High · published October 21, 2024
In the Linux kernel, the following vulnerability has been resolved:
block, bfq: fix uaf for accessing waker_bfqq after splitting
After commit 42c306ed7233 ("block, bfq: don't break merge chain in
bfq_split_bfqq()"), if the current procress is the last holder of bfqq,
the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and
then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq
may in the merge chain of bfqq, hence just recored waker_bfqq is still
not safe.
Fix the problem by adding a helper bfq_waker_bfqq() to check if
bfqq->waker_bfqq is in the merge chain, and current procress is the only
holder.
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 5.10.227, < 5.15.168 | 5.15.168 |
| linux/linux_kernel | ≥ 5.16, < 6.1.113 | 6.1.113 |
| linux/linux_kernel | ≥ 6.2, < 6.6.54 | 6.6.54 |
| linux/linux_kernel | ≥ 6.7, < 6.10.13 | 6.10.13 |
| linux/linux_kernel | ≥ 6.11, < 6.11.2 | 6.11.2 |