-----"Jason Gunthorpe" <jgg@xxxxxxxx> wrote: -----
>To: "Bernard Metzler" <bmt@xxxxxxxxxxxxxx>
>From: "Jason Gunthorpe" <jgg@xxxxxxxx>
>Date: 08/27/2019 07:28PM
>Cc: linux-rdma@xxxxxxxxxxxxxxx, bvanassche@xxxxxxx,
>dledford@xxxxxxxxxx
>Subject: [EXTERNAL] Re: [PATCH v2] RDMA/siw: Fix IPv6 addr_list
>locking
>
>On Tue, Aug 27, 2019 at 06:49:55PM +0200, Bernard Metzler wrote:
>> Walking the address list of an inet6_dev requires
>> appropriate locking. Since the called function
>> siw_listen_address() may sleep, we have to use
>> rtnl_lock() instead of read_lock_bh().
>>
>> Also introduces:
>> - sanity checks if we got a device from
>> in_dev_get() or in6_dev_get().
>> - skipping IPv6 addresses flagged IFA_F_TENTATIVE
>> or IFA_F_DEPRECATED
>>
>> Reported-by: Bart Van Assche <bvanassche@xxxxxxx>
>> Fixes: 6c52fdc244b5 ("rdma/siw: connection management")
>> Signed-off-by: Bernard Metzler <bmt@xxxxxxxxxxxxxx>
>> drivers/infiniband/sw/siw/siw_cm.c | 33
>+++++++++++++++++++-----------
>> 1 file changed, 21 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/infiniband/sw/siw/siw_cm.c
>b/drivers/infiniband/sw/siw/siw_cm.c
>> index 1db5ad3d9580..c145b4ff4556 100644
>> +++ b/drivers/infiniband/sw/siw/siw_cm.c
>> @@ -1962,6 +1962,10 @@ int siw_create_listen(struct iw_cm_id *id,
>int backlog)
>> struct sockaddr_in s_laddr, *s_raddr;
>> const struct in_ifaddr *ifa;
>>
>> + if (!in_dev) {
>> + rv = -ENODEV;
>> + goto out;
>> + }
>> memcpy(&s_laddr, &id->local_addr, sizeof(s_laddr));
>> s_raddr = (struct sockaddr_in *)&id->remote_addr;
>>
>> @@ -1991,22 +1995,27 @@ int siw_create_listen(struct iw_cm_id *id,
>int backlog)
>> struct sockaddr_in6 *s_laddr = &to_sockaddr_in6(id->local_addr),
>> *s_raddr = &to_sockaddr_in6(id->remote_addr);
>>
>> + if (!in6_dev) {
>> + rv = -ENODEV;
>> + goto out;
>> + }
>> siw_dbg(id->device,
>> "laddr %pI6:%d, raddr %pI6:%d\n",
>> &s_laddr->sin6_addr, ntohs(s_laddr->sin6_port),
>> &s_raddr->sin6_addr, ntohs(s_raddr->sin6_port));
>>
>> - read_lock_bh(&in6_dev->lock);
>> - list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
>> - struct sockaddr_in6 bind_addr;
>> -
>> + rtnl_lock();
>> + list_for_each_entry_rcu(ifp, &in6_dev->addr_list, if_list) {
>
>If not holding RCU then don't use the rcu list iterator..
>
absolutely!
