batman-adv: Merge bugfixes from 2020.1

* fix batadv_nc_random_weight_tq
* Fix refcnt leak in batadv_show_throughput_override
* Fix refcnt leak in batadv_store_throughput_override
* Fix refcnt leak in batadv_v_ogm_process

Signed-off-by: Sven Eckelmann <sven@narfation.org>

batman-adv/Makefile

@@ -10,7 +10,7 @@ include $(TOPDIR)/rules.mk
 PKG_NAME:=batman-adv
 
 PKG_VERSION:=2018.1
-PKG_RELEASE:=10
+PKG_RELEASE:=11
 PKG_HASH:=b866b28dbbe5c9238abbdf5abbc30fc526dea56898ce4c1bd76d5c017843048b
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz

batman-adv/patches/0042-batman-adv-fix-batadv_nc_random_weight_tq.patch

@@ -0,0 +1,59 @@
+From: George Spelvin <lkml@sdf.org>
+Date: Sun, 8 Mar 2020 09:44:59 -0400
+Subject: batman-adv: fix batadv_nc_random_weight_tq
+
+and change to pseudorandom numbers, as this is a traffic dithering
+operation that doesn't need crypto-grade.
+
+The previous code operated in 4 steps:
+
+1. Generate a random byte 0 <= rand_tq <= 255
+2. Multiply it by BATADV_TQ_MAX_VALUE - tq
+3. Divide by 255 (= BATADV_TQ_MAX_VALUE)
+4. Return BATADV_TQ_MAX_VALUE - rand_tq
+
+This would apperar to scale (BATADV_TQ_MAX_VALUE - tq) by a random
+value between 0/255 and 255/255.
+
+But!  The intermediate value between steps 3 and 4 is stored in a u8
+variable.  So it's truncated, and most of the time, is less than 255, after
+which the division produces 0.  Specifically, if tq is odd, the product is
+always even, and can never be 255.  If tq is even, there's exactly one
+random byte value that will produce a product byte of 255.
+
+Thus, the return value is 255 (511/512 of the time) or 254 (1/512
+of the time).
+
+If we assume that the truncation is a bug, and the code is meant to scale
+the input, a simpler way of looking at it is that it's returning a random
+value between tq and BATADV_TQ_MAX_VALUE, inclusive.
+
+Well, we have an optimized function for doing just that.
+
+Fixes: c3289f3650d3 ("batman-adv: network coding - code and transmit packets if possible")
+Signed-off-by: George Spelvin <lkml@sdf.org>
+Signed-off-by: Sven Eckelmann <sven@narfation.org>
+
+Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/db48c60b0edb995450ee846157364bd09bb23762
+
+diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c
+index 34caf129a9bf5531360f798be6a7059bad26a50f..7f1be5a287575d51ffd5b4e7ecf540b8fd7de700 100644
+--- a/net/batman-adv/network-coding.c
++++ b/net/batman-adv/network-coding.c
+@@ -1021,15 +1021,8 @@ static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv,
+  */
+ static u8 batadv_nc_random_weight_tq(u8 tq)
+ {
+-	u8 rand_val, rand_tq;
+-
+-	get_random_bytes(&rand_val, sizeof(rand_val));
+-
+ 	/* randomize the estimated packet loss (max TQ - estimated TQ) */
+-	rand_tq = rand_val * (BATADV_TQ_MAX_VALUE - tq);
+-
+-	/* normalize the randomized packet loss */
+-	rand_tq /= BATADV_TQ_MAX_VALUE;
++	u8 rand_tq = prandom_u32_max(BATADV_TQ_MAX_VALUE + 1 - tq);
+ 
+ 	/* convert to (randomized) estimated tq again */
+ 	return BATADV_TQ_MAX_VALUE - rand_tq;

batman-adv/patches/0043-batman-adv-Fix-refcnt-leak-in-batadv_show_throughput.patch

@@ -0,0 +1,38 @@
+From: Xiyu Yang <xiyuyang19@fudan.edu.cn>
+Date: Wed, 15 Apr 2020 16:31:50 +0800
+Subject: batman-adv: Fix refcnt leak in batadv_show_throughput_override
+
+batadv_show_throughput_override() invokes batadv_hardif_get_by_netdev(),
+which gets a batadv_hard_iface object from net_dev with increased refcnt
+and its reference is assigned to a local pointer 'hard_iface'.
+
+When batadv_show_throughput_override() returns, "hard_iface" becomes
+invalid, so the refcount should be decreased to keep refcount balanced.
+
+The issue happens in the normal path of
+batadv_show_throughput_override(), which forgets to decrease the refcnt
+increased by batadv_hardif_get_by_netdev() before the function returns,
+causing a refcnt leak.
+
+Fix this issue by calling batadv_hardif_put() before the
+batadv_show_throughput_override() returns in the normal path.
+
+Fixes: c513176e4b7a ("batman-adv: add throughput override attribute to hard_ifaces")
+Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
+Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
+Signed-off-by: Sven Eckelmann <sven@narfation.org>
+
+Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/f301bfed59b146a63471d0f147b767d7cafede6f
+
+diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c
+index 09427fc6494a157554d8b19f3481a878a9f97bba..7f7de0b16aa7ab70986735fbd9b42fd02de8a924 100644
+--- a/net/batman-adv/sysfs.c
++++ b/net/batman-adv/sysfs.c
+@@ -1126,6 +1126,7 @@ static ssize_t batadv_show_throughput_override(struct kobject *kobj,
+ 
+ 	tp_override = atomic_read(&hard_iface->bat_v.throughput_override);
+ 
++	batadv_hardif_put(hard_iface);
+ 	return sprintf(buff, "%u.%u MBit\n", tp_override / 10,
+ 		       tp_override % 10);
+ }

