| Message ID | 1391778947-8957-2-git-send-email-pablo@netfilter.org |
|---|---|
| State | Accepted |
| Headers | show |
On Fri, Feb 07, 2014 at 02:15:47PM +0100, Pablo Neira Ayuso wrote: > This patch fixes several things which related to the handling of > end interval elements: > > * Chain use underflow with intervals and map: If you add a rule > using intervals+map that introduces a loop, the error path of the > rbtree set decrements the chain refcount for each side of the > interval, leading to a chain use counter underflow. > > * Don't copy the data part of the end interval element since, this > area is uninitialized and this confuses the loop detection code. > > * Don't allocate room for the data part of end interval elements > since this is unused. > > So, after this patch the idea is that end interval elements don't > have a data part. > > Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> > --- > This patch extends http://patchwork.ozlabs.org/patch/317485/. > > @Patrick, you mentioned also that nft_hash needs to be adjusted, but > after looking at this again I think there's no problem there since > hash cannot currently be selected for interval sets. Thanks for your > comments on the initial patch :) Correct, just noticed that myself :) Acked-by: Patrick McHardy <kaber@trash.net> for both patches. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/netfilter/nft_rbtree.c b/net/netfilter/nft_rbtree.c index ca0c1b2..e21d69d 100644 --- a/net/netfilter/nft_rbtree.c +++ b/net/netfilter/nft_rbtree.c @@ -69,8 +69,10 @@ static void nft_rbtree_elem_destroy(const struct nft_set *set, struct nft_rbtree_elem *rbe) { nft_data_uninit(&rbe->key, NFT_DATA_VALUE); - if (set->flags & NFT_SET_MAP) + if (set->flags & NFT_SET_MAP && + !(rbe->flags & NFT_SET_ELEM_INTERVAL_END)) nft_data_uninit(rbe->data, set->dtype); + kfree(rbe); } @@ -108,7 +110,8 @@ static int nft_rbtree_insert(const struct nft_set *set, int err; size = sizeof(*rbe); - if (set->flags & NFT_SET_MAP) + if (set->flags & NFT_SET_MAP && + !(elem->flags & NFT_SET_ELEM_INTERVAL_END)) size += sizeof(rbe->data[0]); rbe = kzalloc(size, GFP_KERNEL); @@ -117,7 +120,8 @@ static int nft_rbtree_insert(const struct nft_set *set, rbe->flags = elem->flags; nft_data_copy(&rbe->key, &elem->key); - if (set->flags & NFT_SET_MAP) + if (set->flags & NFT_SET_MAP && + !(rbe->flags & NFT_SET_ELEM_INTERVAL_END)) nft_data_copy(rbe->data, &elem->data); err = __nft_rbtree_insert(set, rbe); @@ -153,7 +157,8 @@ static int nft_rbtree_get(const struct nft_set *set, struct nft_set_elem *elem) parent = parent->rb_right; else { elem->cookie = rbe; - if (set->flags & NFT_SET_MAP) + if (set->flags & NFT_SET_MAP && + !(rbe->flags & NFT_SET_ELEM_INTERVAL_END)) nft_data_copy(&elem->data, rbe->data); elem->flags = rbe->flags; return 0; @@ -177,7 +182,8 @@ static void nft_rbtree_walk(const struct nft_ctx *ctx, rbe = rb_entry(node, struct nft_rbtree_elem, node); nft_data_copy(&elem.key, &rbe->key); - if (set->flags & NFT_SET_MAP) + if (set->flags & NFT_SET_MAP && + !(rbe->flags & NFT_SET_ELEM_INTERVAL_END)) nft_data_copy(&elem.data, rbe->data); elem.flags = rbe->flags;
This patch fixes several things which related to the handling of end interval elements: * Chain use underflow with intervals and map: If you add a rule using intervals+map that introduces a loop, the error path of the rbtree set decrements the chain refcount for each side of the interval, leading to a chain use counter underflow. * Don't copy the data part of the end interval element since, this area is uninitialized and this confuses the loop detection code. * Don't allocate room for the data part of end interval elements since this is unused. So, after this patch the idea is that end interval elements don't have a data part. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- This patch extends http://patchwork.ozlabs.org/patch/317485/. @Patrick, you mentioned also that nft_hash needs to be adjusted, but after looking at this again I think there's no problem there since hash cannot currently be selected for interval sets. Thanks for your comments on the initial patch :) net/netfilter/nft_rbtree.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)