6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Duoming Zhou <redacted>
[ Upstream commit 1146d0946b5358fad24812bd39d68f31cd40cc34 ]
When the mt7915 pci chip is detaching, the mt7915_crash_data is
released in mt7915_coredump_unregister(). However, the work item
dump_work may still be running or pending, leading to UAF bugs
when the already freed crash_data is dereferenced again in
mt7915_mac_dump_work().
The race condition can occur as follows:
CPU 0 (removal path) | CPU 1 (workqueue)
mt7915_pci_remove() | mt7915_sys_recovery_set()
mt7915_unregister_device() | mt7915_reset()
mt7915_coredump_unregister() | queue_work()
vfree(dev->coredump.crash_data) | mt7915_mac_dump_work()
| crash_data-> // UAF
Fix this by ensuring dump_work is properly canceled before
the crash_data is deallocated. Add cancel_work_sync() in
mt7915_unregister_device() to synchronize with any pending
or executing dump work.
Fixes: 4dbcb9125cc3 ("wifi: mt76: mt7915: enable coredump support")
Signed-off-by: Duoming Zhou <redacted>
Link: https://patch.msgid.link/20260130145759.84272-1-duoming@zju.edu.cn (local)
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/mediatek/mt76/mt7915/init.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/init.c b/drivers/net/wireless/mediatek/mt76/mt7915/init.c
index 38027699cad07..7d1e2aa732897 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/init.c
@@ -1150,6 +1150,7 @@ int mt7915_register_device(struct mt7915_dev *dev)
void mt7915_unregister_device(struct mt7915_dev *dev)
{
+ cancel_work_sync(&dev->dump_work);
mt7915_unregister_ext_phy(dev);
mt7915_coredump_unregister(dev);
mt7915_unregister_thermal(&dev->phy);--
2.53.0