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Subject[PATCH] media: dm1105: Fix use after free bug in dm1105_remove due to race condition
Date
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>
---
drivers/media/pci/dm1105/dm1105.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/media/pci/dm1105/dm1105.c b/drivers/media/pci/dm1105/dm1105.c
index 4ac645a56c14..9e9c7c071acc 100644
--- a/drivers/media/pci/dm1105/dm1105.c
+++ b/drivers/media/pci/dm1105/dm1105.c
@@ -1176,6 +1176,7 @@ static void dm1105_remove(struct pci_dev *pdev)
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);
--
2.25.1
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