A use-after-free vulnerability in the Linux kernel’s net/sched: cls_fw component can be exploited to achieve local privilege escalation. When fw_change() is called on an existing filter, the whole tcf_result struct is always copied into the new instance of the filter. This causes a problem when updating a filter bound to a class, as tcf_unbind_filter() is always called on the old instance in the success path, decreasing filter_cnt of the still referenced class and allowing it to be deleted, leading to a use-after-free. We recommend upgrading past commit 76e42ae831991c828cffa8c37736ebfb831ad5ec.
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
Debian | 12 | all | linux | < 6.1.52-1 | linux_6.1.52-1_all.deb |
Debian | 11 | all | linux | < 5.10.191-1 | linux_5.10.191-1_all.deb |
Debian | 10 | all | linux | < 4.19.304-1 | linux_4.19.304-1_all.deb |
Debian | 999 | all | linux | < 6.4.11-1 | linux_6.4.11-1_all.deb |
Debian | 13 | all | linux | < 6.4.11-1 | linux_6.4.11-1_all.deb |