In the Linux kernel, the following vulnerability has been resolved:
page_pool: avoid infinite loop to schedule delayed worker
We noticed the kworker in page_pool_release_retry() was waken up repeatedly and infinitely in production because of the buggy driver causing the inflight less than 0 and warning us in page_pool_inflight()[1].
Since the inflight value goes negative, it means we should not expect the whole page_pool to get back to work normally.
This patch mitigates the adverse effect by not rescheduling the kworker when detecting the inflight negative in page_pool_release_retry().
[1] [Mon Feb 10 20:36:11 2025] ------------[ cut here ]------------ [Mon Feb 10 20:36:11 2025] Negative(-51446) inflight packet-pages ... [Mon Feb 10 20:36:11 2025] Call Trace: [Mon Feb 10 20:36:11 2025] page_pool_release_retry+0x23/0x70 [Mon Feb 10 20:36:11 2025] process_one_work+0x1b1/0x370 [Mon Feb 10 20:36:11 2025] worker_thread+0x37/0x3a0 [Mon Feb 10 20:36:11 2025] kthread+0x11a/0x140 [Mon Feb 10 20:36:11 2025] ? process_one_work+0x370/0x370 [Mon Feb 10 20:36:11 2025] ? __kthread_cancel_work+0x40/0x40 [Mon Feb 10 20:36:11 2025] ret_from_fork+0x35/0x40 [Mon Feb 10 20:36:11 2025] ---[ end trace ebffe800f33e7e34 ]--- Note: before this patch, the above calltrace would flood the dmesg due to repeated reschedule of release_dw kworker.
| Software | From | Fixed in |
|---|---|---|
| linux / linux_kernel | 5.3.18 | 5.4 |
| linux / linux_kernel | 5.4.5 | 5.4.293 |
| linux / linux_kernel | 5.5 | 5.10.237 |
| linux / linux_kernel | 5.11 | 5.15.181 |
| linux / linux_kernel | 5.16 | 6.1.135 |
| linux / linux_kernel | 6.2 | 6.6.88 |
| linux / linux_kernel | 6.7 | 6.12.24 |
| linux / linux_kernel | 6.13 | 6.13.12 |
| linux / linux_kernel | 6.14 | 6.14.3 |
| debian / debian_linux | 11.0 | 11.0.x |