diff options
| author | Sean Young <sean@mess.org> | 2025-12-20 10:33:26 +0000 |
|---|---|---|
| committer | Hans Verkuil <hverkuil+cisco@kernel.org> | 2026-03-17 14:43:56 +0100 |
| commit | dccc0c3ddf8f16071736f98a7d6dd46a2d43e037 (patch) | |
| tree | 9a0fd3d7a95072afd56a5e56c5e580693700c7da /include | |
| parent | a5dcbff7d50a89bf0376e7f2fb1ba3163a6dac0a (diff) | |
media: rc: fix race between unregister and urb/irq callbacks
Some rc device drivers have a race condition between rc_unregister_device()
and irq or urb callbacks. This is because rc_unregister_device() does two
things, it marks the device as unregistered so no new commands can be
issued and then it calls rc_free_device(). This means the driver has no
chance to cancel any pending urb callbacks or interrupts after the device
has been marked as unregistered. Those callbacks may access struct rc_dev
or its members (e.g. struct ir_raw_event_ctrl), which have been freed by
rc_free_device().
This change removes the implicit call to rc_free_device() from
rc_unregister_device(). This means that device drivers can call
rc_unregister_device() in their remove or disconnect function, then cancel
all the urbs and interrupts before explicitly calling rc_free_device().
Note this is an alternative fix for an issue found by Haotian Zhang, see
the Closes: tags.
Reported-by: Haotian Zhang <vulab@iscas.ac.cn>
Closes: https://lore.kernel.org/linux-media/20251114101432.2566-1-vulab@iscas.ac.cn/
Closes: https://lore.kernel.org/linux-media/20251114101418.2548-1-vulab@iscas.ac.cn/
Closes: https://lore.kernel.org/linux-media/20251114101346.2530-1-vulab@iscas.ac.cn/
Closes: https://lore.kernel.org/linux-media/20251114090605.2413-1-vulab@iscas.ac.cn/
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/media/rc-core.h | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/include/media/rc-core.h b/include/media/rc-core.h index 35c7a0546f02..7c964b5ad792 100644 --- a/include/media/rc-core.h +++ b/include/media/rc-core.h @@ -81,7 +81,6 @@ struct lirc_fh { /** * struct rc_dev - represents a remote control device * @dev: driver model's view of this device - * @managed_alloc: devm_rc_allocate_device was used to create rc_dev * @registered: set to true by rc_register_device(), false by * rc_unregister_device * @idle: used to keep track of RX state @@ -156,7 +155,6 @@ struct lirc_fh { */ struct rc_dev { struct device dev; - bool managed_alloc; bool registered; bool idle; bool encode_wakeup; |