lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [day] [month] [year] [list]
Message-Id: <20190627003616.20767-31-sashal@kernel.org>
Date:   Wed, 26 Jun 2019 20:35:46 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Jonathan Lemon <jonathan.lemon@...il.com>,
        Martin KaFai Lau <kafai@...com>,
        Daniel Borkmann <daniel@...earbox.net>,
        Sasha Levin <sashal@...nel.org>, netdev@...r.kernel.org,
        bpf@...r.kernel.org, linux-kselftest@...r.kernel.org
Subject: [PATCH AUTOSEL 4.19 31/60] bpf: lpm_trie: check left child of last leftmost node for NULL

From: Jonathan Lemon <jonathan.lemon@...il.com>

[ Upstream commit da2577fdd0932ea4eefe73903f1130ee366767d2 ]

If the leftmost parent node of the tree has does not have a child
on the left side, then trie_get_next_key (and bpftool map dump) will
not look at the child on the right.  This leads to the traversal
missing elements.

Lookup is not affected.

Update selftest to handle this case.

Reproducer:

 bpftool map create /sys/fs/bpf/lpm type lpm_trie key 6 \
     value 1 entries 256 name test_lpm flags 1
 bpftool map update pinned /sys/fs/bpf/lpm key  8 0 0 0  0   0 value 1
 bpftool map update pinned /sys/fs/bpf/lpm key 16 0 0 0  0 128 value 2
 bpftool map dump   pinned /sys/fs/bpf/lpm

Returns only 1 element. (2 expected)

Fixes: b471f2f1de8b ("bpf: implement MAP_GET_NEXT_KEY command for LPM_TRIE")
Signed-off-by: Jonathan Lemon <jonathan.lemon@...il.com>
Acked-by: Martin KaFai Lau <kafai@...com>
Signed-off-by: Daniel Borkmann <daniel@...earbox.net>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 kernel/bpf/lpm_trie.c                      |  9 +++--
 tools/testing/selftests/bpf/test_lpm_map.c | 41 ++++++++++++++++++++--
 2 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
index 4f3138e6ecb2..1a8b208f6c55 100644
--- a/kernel/bpf/lpm_trie.c
+++ b/kernel/bpf/lpm_trie.c
@@ -676,9 +676,14 @@ static int trie_get_next_key(struct bpf_map *map, void *_key, void *_next_key)
 	 * have exact two children, so this function will never return NULL.
 	 */
 	for (node = search_root; node;) {
-		if (!(node->flags & LPM_TREE_NODE_FLAG_IM))
+		if (node->flags & LPM_TREE_NODE_FLAG_IM) {
+			node = rcu_dereference(node->child[0]);
+		} else {
 			next_node = node;
-		node = rcu_dereference(node->child[0]);
+			node = rcu_dereference(node->child[0]);
+			if (!node)
+				node = rcu_dereference(next_node->child[1]);
+		}
 	}
 do_copy:
 	next_key->prefixlen = next_node->prefixlen;
diff --git a/tools/testing/selftests/bpf/test_lpm_map.c b/tools/testing/selftests/bpf/test_lpm_map.c
index 02d7c871862a..006be3963977 100644
--- a/tools/testing/selftests/bpf/test_lpm_map.c
+++ b/tools/testing/selftests/bpf/test_lpm_map.c
@@ -573,13 +573,13 @@ static void test_lpm_get_next_key(void)
 
 	/* add one more element (total two) */
 	key_p->prefixlen = 24;
-	inet_pton(AF_INET, "192.168.0.0", key_p->data);
+	inet_pton(AF_INET, "192.168.128.0", key_p->data);
 	assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0);
 
 	memset(key_p, 0, key_size);
 	assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0);
 	assert(key_p->prefixlen == 24 && key_p->data[0] == 192 &&
-	       key_p->data[1] == 168 && key_p->data[2] == 0);
+	       key_p->data[1] == 168 && key_p->data[2] == 128);
 
 	memset(next_key_p, 0, key_size);
 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
@@ -592,7 +592,7 @@ static void test_lpm_get_next_key(void)
 
 	/* Add one more element (total three) */
 	key_p->prefixlen = 24;
-	inet_pton(AF_INET, "192.168.128.0", key_p->data);
+	inet_pton(AF_INET, "192.168.0.0", key_p->data);
 	assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0);
 
 	memset(key_p, 0, key_size);
@@ -643,6 +643,41 @@ static void test_lpm_get_next_key(void)
 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == -1 &&
 	       errno == ENOENT);
 
+	/* Add one more element (total five) */
+	key_p->prefixlen = 28;
+	inet_pton(AF_INET, "192.168.1.128", key_p->data);
+	assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0);
+
+	memset(key_p, 0, key_size);
+	assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0);
+	assert(key_p->prefixlen == 24 && key_p->data[0] == 192 &&
+	       key_p->data[1] == 168 && key_p->data[2] == 0);
+
+	memset(next_key_p, 0, key_size);
+	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
+	assert(next_key_p->prefixlen == 28 && next_key_p->data[0] == 192 &&
+	       next_key_p->data[1] == 168 && next_key_p->data[2] == 1 &&
+	       next_key_p->data[3] == 128);
+
+	memcpy(key_p, next_key_p, key_size);
+	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
+	assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 &&
+	       next_key_p->data[1] == 168 && next_key_p->data[2] == 1);
+
+	memcpy(key_p, next_key_p, key_size);
+	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
+	assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 &&
+	       next_key_p->data[1] == 168 && next_key_p->data[2] == 128);
+
+	memcpy(key_p, next_key_p, key_size);
+	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
+	assert(next_key_p->prefixlen == 16 && next_key_p->data[0] == 192 &&
+	       next_key_p->data[1] == 168);
+
+	memcpy(key_p, next_key_p, key_size);
+	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == -1 &&
+	       errno == ENOENT);
+
 	/* no exact matching key should return the first one in post order */
 	key_p->prefixlen = 22;
 	inet_pton(AF_INET, "192.168.1.0", key_p->data);
-- 
2.20.1

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