add fix for DoS via nftables

This commit is contained in:
Fabian Grünbichler 2017-05-22 09:59:35 +02:00
parent 0f0062b520
commit 88582bb094
2 changed files with 55 additions and 0 deletions

View file

@ -0,0 +1,54 @@
From 6fa9fc0ce1032710ce017c444b0c66eaf9e77782 Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Mon, 22 May 2017 00:17:30 +0200
Subject: [PATCH linux] netfilter: nft_set_rbtree: handle re-addition element
after deletion
The existing code selects no next branch to be inspected when
re-inserting an inactive element into the rb-tree, looping endlessly.
This patch restricts the check for active elements to the EEXIST case
only.
Fixes: e701001e7cbe ("netfilter: nft_rbtree: allow adjacent intervals with dynamic updates")
Reported-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/nft_set_rbtree.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c
index f06f55e..51ff879 100644
--- a/net/netfilter/nft_set_rbtree.c
+++ b/net/netfilter/nft_set_rbtree.c
@@ -118,17 +118,17 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
else if (d > 0)
p = &parent->rb_right;
else {
- if (nft_set_elem_active(&rbe->ext, genmask)) {
- if (nft_rbtree_interval_end(rbe) &&
- !nft_rbtree_interval_end(new))
- p = &parent->rb_left;
- else if (!nft_rbtree_interval_end(rbe) &&
- nft_rbtree_interval_end(new))
- p = &parent->rb_right;
- else {
- *ext = &rbe->ext;
- return -EEXIST;
- }
+ if (nft_rbtree_interval_end(rbe) &&
+ !nft_rbtree_interval_end(new)) {
+ p = &parent->rb_left;
+ } else if (!nft_rbtree_interval_end(rbe) &&
+ nft_rbtree_interval_end(new)) {
+ p = &parent->rb_right;
+ } else if (nft_set_elem_active(&rbe->ext, genmask)) {
+ *ext = &rbe->ext;
+ return -EEXIST;
+ } else {
+ p = &parent->rb_left;
}
}
}
--
2.1.4

View file

@ -240,6 +240,7 @@ ${KERNEL_SRC}/README ${KERNEL_CFG_ORG}: ${KERNEL_SRC_SUBMODULE} | submodules
cd ${KERNEL_SRC}; patch -p1 < ../swapops-0002-Revert-mm-ksm-convert-write_protect_page-to-use-page.patch
cd ${KERNEL_SRC}; patch -p1 < ../swapops-0003-Revert-mm-introduce-page_vma_mapped_walk.patch
cd ${KERNEL_SRC}; patch -p1 < ../swapops-0004-mm-ksm-handle-protnone-saved-writes-when-making-page.patch
cd ${KERNEL_SRC}; patch -p1 < ../0001-netfilter-nft_set_rbtree-handle-re-addition-element-.patch # DoS from within (unpriv) containers
sed -i ${KERNEL_SRC}/Makefile -e 's/^EXTRAVERSION.*$$/EXTRAVERSION=${EXTRAVERSION}/'
touch $@