tcp: metrics: Fix rcu-race when deleting multiple entries

In bbf852b96ebdc6d1 I introduced the tmlist, which allows to delete
multiple entries from the cache that match a specified destination if no
source-IP is specified.

However, as the cache is an RCU-list, we should not create this tmlist, as
it will change the tcpm_next pointer of the element that will be deleted
and so a thread iterating over the cache's entries while holding the
RCU-lock might get "redirected" to this tmlist.

This patch fixes this, by reverting back to the old behavior prior to
bbf852b96ebdc6d1, which means that we simply change the tcpm_next
pointer of the previous element (pp) to jump over the one we are
deleting.
The difference is that we call kfree_rcu() directly on the cache entry,
which allows us to delete multiple entries from the list.

Fixes: bbf852b96ebdc6d1 (tcp: metrics: Delete all entries matching a certain destination)
Signed-off-by: Christoph Paasch <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions