{"id":"AZL-94701","summary":"CVE-2026-68337 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject redirect helpers without a bpf_net_context\n\nThe bpf_redirect*() helpers and skb_do_redirect() obtain the per-task\nbpf_redirect_info via bpf_net_ctx_get_ri(), which dereferences the\ncurrent-\u003ebpf_net_context unconditionally. That context is established\non the paths that run tc BPF such as sch_handle_{ingress,egress}(),\n*except* for the case where {cls,act}_bpf was attached to a proper\nqdisc. A program running from there reaches the NULL deref in two ways:\n\n* It calls bpf_redirect() directly, which dereferences the context at\n  the top of the helper:\n\n     tc qdisc add dev eth0 root handle 1: red limit 1MB min 10KB max 20KB \\\n        avpkt 1000 burst 100 qevent early_drop block 10\n     tc filter add block 10 pref 1 bpf obj redirect.o\n\n* It simply returns TC_ACT_REDIRECT without helper call: tcf_qevent_handle()\n  then dispatches to skb_do_redirect(), which dereferences the context\n\nRather than extending bpf_net_context management into the qdisc path,\nmake the redirect helpers refuse to operate when no context exists, and\nhave tcf_qevent_handle() drop a TC_ACT_REDIRECT verdict instead of\ncalling skb_do_redirect(). Previous behaviour was a crash, so nothing\nregresses by not supporting it.","modified":"2026-08-31T05:26:27Z","published":"2026-08-10T13:20:24Z","upstream":["CVE-2026-68337"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68337"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-94701.json"}}],"schema_version":"1.9.0"}