* [PATCH 5.10/5.15] wifi: mac80211: mesh: release the channel if start fails
@ 2026-10-08 11:51 Alexander Martyniuk
2026-10-08 19:19 ` Fedor Pchelkin
0 siblings, 1 reply; 3+ messages in thread
From: Alexander Martyniuk @ 2026-10-08 11:51 UTC (permalink / raw)
To: stable, Greg Kroah-Hartman
Cc: Alexander Martyniuk, Johannes Berg, David S. Miller,
Jakub Kicinski, Thomas Pedersen, linux-wireless, netdev,
linux-kernel, lvc-project, syzbot+63a84ea9c0f57d6133fa,
Johannes Berg
From: Johannes Berg <johannes.berg@intel.com>
commit ae97fff6495a8764bc0ef281cfe5444f701e527f upstream.
ieee80211_join_mesh() acquires a channel context and then calls
ieee80211_start_mesh(), which can fail. In that case, the chanctx
isn't released then interface removal will attempt to unassign it
after it's removed from the driver, hitting:
wlan0: Failed check-sdata-in-driver check, flags: 0x0
WARNING: net/mac80211/driver-ops.c:366 at drv_unassign_vif_chanctx
ieee80211_assign_link_chanctx
__ieee80211_link_release_channel
ieee80211_link_release_channel
ieee80211_teardown_sdata
unregister_netdevice_many_notify
_cfg80211_unregister_wdev
ieee80211_remove_interfaces
ieee80211_unregister_hw
mac80211_hwsim_del_radio
hwsim_exit_net
Correctly release the channel on start failures.
Assisted-by: LLM
Reported-by: syzbot+63a84ea9c0f57d6133fa@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=63a84ea9c0f57d6133fa
Fixes: 2b5e19677592 ("mac80211: cache mesh beacon")
Link: https://patch.msgid.link/20260908122838.201719-21-johannes@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Alexander Martyniuk <alexevgmart@gmail.com>
---
Backport fix for CVE-2026-98326
net/mac80211/cfg.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index afb1ad3e6ea1..bae9588ea913 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2276,7 +2276,11 @@ static int ieee80211_join_mesh(struct wiphy *wiphy, struct net_device *dev,
if (err)
return err;
- return ieee80211_start_mesh(sdata);
+ err = ieee80211_start_mesh(sdata);
+ if (err)
+ ieee80211_vif_release_channel(sdata);
+
+ return err;
}
static int ieee80211_leave_mesh(struct wiphy *wiphy, struct net_device *dev)
--
2.43.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 5.10/5.15] wifi: mac80211: mesh: release the channel if start fails
2026-10-08 11:51 [PATCH 5.10/5.15] wifi: mac80211: mesh: release the channel if start fails Alexander Martyniuk
@ 2026-10-08 19:19 ` Fedor Pchelkin
2026-10-09 12:39 ` [PATCH 5.10/5.15 v2] " Alexander Martyniuk
0 siblings, 1 reply; 3+ messages in thread
From: Fedor Pchelkin @ 2026-10-08 19:19 UTC (permalink / raw)
To: Alexander Martyniuk
Cc: stable, Greg Kroah-Hartman, lvc-project, Johannes Berg,
Thomas Pedersen, linux-wireless, linux-kernel,
syzbot+63a84ea9c0f57d6133fa, netdev, Jakub Kicinski,
Johannes Berg, David S. Miller
On Thu, 08. Oct 14:51, Alexander Martyniuk wrote:
> From: Johannes Berg <johannes.berg@intel.com>
>
> commit ae97fff6495a8764bc0ef281cfe5444f701e527f upstream.
>
> ieee80211_join_mesh() acquires a channel context and then calls
> ieee80211_start_mesh(), which can fail. In that case, the chanctx
> isn't released then interface removal will attempt to unassign it
> after it's removed from the driver, hitting:
>
> wlan0: Failed check-sdata-in-driver check, flags: 0x0
> WARNING: net/mac80211/driver-ops.c:366 at drv_unassign_vif_chanctx
> ieee80211_assign_link_chanctx
> __ieee80211_link_release_channel
> ieee80211_link_release_channel
> ieee80211_teardown_sdata
> unregister_netdevice_many_notify
> _cfg80211_unregister_wdev
> ieee80211_remove_interfaces
> ieee80211_unregister_hw
> mac80211_hwsim_del_radio
> hwsim_exit_net
>
> Correctly release the channel on start failures.
