[PATCH 5.10 164/491] wifi: cfg80211: cancel rfkill_block work in wiphy_unregister()

Greg Kroah-Hartman
2026-04-13T16:49:43Z

From: Daniil Dulov <d.dulov@aladdin.ru>

[ Upstream commit 767d23ade706d5fa51c36168e92a9c5533c351a1 ]

There is a use-after-free error in cfg80211_shutdown_all_interfaces found
by syzkaller:

BUG: KASAN: use-after-free in cfg80211_shutdown_all_interfaces+0x213/0x220
Read of size 8 at addr ffff888112a78d98 by task kworker/0:5/5326
CPU: 0 UID: 0 PID: 5326 Comm: kworker/0:5 Not tainted 6.19.0-rc2 #2 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Workqueue: events cfg80211_rfkill_block_work
Call Trace:
<TASK>
dump_stack_lvl+0x116/0x1f0
print_report+0xcd/0x630
kasan_report+0xe0/0x110
cfg80211_shutdown_all_interfaces+0x213/0x220
cfg80211_rfkill_block_work+0x1e/0x30
process_one_work+0x9cf/0x1b70
worker_thread+0x6c8/0xf10
kthread+0x3c5/0x780
ret_from_fork+0x56d/0x700
ret_from_fork_asm+0x1a/0x30
</TASK>

The problem arises due to the rfkill_block work is not cancelled when wiphy
is being unregistered. In order to fix the issue cancel the corresponding
work in wiphy_unregister().

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 1f87f7d3a3b4 ("cfg80211: add rfkill support")
Cc: stable@vger.kernel.org
Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru>
Link: https://patch.msgid.link/20260211082024.1967588-1-d.dulov@aladdin.ru
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
[ Context ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/wireless/core.c | 1 +
1 file changed, 1 insertion(+)

--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -1046,6 +1046,7 @@ void wiphy_unregister(struct wiphy *wiph
rtnl_unlock();

flush_work(&rdev->scan_done_wk);
+ cancel_work_sync(&rdev->rfkill_block);
cancel_work_sync(&rdev->conn_work);
flush_work(&rdev->event_work);
cancel_delayed_work_sync(&rdev->dfs_update_channels_wk);