From: Christoph Paasch Date: Tue, 21 Jan 2014 12:30:26 +0000 (+0100) Subject: tcp: metrics: Fix rcu-race when deleting multiple entries X-Git-Tag: v3.14-rc1~94^2~34 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=00ca9c5b2b11d44eaf20a4b647efc999734323ec;p=pandora-kernel.git 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 Signed-off-by: David S. Miller --- Reading git-diff-tree failed