batman-adv/patches/0044-batman-adv-Fix-refcnt-leak-in-batadv_store_throughpu.patch

@@ -0,0 +1,39 @@
+From: Xiyu Yang <xiyuyang19@fudan.edu.cn>
+Date: Wed, 15 Apr 2020 16:35:21 +0800
+Subject: batman-adv: Fix refcnt leak in batadv_store_throughput_override
+
+batadv_show_throughput_override() invokes batadv_hardif_get_by_netdev(),
+which gets a batadv_hard_iface object from net_dev with increased refcnt
+and its reference is assigned to a local pointer 'hard_iface'.
+
+When batadv_store_throughput_override() returns, "hard_iface" becomes
+invalid, so the refcount should be decreased to keep refcount balanced.
+
+The issue happens in one error path of
+batadv_store_throughput_override(). When batadv_parse_throughput()
+returns NULL, the refcnt increased by batadv_hardif_get_by_netdev() is
+not decreased, causing a refcnt leak.
+
+Fix this issue by jumping to "out" label when batadv_parse_throughput()
+returns NULL.
+
+Fixes: c513176e4b7a ("batman-adv: add throughput override attribute to hard_ifaces")
+Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
+Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
+Signed-off-by: Sven Eckelmann <sven@narfation.org>
+
+Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/b69cd8bdbfd6fa7e61878c2fa9e6637406f40dd9
+
+diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c
+index 7f7de0b16aa7ab70986735fbd9b42fd02de8a924..976b038e53bf934332a39bad8a5509ca1aac0add 100644
+--- a/net/batman-adv/sysfs.c
++++ b/net/batman-adv/sysfs.c
+@@ -1093,7 +1093,7 @@ static ssize_t batadv_store_throughput_override(struct kobject *kobj,
+ 	ret = batadv_parse_throughput(net_dev, buff, "throughput_override",
+ 				      &tp_override);
+ 	if (!ret)
+-		return count;
++		goto out;
+ 
+ 	old_tp_override = atomic_read(&hard_iface->bat_v.throughput_override);
+ 	if (old_tp_override == tp_override)

batman-adv/patches/0045-batman-adv-Fix-refcnt-leak-in-batadv_v_ogm_process.patch

@@ -0,0 +1,39 @@
+From: Xiyu Yang <xiyuyang19@fudan.edu.cn>
+Date: Mon, 20 Apr 2020 13:37:20 +0800
+Subject: batman-adv: Fix refcnt leak in batadv_v_ogm_process
+
+batadv_v_ogm_process() invokes batadv_hardif_neigh_get(), which returns
+a reference of the neighbor object to "hardif_neigh" with increased
+refcount.
+
+When batadv_v_ogm_process() returns, "hardif_neigh" becomes invalid, so
+the refcount should be decreased to keep refcount balanced.
+
+The reference counting issue happens in one exception handling paths of
+batadv_v_ogm_process(). When batadv_v_ogm_orig_get() fails to get the
+orig node and returns NULL, the refcnt increased by
+batadv_hardif_neigh_get() is not decreased, causing a refcnt leak.
+
+Fix this issue by jumping to "out" label when batadv_v_ogm_orig_get()
+fails to get the orig node.
+
+Fixes: 667996ebeab4 ("batman-adv: OGMv2 - implement originators logic")
+Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
+Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
+Signed-off-by: Sven Eckelmann <sven@narfation.org>
+
+Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/4515f5e6a4ccbe1c563b05f2d487eb9eef3c9740
+
+diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c
+index bf9ea404abe7cbe1dd2113881856cd35b718b7d1..0458de53cb64b2da51de492ffa27f33068351cc8 100644
+--- a/net/batman-adv/bat_v_ogm.c
++++ b/net/batman-adv/bat_v_ogm.c
+@@ -735,7 +735,7 @@ static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
+ 
+ 	orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
+ 	if (!orig_node)
+-		return;
++		goto out;
+ 
+ 	neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
+ 						     ethhdr->h_source);