diff options
| author | Adrian Hunter <adrian.hunter@intel.com> | 2026-07-23 10:57:47 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-09-07 17:22:57 +0200 |
| commit | 94fb9786d67a8f8b899e77381620f86bad94fdf7 (patch) | |
| tree | 5934cc09516d1a11fe47e9815140c0937eeb004a | |
| parent | a15a1b95de980362c14f32f519b293b0d12ce86f (diff) | |
| download | linux-94fb9786d67a8f8b899e77381620f86bad94fdf7.tar.gz linux-94fb9786d67a8f8b899e77381620f86bad94fdf7.zip | |
i3c: master: Fix info leak and UAF in device unregister path
commit d2c743efd2d1ee64e94324664808f623dd865872 upstream.
i3c_master_unregister_i3c_devs() clears i3cdev->dev->desc before
calling device_unregister(). During device_unregister(),
device_del() emits a KOBJ_REMOVE uevent and unbinds the driver while
the device descriptor is still expected to be valid. As a result,
i3c_device_uevent() and a racing modalias_show() can observe a NULL
desc and fall back to an uninitialized stack struct i3c_device_info,
leaking kernel stack contents in the generated modalias. Driver
.remove() callbacks may also encounter an unexpected NULL desc during
unbind.
Keep desc valid until device_unregister() has completed. Since
device_unregister() drops the device reference and may free the device,
take an extra reference with get_device() before unregistering. Clear
desc afterwards and release the extra reference with put_device().
This preserves the release-time invariant that desc must be NULL while
avoiding both the information leak and a potential use-after-free from
writing desc after the device has been released.
Reported-by: sashiko-bot@kernel.org
Link: https://lore.kernel.org/linux-i3c/20260702190003.8BF741F000E9@smtp.kernel.org/
Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure")
Cc: stable@vger.kernel.org
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260723075747.34049-1-adrian.hunter@intel.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 | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index 588395e7a770..41452a27262d 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -2808,11 +2808,12 @@ static void i3c_master_unregister_i3c_devs(struct i3c_master_controller *master) if (!i3cdev->dev) continue; - i3cdev->dev->desc = NULL; - if (device_is_registered(&i3cdev->dev->dev)) + if (device_is_registered(&i3cdev->dev->dev)) { + get_device(&i3cdev->dev->dev); device_unregister(&i3cdev->dev->dev); - else - put_device(&i3cdev->dev->dev); + } + i3cdev->dev->desc = NULL; + put_device(&i3cdev->dev->dev); i3cdev->dev = NULL; } } |