High · published March 11, 2024
In the Linux kernel, the following vulnerability has been resolved:
media: mtk-jpeg: Fix use after free bug due to error path handling in mtk_jpeg_dec_device_run
In mtk_jpeg_probe, &jpeg->job_timeout_work is bound with
mtk_jpeg_job_timeout_work.
In mtk_jpeg_dec_device_run, if error happens in
mtk_jpeg_set_dec_dst, it will finally start the worker while
mark the job as finished by invoking v4l2_m2m_job_finish.
There are two methods to trigger the bug. If we remove the
module, it which will call mtk_jpeg_remove to make cleanup.
The possible sequence is as follows, which will cause a
use-after-free bug.
CPU0 CPU1
mtk_jpeg_dec_... |
start worker |
|mtk_jpeg_job_timeout_work
mtk_jpeg_remove |
v4l2_m2m_release |
kfree(m2m_dev); |
|
| v4l2_m2m_get_curr_priv
| m2m_dev->curr_ctx //use
If we close the file descriptor, which will call mtk_jpeg_release,
it will have a similar sequence.
Fix this bug by starting timeout worker only if started jpegdec worker
successfully. Then v4l2_m2m_job_finish will only be called in
either mtk_jpeg_job_timeout_work or mtk_jpeg_dec_device_run.
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 4.12, < 5.10.210 | 5.10.210 |
| linux/linux_kernel | ≥ 5.11, < 5.15.149 | 5.15.149 |
| linux/linux_kernel | ≥ 5.16, < 6.1.76 | 6.1.76 |
| linux/linux_kernel | ≥ 6.2, < 6.6.15 | 6.6.15 |
| linux/linux_kernel | ≥ 6.7, < 6.7.3 | 6.7.3 |