From: Zheng Wang <zyytlz.wz@163.com>
Date: Sat, 18 Mar 2023 16:15:06 +0800
Subject: media: dm1105: Fix use after free bug in dm1105_remove due to race
condition
Patch-mainline: v6.4-rc1
Git-commit: 5abda7a16698d4d1f47af1168d8fa2c640116b4a
References: bsc#1212501 CVE-2023-35824
In dm1105_probe, it called dm1105_ir_init and bound
&dm1105->ir.work with dm1105_emit_key.
When it handles IRQ request with dm1105_irq,
it may call schedule_work to start the work.
When we call dm1105_remove to remove the driver, there
may be a sequence as follows:
Fix it by finishing the work before cleanup in dm1105_remove
CPU0 CPU1
|dm1105_emit_key
dm1105_remove |
dm1105_ir_exit |
rc_unregister_device |
rc_free_device |
rc_dev_release |
kfree(dev); |
|
| rc_keydown
| //use
Fixes: 34d2f9bf189c ("V4L/DVB: dm1105: use dm1105_dev & dev instead of dm1105dvb")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
drivers/media/pci/dm1105/dm1105.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/media/pci/dm1105/dm1105.c
+++ b/drivers/media/pci/dm1105/dm1105.c
@@ -1186,6 +1186,7 @@ static void dm1105_remove(struct pci_dev
struct dvb_demux *dvbdemux = &dev->demux;
struct dmx_demux *dmx = &dvbdemux->dmx;
+ cancel_work_sync(&dev->ir.work);
dm1105_ir_exit(dev);
dmx->close(dmx);
dvb_net_release(&dev->dvbnet);