From 935454915c3387d7679375ad8386fa3f6401db8b Mon Sep 17 00:00:00 2001 From: Leon Romanovsky Date: Mon, 1 Jan 2018 13:07:15 +0200 Subject: [PATCH] RDMA/netlink: Fix locking around __ib_get_device_by_index [ 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 Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- 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 a1d687a..66f0268 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 b4b28ff..d7d042a 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 9a05245..0dcd1aa 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; } -- 2.7.4