It was originally meant to replace the dev_hold with netdev_hold. But this
was missed in batadv_hardif_enable_interface(). As result, there was an
imbalance and a hang when trying to remove the mesh-interface with
(previously) active hard-interfaces:
unregister_netdevice: waiting for batadv0 to become free. Usage count = 3
Fixes: 00b35530811f ("batman-adv: adopt netdev_hold() / netdev_put()")
Suggested-by: Eric Dumazet <[email protected]>
Reported-by: [email protected]
Reported-by: [email protected]
Reported-by: [email protected]
Reported-by: [email protected]
Reported-by: [email protected]
Signed-off-by: Sven Eckelmann <[email protected]>
---
This patch is skipping Simon's normal PR submission to get this problem
fixed faster in Linus' tree. This currently creates quite a lot of wrong
bisect results for syzkaller and it would be better to have this fixed
sooner than later.
---
Changes in v5:
- added Suggested-by: Eric Dumazet <[email protected]>
- added Reported-by: of various syzkaller reports which were affected (during
bisecting) by this problem
- Link to v4:
https://lore.kernel.org/r/[email protected]
Changes in v4:
- resubmission after 24h cooldown time
- added kernel message during hang to commit message
- Link to v3:
https://lore.kernel.org/r/[email protected]
Changes in v3:
- fix submitter address
- Link to v2:
https://lore.kernel.org/r/[email protected]
Changes in v2:
- add missing commit message
- Link to v1:
https://lore.kernel.org/r/[email protected]
---
net/batman-adv/hard-interface.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index
f145f96626531053bbf8f58a31f28f625a9d80f9..7cd4bdcee43935b9e5fb7d1696430909b7af67b4
100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -725,7 +725,6 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface
*hard_iface,
kref_get(&hard_iface->refcount);
- dev_hold(mesh_iface);
netdev_hold(mesh_iface, &hard_iface->meshif_dev_tracker, GFP_ATOMIC);
hard_iface->mesh_iface = mesh_iface;
bat_priv = netdev_priv(hard_iface->mesh_iface);
---
base-commit: 61f96e684edd28ca40555ec49ea1555df31ba619
change-id: 20250410-double_hold_fix-8f0a87f72ad9
Best regards,
--
Sven Eckelmann <[email protected]>
