diff options
| author | Manjunatha Venkatesh <manjunatha.venkatesh@nxp.com> | 2025-03-26 18:00:46 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-05-02 07:39:15 +0200 |
| commit | 1b54faa5f47fa7c642179744aeff03f0810dc62e (patch) | |
| tree | d0b422b76e0bda6416f9a337b199a3b2a9cd2346 | |
| parent | b96bd2c3db26ad0daec5b78c85c098b53900e2e1 (diff) | |
i3c: Add NULL pointer check in i3c_master_queue_ibi()
commit bd496a44f041da9ef3afe14d1d6193d460424e91 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 3f581a1cf8e6..8604c9e7b6ac 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -2198,6 +2198,9 @@ 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->common.master->wq, &slot->work); } |