diff options
| author | Manjunatha Venkatesh <manjunatha.venkatesh@nxp.com> | 2025-03-26 18:00:46 +0530 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2025-03-31 11:44:00 +0200 |
| commit | bd496a44f041da9ef3afe14d1d6193d460424e91 (patch) | |
| tree | cf8fb0b5e587f854d69dc99f104750e8d51316fc | |
| parent | 465e5486aa5e1cdedc910bc3487ca92c5e6d51c4 (diff) | |
i3c: Add NULL pointer check in i3c_master_queue_ibi()
The I3C master driver may receive an IBI from a target device that has not
been probed yet. In such cases, the master calls `i3c_master_queue_ibi()`
to queue an IBI work task, leading to "Unable to handle kernel read from
unreadable memory" and resulting in a kernel panic.
Typical IBI handling flow:
1. The I3C master scans target devices and probes their respective drivers.
2. The target device driver calls `i3c_device_request_ibi()` to enable IBI
and assigns `dev->ibi = ibi`.
3. The I3C master receives an IBI from the target device and calls
`i3c_master_queue_ibi()` to queue the target device driver’s IBI
handler task.
However, since target device events are asynchronous to the I3C probe
sequence, step 3 may occur before step 2, causing `dev->ibi` to be `NULL`,
leading to a kernel panic.
Add a NULL pointer check in `i3c_master_queue_ibi()` to prevent accessing
an uninitialized `dev->ibi`, ensuring stability.
Fixes: 3a379bbcea0af ("i3c: Add core I3C infrastructure")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/Z9gjGYudiYyl3bSe@lizhi-Precision-Tower-5810/
Signed-off-by: Manjunatha Venkatesh <manjunatha.venkatesh@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250326123047.2797946-1-manjunatha.venkatesh@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
| -rw-r--r-- | drivers/i3c/master.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index fd26c4bb8b34..fd81871609d9 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -2555,6 +2555,9 @@ static void i3c_master_unregister_i3c_devs(struct i3c_master_controller *master) */ void i3c_master_queue_ibi(struct i3c_dev_desc *dev, struct i3c_ibi_slot *slot) { + if (!dev->ibi || !slot) + return; + atomic_inc(&dev->ibi->pending_ibis); queue_work(dev->ibi->wq, &slot->work); } |