From: Zhantao Fu <[email protected]> Now the subtable in classifier/dpcls is postponed by destroy_subtable before move itself out of cls->subtables(pvector).It will raise use-after-free problem.
use double postponing to free subtable Signed-off-by: Zhantao Fu <[email protected]> --- lib/classifier.c | 29 +++++++++++++++++++---------- lib/dpif-netdev.c | 10 ++++++++-- 2 files changed, 27 insertions(+), 12 deletions(-) diff --git a/lib/classifier.c b/lib/classifier.c index edb40c8..10370ce 100644 --- a/lib/classifier.c +++ b/lib/classifier.c @@ -1468,6 +1468,24 @@ miniflow_get_map_in_range(const struct miniflow *miniflow, uint8_t start, return map; } +static void +subtable_destroy_cb(struct cls_subtable *subtable) +{ + int i; + + ovs_assert(ovsrcu_get_protected(struct trie_node *, &subtable->ports_trie) + == NULL); + ovs_assert(cmap_is_empty(&subtable->rules)); + ovs_assert(rculist_is_empty(&subtable->rules_list)); + + for (i = 0; i < subtable->n_indices; i++) { + ccmap_destroy(&subtable->indices[i]); + } + cmap_destroy(&subtable->rules); + + ovsrcu_postpone(free, subtable); +} + /* The new subtable will be visible to the readers only after this. */ static struct cls_subtable * insert_subtable(struct classifier *cls, const struct minimask *mask) @@ -1540,16 +1558,7 @@ destroy_subtable(struct classifier *cls, struct cls_subtable *subtable) cmap_remove(&cls->subtables_map, &subtable->cmap_node, minimask_hash(&subtable->mask, 0)); - ovs_assert(ovsrcu_get_protected(struct trie_node *, &subtable->ports_trie) - == NULL); - ovs_assert(cmap_is_empty(&subtable->rules)); - ovs_assert(rculist_is_empty(&subtable->rules_list)); - - for (i = 0; i < subtable->n_indices; i++) { - ccmap_destroy(&subtable->indices[i]); - } - cmap_destroy(&subtable->rules); - ovsrcu_postpone(free, subtable); + ovsrcu_postpone(subtable_destroy_cb, subtable); } static unsigned int be_get_bit_at(const ovs_be32 value[], unsigned int ofs); diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c index 4d6d0c3..8657a61 100644 --- a/lib/dpif-netdev.c +++ b/lib/dpif-netdev.c @@ -7592,6 +7592,13 @@ struct dpcls_subtable { /* 'mask' must be the last field, additional space is allocated here. */ }; +static void +dpcls_subtable_destroy_cb(struct dpcls_subtable *subtable) +{ + cmap_destroy(&subtable->rules); + ovsrcu_postpone(free, subtable); +} + /* Initializes 'cls' as a classifier that initially contains no classification * rules. */ static void @@ -7608,8 +7615,7 @@ dpcls_destroy_subtable(struct dpcls *cls, struct dpcls_subtable *subtable) pvector_remove(&cls->subtables, subtable); cmap_remove(&cls->subtables_map, &subtable->cmap_node, subtable->mask.hash); - cmap_destroy(&subtable->rules); - ovsrcu_postpone(free, subtable); + ovsrcu_postpone(dpcls_subtable_destroy_cb, subtable); } /* Destroys 'cls'. Rules within 'cls', if any, are not freed; this is the -- 1.9.5.msysgit.1 _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
