Skip to contentSkip to conversation

FAILED: patch "[PATCH] batman-adv: tt: avoid empty VLAN responses" failed to apply to 6.12-stable tree

PATCH Applied [email protected] 3 participants 3 messages May 28 – Jun 3

Subsystems (2)
lore
Share & tools
lore

[email protected]

author maintainer
#0 lore raw

The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x fa1bd704940b5bcbc32c0b28db9167405c8ee5e0
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026052841-swinging-july-e7e4@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From fa1bd704940b5bcbc32c0b28db9167405c8ee5e0 Mon Sep 17 00:00:00 2001
From: Sven Eckelmann <[email protected]>
Date: Sat, 2 May 2026 20:47:34 +0200
Subject: [PATCH] batman-adv: tt: avoid empty VLAN responses

The commit 16116dac2339 ("batman-adv: prevent TT request storms by not sending inconsistent TT TLVLs") added checks to the local (direct) TT response code. But the response can also be done indirectly by another node using the global TT state. To avoid such inconsistency states reported in the original fix, also avoid sending empty VLANs for replies from the global TT state.

Fixes 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific")
net/batman-adv/translation-table.c +17 -3
index f009cbf8a276..2259b241e0b5 100644
@@ -797,24 +797,26 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node,
 				   s32 *tt_len)
 {
 	u16 num_vlan = 0;
-	u16 num_entries = 0;
 	u16 tvlv_len = 0;
 	unsigned int change_offset;
 	struct batadv_tvlv_tt_vlan_data *tt_vlan;
 	struct batadv_orig_node_vlan *vlan;
+	u16 total_entries = 0;
 	u8 *tt_change_ptr;
+	int vlan_entries;
 
 	spin_lock_bh(&orig_node->vlan_list_lock);
 	hlist_for_each_entry(vlan, &orig_node->vlan_list, list) {
+		vlan_entries = atomic_read(&vlan->tt.num_entries);
+		total_entries += vlan_entries;
 		num_vlan++;
-		num_entries += atomic_read(&vlan->tt.num_entries);
 	}
 
 	change_offset = struct_size(*tt_data, vlan_data, num_vlan);
 
 	/* if tt_len is negative, allocate the space needed by the full table */
 	if (*tt_len < 0)
-		*tt_len = batadv_tt_len(num_entries);
+		*tt_len = batadv_tt_len(total_entries);
 
 	if (change_offset > U16_MAX || *tt_len > U16_MAX - change_offset) {
 		*tt_len = 0;
@@ -835,14 +837,26 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node,
 	(*tt_data)->num_vlan = htons(num_vlan);
 
 	tt_vlan = (*tt_data)->vlan_data;
+	num_vlan = 0;
 	hlist_for_each_entry(vlan, &orig_node->vlan_list, list) {
+		vlan_entries = atomic_read(&vlan->tt.num_entries);
+		if (vlan_entries < 1)
+			continue;
+
 		tt_vlan->vid = htons(vlan->vid);
 		tt_vlan->crc = htonl(vlan->tt.crc);
 		tt_vlan->reserved = 0;
 
 		tt_vlan++;
+		num_vlan++;
 	}
 
+	/* recalculate in case number of VLANs reduced */
+	change_offset = struct_size(*tt_data, vlan_data, num_vlan);
+	tvlv_len = *tt_len + change_offset;
+
+	(*tt_data)->num_vlan = htons(num_vlan);
+
 	tt_change_ptr = (u8 *)*tt_data + change_offset;
 	*tt_change = (struct batadv_tvlv_tt_change *)tt_change_ptr;
 
maintainer
#1 lore raw

PATCH 1/1 batman-adv: tt: avoid empty VLAN responses

commit fa1bd704940b5bcbc32c0b28db9167405c8ee5e0 upstream.

The commit 16116dac2339 ("batman-adv: prevent TT request storms by not sending inconsistent TT TLVLs") added checks to the local (direct) TT response code. But the response can also be done indirectly by another node using the global TT state. To avoid such inconsistency states reported in the original fix, also avoid sending empty VLANs for replies from the global TT state.

Fixes 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific")
[ Context, drop flex array dependency ]
---
 net/batman-adv/translation-table.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)
net/batman-adv/translation-table.c +18 -3
index d4cebe122e528..4045ddefc29b4 100644
@@ -843,17 +843,19 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node,
 				   s32 *tt_len)
 {
 	u16 num_vlan = 0;
-	u16 num_entries = 0;
 	u16 tvlv_len = 0;
 	unsigned int change_offset;
 	struct batadv_tvlv_tt_vlan_data *tt_vlan;
 	struct batadv_orig_node_vlan *vlan;
+	u16 total_entries = 0;
 	u8 *tt_change_ptr;
+	int vlan_entries;
 
 	spin_lock_bh(&orig_node->vlan_list_lock);
 	hlist_for_each_entry(vlan, &orig_node->vlan_list, list) {
+		vlan_entries = atomic_read(&vlan->tt.num_entries);
+		total_entries += vlan_entries;
 		num_vlan++;
-		num_entries += atomic_read(&vlan->tt.num_entries);
 	}
 
 	change_offset = sizeof(**tt_data);
@@ -861,7 +863,7 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node,
 
 	/* if tt_len is negative, allocate the space needed by the full table */
 	if (*tt_len < 0)
-		*tt_len = batadv_tt_len(num_entries);
+		*tt_len = batadv_tt_len(total_entries);
 
 	if (change_offset > U16_MAX || *tt_len > U16_MAX - change_offset) {
 		*tt_len = 0;
@@ -882,14 +884,27 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node,
 	(*tt_data)->num_vlan = htons(num_vlan);
 
 	tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(*tt_data + 1);
+	num_vlan = 0;
 	hlist_for_each_entry(vlan, &orig_node->vlan_list, list) {
+		vlan_entries = atomic_read(&vlan->tt.num_entries);
+		if (vlan_entries < 1)
+			continue;
+
 		tt_vlan->vid = htons(vlan->vid);
 		tt_vlan->crc = htonl(vlan->tt.crc);
 		tt_vlan->reserved = 0;
 
 		tt_vlan++;
+		num_vlan++;
 	}
 
+	/* recalculate in case number of VLANs reduced */
+	change_offset = sizeof(**tt_data);
+	change_offset += num_vlan * sizeof(*tt_vlan);
+	tvlv_len = *tt_len + change_offset;
+
+	(*tt_data)->num_vlan = htons(num_vlan);
+
 	tt_change_ptr = (u8 *)*tt_data + change_offset;
 	*tt_change = (struct batadv_tvlv_tt_change *)tt_change_ptr;
 
Signature · 1 line
2.47.3
maintainer Applied
#2 lore raw

Re: [PATCH 6.12.y] batman-adv: tt: avoid empty VLAN responses

Queued for 6.6.y, 6.12.y, 6.1.y, 5.15.y, and 5.10.y, thanks.

Signature · 2 lines
Thanks,
Sasha