| Message ID | 20250410-double_hold_fix-v4-1-2f606fe8c204@narfation.org (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net,v4] batman-adv: Fix double-hold of meshif when getting enabled | expand |
On Thu, Apr 10, 2025 at 08:58:51PM +0200, Sven Eckelmann wrote: > 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()") > Signed-off-by: Sven Eckelmann <sven@narfation.org> > --- > 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 v4: > - added Suggested-by: Eric Dumazet <edumazet@google.com> > - added Reported-by: of various syzkaller reports which were affected (during > bisecting) by this problem FWIIW, I don't see those tags at the bottom of the commit message. > - resubmission after 24h cooldown time > - added kernel message during hang to commit message > - Link to v3: https://lore.kernel.org/r/20250409073524.557189-1-sven@narfation.org > Changes in v3: > - fix submitter address > - Link to v2: https://lore.kernel.org/r/20250409073304.556841-1-sw@simonwunderlich.de > Changes in v2: > - add missing commit message > - Link to v1: https://lore.kernel.org/r/20250409073000.556263-1-sven@narfation.org ...
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);
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()") Signed-off-by: Sven Eckelmann <sven@narfation.org> --- 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 v4: - added Suggested-by: Eric Dumazet <edumazet@google.com> - added Reported-by: of various syzkaller reports which were affected (during bisecting) by this problem - resubmission after 24h cooldown time - added kernel message during hang to commit message - Link to v3: https://lore.kernel.org/r/20250409073524.557189-1-sven@narfation.org Changes in v3: - fix submitter address - Link to v2: https://lore.kernel.org/r/20250409073304.556841-1-sw@simonwunderlich.de Changes in v2: - add missing commit message - Link to v1: https://lore.kernel.org/r/20250409073000.556263-1-sven@narfation.org --- net/batman-adv/hard-interface.c | 1 - 1 file changed, 1 deletion(-) --- base-commit: 61f96e684edd28ca40555ec49ea1555df31ba619 change-id: 20250410-double_hold_fix-8f0a87f72ad9 Best regards,