[ Upstream commit 4e7aaa6b82d63e8ddcbfb56b4fd3d014ca586f10 ]
Lion Ackermann reported that there is a race condition between namespace cleanup
in ipset and the garbage collection of the list:set type. The namespace
cleanup can destroy the list:set type of sets while the gc of the set type is
waiting to run in rcu cleanup. The latter uses data from the destroyed set which
thus leads use after free. The patch contains the following parts:
- When destroying all sets, first remove the garbage collectors, then wait
if needed and then destroy the sets.
- Fix the badly ordered "wait then remove gc" for the destroy a single set
case.
- Fix the missing rcu locking in the list:set type in the userspace test
case.
- Use proper RCU list handlings in the list:set type.
The patch depends on c1193d9bbbd3 (netfilter: ipset: Add list flush to cancel_gc).
Fixes: 97f7cf1cd80e (netfilter: ipset: fix performance regression in swap operation)
Reported-by: Lion Ackermann <nnamrec@gmail.com>
Tested-by: Lion Ackermann <nnamrec@gmail.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2ba35b37f7