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author | Nikolay Borisov <kernel@kyup.com> | 2015-10-16 09:40:28 +0300 |
---|---|---|
committer | Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> | 2015-10-16 13:55:31 +0200 |
commit | e3f1193c8293731038bdbe98266636ab67f2a162 (patch) | |
tree | 7f56cff8420010ed2dee05f466a4e07f70a23c21 | |
parent | fee1393643f9d2b2d72d6395bd021421b120dc50 (diff) | |
download | ipset-e3f1193c8293731038bdbe98266636ab67f2a162.tar.gz |
netfilter: ipset: Fix sleeping memory allocation in atomic context
Commit 00590fdd5be0 introduced RCU locking in list type and in
doing so introduced a memory allocation in list_set_add, which
is done in an atomic context, due to the fact that ipset rcu
list modifications are serialised with a spin lock. The reason
why we can't use a mutex is that in addition to modifying the
list with ipset commands, it's also being modified when a
particular ipset rule timeout expires aka garbage collection.
This gc is triggered from set_cleanup_entries, which in turn
is invoked from a timer thus requiring the lock to be bh-safe.
Concretely the following call chain can lead to "sleeping function
called in atomic context" splat:
call_ad -> list_set_uadt -> list_set_uadd -> kzalloc(, GFP_KERNEL).
And since GFP_KERNEL allows initiating direct reclaim thus
potentially sleeping in the allocation path.
To fix the issue change the allocation type to GFP_ATOMIC, to
correctly reflect that it is occuring in an atomic context.
Fixes: 00590fdd5be0 ("netfilter: ipset: Introduce RCU locking in list type")
Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
-rw-r--r-- | kernel/net/netfilter/ipset/ip_set_list_set.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/net/netfilter/ipset/ip_set_list_set.c b/kernel/net/netfilter/ipset/ip_set_list_set.c index b11ba96..0f9195f 100644 --- a/kernel/net/netfilter/ipset/ip_set_list_set.c +++ b/kernel/net/netfilter/ipset/ip_set_list_set.c @@ -298,7 +298,7 @@ list_set_uadd(struct ip_set *set, void *value, const struct ip_set_ext *ext, ip_set_timeout_expired(ext_timeout(n, set)))) n = NULL; - e = kzalloc(set->dsize, GFP_KERNEL); + e = kzalloc(set->dsize, GFP_ATOMIC); if (!e) return -ENOMEM; e->id = d->id; |