
return -EINVAL;
index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
device = __ib_device_get_by_index(index);
device = ib_device_get_by_index(index);
if (!device)
return -EINVAL;
port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
if (!rdma_is_port_valid(device, port))
return -EINVAL;
if (!rdma_is_port_valid(device, port)) {
err = -EINVAL;
goto err;
}
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
if (!msg) {
err = -ENOMEM;
goto err;
}
nlh = nlmsg_put(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq,
RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_GET),
0, 0);
err = fill_port_info(msg, device, port);
if (err) {
nlmsg_free(msg);
return err;
}
if (err)
goto err_free;
nlmsg_end(msg, nlh);
put_device(&device->dev);
return rdma_nl_unicast(msg, NETLINK_CB(skb).portid);
err_free:
nlmsg_free(msg);
err:
put_device(&device->dev);
return err;
}
static int nldev_port_get_dumpit(struct sk_buff *skb,
@ -265,7 +281,7 @@ static int nldev_port_get_dumpit(struct sk_buff *skb,
return -EINVAL;
ifindex = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
device = __ib_device_get_by_index(ifindex);
device = ib_device_get_by_index(ifindex);
if (!device)
return -EINVAL;
@ -299,7 +315,9 @@ static int nldev_port_get_dumpit(struct sk_buff *skb,
nlmsg_end(skb, nlh);
}
out: cb->args[0] = idx;
out:
put_device(&device->dev);
cb->args[0] = idx;
return skb->len;
}