lkml.org 
[lkml]   [2018]   [Feb]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH AUTOSEL for 4.14 081/110] RDMA/netlink: Fix locking around __ib_get_device_by_index
Date
From: Leon Romanovsky <leonro@mellanox.com>

[ 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@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
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(-)

diff --git a/drivers/infiniband/core/core_priv.h b/drivers/infiniband/core/core_priv.h
index a1d687a664f8..66f0268f37a6 100644
--- a/drivers/infiniband/core/core_priv.h
+++ b/drivers/infiniband/core/core_priv.h
@@ -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);
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 84fc32a2c8b3..f65f64cb8455 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 2fae850a3eff..4fbb9681f5cf 100644
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -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;
}

--
2.11.0
\
 
 \ /
  Last update: 2018-02-03 19:47    [W:0.600 / U:4.020 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site