{"id":"CVE-2026-68337","state":"PUBLISHED","title":"bpf: Reject redirect helpers without a bpf_net_context","description":"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->bpf_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.","publishedAt":"2026-08-10T12:03:13.583Z","updatedAt":"2026-09-21T13:13:42.530Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3625750f05ecce21a0fce429c1ff85acfffb461b","status":"affected","lessThan":"0f2118b757509332bb0e65f90e5233766f14bb88","versionType":"git"},{"version":"3625750f05ecce21a0fce429c1ff85acfffb461b","status":"affected","lessThan":"aafb093adffad91d4d071e8a7e0dcd9b1d91c94a","versionType":"git"},{"version":"3625750f05ecce21a0fce429c1ff85acfffb461b","status":"affected","lessThan":"cabfacbd5af09d3ae898ca224c4a1459e9bba15d","versionType":"git"},{"version":"3625750f05ecce21a0fce429c1ff85acfffb461b","status":"affected","lessThan":"3f4920d165b29052255527d8ae7619e7ec132ece","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/filter.c","net/sched/cls_api.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.9","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/filter.c","net/sched/cls_api.c"]}],"references":["https://git.kernel.org/stable/c/0f2118b757509332bb0e65f90e5233766f14bb88","https://git.kernel.org/stable/c/aafb093adffad91d4d071e8a7e0dcd9b1d91c94a","https://git.kernel.org/stable/c/cabfacbd5af09d3ae898ca224c4a1459e9bba15d","https://git.kernel.org/stable/c/3f4920d165b29052255527d8ae7619e7ec132ece"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/68xxx/CVE-2026-68337.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68337","state":"PUBLISHED","datePublished":"2026-08-10T12:03:13.583Z","dateUpdated":"2026-09-21T13:13:42.530Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-30T09:28:09.383Z"},"containers":{"cna":{"title":"bpf: Reject redirect helpers without a bpf_net_context","descriptions":[{"lang":"en","value":"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->bpf_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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3625750f05ecce21a0fce429c1ff85acfffb461b","status":"affected","lessThan":"0f2118b757509332bb0e65f90e5233766f14bb88","versionType":"git"},{"version":"3625750f05ecce21a0fce429c1ff85acfffb461b","status":"affected","lessThan":"aafb093adffad91d4d071e8a7e0dcd9b1d91c94a","versionType":"git"},{"version":"3625750f05ecce21a0fce429c1ff85acfffb461b","status":"affected","lessThan":"cabfacbd5af09d3ae898ca224c4a1459e9bba15d","versionType":"git"},{"version":"3625750f05ecce21a0fce429c1ff85acfffb461b","status":"affected","lessThan":"3f4920d165b29052255527d8ae7619e7ec132ece","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/filter.c","net/sched/cls_api.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.9","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/filter.c","net/sched/cls_api.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/0f2118b757509332bb0e65f90e5233766f14bb88"},{"url":"https://git.kernel.org/stable/c/aafb093adffad91d4d071e8a7e0dcd9b1d91c94a"},{"url":"https://git.kernel.org/stable/c/cabfacbd5af09d3ae898ca224c4a1459e9bba15d"},{"url":"https://git.kernel.org/stable/c/3f4920d165b29052255527d8ae7619e7ec132ece"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-09-21T13:13:42.530Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9","versionEndExcluding":"6.12.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}