This is a note to let you know that I've just added the patch titled
media: dm1105: Fix use after free bug in dm1105_remove due to race condition
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
media-dm1105-fix-use-after-free-bug-in-dm1105_remove.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 32f61a4583678681db6ffdb0ee6ff02f8c0f9040
Author: Zheng Wang <zyytlz.wz@xxxxxxx>
Date: Sat Mar 18 16:15:06 2023 +0800
media: dm1105: Fix use after free bug in dm1105_remove due to race condition
[ Upstream commit 5abda7a16698d4d1f47af1168d8fa2c640116b4a ]
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@xxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/media/pci/dm1105/dm1105.c b/drivers/media/pci/dm1105/dm1105.c
index 1ddb0576fb7b1..dc3fc69e44806 100644
--- a/drivers/media/pci/dm1105/dm1105.c
+++ b/drivers/media/pci/dm1105/dm1105.c
@@ -1188,6 +1188,7 @@ 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);
