In the Linux kernel, the following vulnerability has been resolved: sch_htb: fix refcount leak in htb_parent_to_leaf_offload The commit ae81feb7338c (“sch_htb: fix null pointer dereference on a null new_q”) fixes a NULL pointer dereference bug, but it is not correct. Because htb_graft_helper properly handles the case when new_q is NULL, and after the previous patch by skipping this call which creates an inconsistency : dev_queue->qdisc will still point to the old qdisc, but cl->parent->leaf.q will point to the new one (which will be noop_qdisc, because new_q was NULL). The code is based on an assumption that these two pointers are the same, so it can lead to refcount leaks. The correct fix is to add a NULL pointer check to protect qdisc_refcount_inc inside htb_parent_to_leaf_offload.
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
Debian | 12 | all | linux | < 6.1.94-1 | linux_6.1.94-1_all.deb |
Debian | 11 | all | linux | < 5.10.218-1 | linux_5.10.218-1_all.deb |
Debian | 999 | all | linux | < 6.9.7-1 | linux_6.9.7-1_all.deb |
Debian | 13 | all | linux | < 6.8.12-1 | linux_6.8.12-1_all.deb |