Use neighbour lock when copying MAC address from neighbour data struct in dst_fetch_ha.
When not using the lock, it is possible for the function to race with neigh_update, causing it to copy an invalid MAC address. It is possible to provoke this error by calling rdma_resolve_addr in a tight loop, while deleting the corresponding ARP entry in another tight loop. Signed-off-by: Dag Moxnes <[email protected]> Change-Id: I3c5f982b304457f0a83ea7def2fac70315ed38b4 --- drivers/infiniband/core/addr.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c index 2f7d141598..e4945fd1bb 100644 --- a/drivers/infiniband/core/addr.c +++ b/drivers/infiniband/core/addr.c @@ -333,12 +333,16 @@ static int dst_fetch_ha(const struct dst_entry *dst, if (!n) return -ENODATA; + read_lock_bh(&n->lock) if (!(n->nud_state & NUD_VALID)) { - neigh_event_send(n, NULL); ret = -ENODATA; } else { memcpy(dev_addr->dst_dev_addr, n->ha, MAX_ADDR_LEN); } + read_unlock_bh(&n->lock); + + if (ret) + neigh_event_send(n, NULL); neigh_release(n); -- 2.20.1
