From: Greg KH <gregkh@linuxfoundation.org>
To: Alexander Wetzel <lifangxu22@gmail.com>
Cc: stable@vger.kernel.org, johannes@sipsolutions.net,
linux-wireless@vger.kernel.org, lifangxu@kylinos.cn,
Alexander Wetzel <Alexander@wetzel-home.de>,
Johannes Berg <johannes.berg@intel.com>
Subject: Re: [PATCH 5.4.y] wifi: cfg80211: Add missing lock in cfg80211_check_and_end_cac()
Date: Wed, 27 Aug 2025 17:11:14 +0200 [thread overview]
Message-ID: <2025082749-strength-baffling-eb44@gregkh> (raw)
In-Reply-To: <20250827144502.1401-1-Alexander@wetzel-home.de>
On Wed, Aug 27, 2025 at 10:45:02PM +0800, Alexander Wetzel wrote:
> [ Upstream commit 2c5dee15239f3f3e31aa5c8808f18996c039e2c1 ]
>
> Callers of wdev_chandef() must hold the wiphy mutex.
>
> But the worker cfg80211_propagate_cac_done_wk() never takes the lock.
> Which triggers the warning below with the mesh_peer_connected_dfs
> test from hostapd and not (yet) released mac80211 code changes:
>
> WARNING: CPU: 0 PID: 495 at net/wireless/chan.c:1552 wdev_chandef+0x60/0x165
> Modules linked in:
> CPU: 0 UID: 0 PID: 495 Comm: kworker/u4:2 Not tainted 6.14.0-rc5-wt-g03960e6f9d47 #33 13c287eeabfe1efea01c0bcc863723ab082e17cf
> Workqueue: cfg80211 cfg80211_propagate_cac_done_wk
> Stack:
> 00000000 00000001 ffffff00 6093267c
> 00000000 6002ec30 6d577c50 60037608
> 00000000 67e8d108 6063717b 00000000
> Call Trace:
> [<6002ec30>] ? _printk+0x0/0x98
> [<6003c2b3>] show_stack+0x10e/0x11a
> [<6002ec30>] ? _printk+0x0/0x98
> [<60037608>] dump_stack_lvl+0x71/0xb8
> [<6063717b>] ? wdev_chandef+0x60/0x165
> [<6003766d>] dump_stack+0x1e/0x20
> [<6005d1b7>] __warn+0x101/0x20f
> [<6005d3a8>] warn_slowpath_fmt+0xe3/0x15d
> [<600b0c5c>] ? mark_lock.part.0+0x0/0x4ec
> [<60751191>] ? __this_cpu_preempt_check+0x0/0x16
> [<600b11a2>] ? mark_held_locks+0x5a/0x6e
> [<6005d2c5>] ? warn_slowpath_fmt+0x0/0x15d
> [<60052e53>] ? unblock_signals+0x3a/0xe7
> [<60052f2d>] ? um_set_signals+0x2d/0x43
> [<60751191>] ? __this_cpu_preempt_check+0x0/0x16
> [<607508b2>] ? lock_is_held_type+0x207/0x21f
> [<6063717b>] wdev_chandef+0x60/0x165
> [<605f89b4>] regulatory_propagate_dfs_state+0x247/0x43f
> [<60052f00>] ? um_set_signals+0x0/0x43
> [<605e6bfd>] cfg80211_propagate_cac_done_wk+0x3a/0x4a
> [<6007e460>] process_scheduled_works+0x3bc/0x60e
> [<6007d0ec>] ? move_linked_works+0x4d/0x81
> [<6007d120>] ? assign_work+0x0/0xaa
> [<6007f81f>] worker_thread+0x220/0x2dc
> [<600786ef>] ? set_pf_worker+0x0/0x57
> [<60087c96>] ? to_kthread+0x0/0x43
> [<6008ab3c>] kthread+0x2d3/0x2e2
> [<6007f5ff>] ? worker_thread+0x0/0x2dc
> [<6006c05b>] ? calculate_sigpending+0x0/0x56
> [<6003b37d>] new_thread_handler+0x4a/0x64
> irq event stamp: 614611
> hardirqs last enabled at (614621): [<00000000600bc96b>] __up_console_sem+0x82/0xaf
> hardirqs last disabled at (614630): [<00000000600bc92c>] __up_console_sem+0x43/0xaf
> softirqs last enabled at (614268): [<00000000606c55c6>] __ieee80211_wake_queue+0x933/0x985
> softirqs last disabled at (614266): [<00000000606c52d6>] __ieee80211_wake_queue+0x643/0x985
>
> Fixes: 26ec17a1dc5e ("cfg80211: Fix radar event during another phy CAC")
> Signed-off-by: Alexander Wetzel <Alexander@wetzel-home.de>
> Link: https://patch.msgid.link/20250717162547.94582-1-Alexander@wetzel-home.de
> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
>
> Conflicts:
> net/wireless/reg.c
This isn't needed.
> Signed-off-by: lifangxu <lifangxu@kylinos.cn>
This has to match the From: line like any other patch you send :(
Can you please fix up and resend?
thanks,
greg k-h
next prev parent reply other threads:[~2025-08-27 15:11 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-27 14:45 [PATCH 5.4.y] wifi: cfg80211: Add missing lock in cfg80211_check_and_end_cac() Alexander Wetzel
2025-08-27 15:11 ` Greg KH [this message]
2025-08-28 8:16 ` Withdraw [PATCH 5.4.y] wifi: cfg80211: Add missing lock in cfg80211_check_and_end_cac lifangxu
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