On Mon, Jan 01, 2018 at 01:07:16PM +0200, Leon Romanovsky wrote:
> diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
> index 34c6cb2a0977..a0ea3dca479d 100644
> +++ b/drivers/infiniband/core/device.c
> @@ -134,7 +134,10 @@ static int ib_device_check_mandatory(struct ib_device *device)
> return 0;
> }
>
> -struct ib_device *__ib_device_get_by_index(u32 index)
> +/*
> + * Caller to this function should hold lists_rwsem
> + */
This comment isn't 100% right, the device mutex is also OK to hold, I
dropped it.
> @@ -141,36 +141,41 @@ static int nldev_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
> struct ib_device *device;
> struct sk_buff *msg;
> u32 index;
> - int err;
> + int ret = -ENOMEM;
>
> - err = nlmsg_parse(nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1,
> + ret = nlmsg_parse(nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1,
> nldev_policy, extack);
Initializing ret, then overwriting it with nlmsg_parse is silly, and
leads to this bug:
> msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
> if (!msg)
> - return -ENOMEM;
> + goto err;
Wrong return code after the change.
I fixed it also dropped replacing err with ret since this is probably
going to be backported.
> port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
> if (!rdma_is_port_valid(device, port))
> - return -EINVAL;
> + goto err;
Same mistake again
I also squashed this with the prior patch to make backporting simpler
RDMA/core: Provide locked variant of device name to index function
And queued it to for-rc
See below, please check my work.
Author: Leon Romanovsky <leonro@xxxxxxxxxxxx>
Date: Mon Jan 1 13:07:15 2018 +0200
RDMA/netlink: Fix locking around __ib_get_device_by_index
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: e5c9469efcb1 ("RDMA/netlink: Add nldev device doit implementation")
Fixes: c3f66f7b0052 ("RDMA/netlink: Implement nldev port doit callback")
Fixes: 7d02f605f0dc ("RDMA/netlink: Add nldev port dumpit implementation")
Reviewed-by: Mark Bloch <markb@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
diff --git a/drivers/infiniband/core/core_priv.h b/drivers/infiniband/core/core_priv.h
index 0deff4c4911b2b..8dbfc3ab48a608 100644
--- a/drivers/infiniband/core/core_priv.h
+++ b/drivers/infiniband/core/core_priv.h
@@ -294,7 +294,7 @@ 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);
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index a8757b5552de1d..1b413a2df9489b 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -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;
diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
index 2b631307349ddc..5d790c507c7e17 100644
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -150,27 +150,34 @@ 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,
@@ -228,31 +235,40 @@ 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,
@@ -273,7 +289,7 @@ 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;
@@ -307,7 +323,9 @@ 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;
}
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