This is a note to let you know that I've just added the patch titled
RDMA/netlink: Fix locking around __ib_get_device_by_index
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
rdma-netlink-fix-locking-around-__ib_get_device_by_index.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Feb 28 16:23:28 CET 2018
From: Leon Romanovsky <leonro@xxxxxxxxxxxx>
Date: Mon, 1 Jan 2018 13:07:15 +0200
Subject: RDMA/netlink: Fix locking around __ib_get_device_by_index
From: Leon Romanovsky <leonro@xxxxxxxxxxxx>
[ Upstream commit f8978bd95cf92f869f3d9b34c1b699f49253b8c6 ]
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>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/infiniband/core/core_priv.h | 2 -
drivers/infiniband/core/device.c | 18 +++++++++++-
drivers/infiniband/core/nldev.c | 54 ++++++++++++++++++++++++------------
3 files changed, 54 insertions(+), 20 deletions(-)
--- a/drivers/infiniband/core/core_priv.h
+++ b/drivers/infiniband/core/core_priv.h
@@ -314,7 +314,7 @@ static inline int ib_mad_enforce_securit
}
#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);
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -134,7 +134,7 @@ static int ib_device_check_mandatory(str
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_ind
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;
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -142,27 +142,34 @@ static int nldev_get_doit(struct sk_buff
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
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
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
nlmsg_end(skb, nlh);
}
-out: cb->args[0] = idx;
+out:
+ put_device(&device->dev);
+ cb->args[0] = idx;
return skb->len;
}
Patches currently in stable-queue which might be from leonro@xxxxxxxxxxxx are
queue-4.14/ib-mlx4-fix-mlx4_ib_alloc_mr-error-flow.patch
queue-4.14/rdma-netlink-fix-locking-around-__ib_get_device_by_index.patch