>
> Assisted-by: LLM
> Reported-by: syzbot+63a84ea9c0f57d6133fa@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=63a84ea9c0f57d6133fa
> Fixes: 2b5e19677592 ("mac80211: cache mesh beacon")
> Link: https://patch.msgid.link/20260908122838.201719-21-johannes@sipsolutions.net
> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
> Signed-off-by: Alexander Martyniuk <alexevgmart@gmail.com>
> ---
> Backport fix for CVE-2026-98326
> net/mac80211/cfg.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
> index afb1ad3e6ea1..bae9588ea913 100644
> --- a/net/mac80211/cfg.c
> +++ b/net/mac80211/cfg.c
> @@ -2276,7 +2276,11 @@ static int ieee80211_join_mesh(struct wiphy *wiphy, struct net_device *dev,
> if (err)
> return err;
>
> - return ieee80211_start_mesh(sdata);
> + err = ieee80211_start_mesh(sdata);
> + if (err)
> + ieee80211_vif_release_channel(sdata);
In 5.10/5.15 ieee80211_vif_release_channel() requires &sdata->local->mtx
to be held, it has the corresponding lockdep assertion.
Besides, the backport uses a different release-function, relevant for old
kernels. I understand that's an adaptation but FWIW it's generally
recommended to write a brief backporter's comment above one's SoB line if
any non-trivial adaptation is done.
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH 5.10/5.15 v2] wifi: mac80211: mesh: release the channel if start fails
2026-10-08 19:19 ` Fedor Pchelkin
@ 2026-10-09 12:39 ` Alexander Martyniuk
0 siblings, 0 replies; 3+ messages in thread
From: Alexander Martyniuk @ 2026-10-09 12:39 UTC (permalink / raw)
To: pchelkin, stable, Greg Kroah-Hartman
Cc: alexevgmart, davem, johannes.berg, johannes, kuba, linux-kernel,
linux-wireless, lvc-project, netdev, syzbot+63a84ea9c0f57d6133fa,
thomas
From: Johannes Berg <johannes.berg@intel.com>
commit ae97fff6495a8764bc0ef281cfe5444f701e527f upstream.
ieee80211_join_mesh() acquires a channel context and then calls
ieee80211_start_mesh(), which can fail. In that case, the chanctx
isn't released then interface removal will attempt to unassign it
after it's removed from the driver, hitting:
wlan0: Failed check-sdata-in-driver check, flags: 0x0
WARNING: net/mac80211/driver-ops.c:366 at drv_unassign_vif_chanctx
ieee80211_assign_link_chanctx
__ieee80211_link_release_channel
ieee80211_link_release_channel
ieee80211_teardown_sdata
unregister_netdevice_many_notify
_cfg80211_unregister_wdev
ieee80211_remove_interfaces
ieee80211_unregister_hw
mac80211_hwsim_del_radio
hwsim_exit_net
Correctly release the channel on start failures.
Assisted-by: LLM
Reported-by: syzbot+63a84ea9c0f57d6133fa@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=63a84ea9c0f57d6133fa
Fixes: 2b5e19677592 ("mac80211: cache mesh beacon")
Link: https://patch.msgid.link/20260908122838.201719-21-johannes@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
[Alexander: No such function ieee80211_link_release_channel(), so
ieee80211_vif_release_channel() is used]
Signed-off-by: Alexander Martyniuk <alexevgmart@gmail.com>
---
Backport fix for CVE-2026-98326
net/mac80211/cfg.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 29bcb5f6013a..d5865f4083cf 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2311,7 +2311,14 @@ static int ieee80211_join_mesh(struct wiphy *wiphy, struct net_device *dev,
if (err)
return err;
- return ieee80211_start_mesh(sdata);
+ err = ieee80211_start_mesh(sdata);
+ if (err) {
+ mutex_lock(&sdata->local->mtx);
+ ieee80211_vif_release_channel(sdata);
+ mutex_unlock(&sdata->local->mtx);
+ }
+
+ return err;
}
static int ieee80211_leave_mesh(struct wiphy *wiphy, struct net_device *dev)
--
2.43.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2026-10-08 11:51 [PATCH 5.10/5.15] wifi: mac80211: mesh: release the channel if start fails Alexander Martyniuk
2026-10-08 19:19 ` Fedor Pchelkin
2026-10-09 12:39 ` [PATCH 5.10/5.15 v2] " Alexander Martyniuk
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