{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89799", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.767Z", "datePublished": "2026-09-16T10:30:31.487Z", "dateUpdated": "2026-10-19T08:52:53.972Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:52:53.972Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Disable preemption in bpf_get_stackid\n\nThe get_perf_callchain call needs disabled preemption plus we need\nit disabled as long as we access its returned trace entries buffer.\n\nNote the bpf_get_stackid_pe function is executed already with\npreemption disabled." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - bpf_get_stackid is a tracing BPF helper (kprobe, tracepoint, raw_tp, perf_event, tracing/fentry) reached only after a local bpf(2) PROG_LOAD and attach; kernel CNA guidance classifies BPF as Local, with no network or USB path into this helper.\nAC:L - The attacker controls both sides of the race: a preemptible raw_tp/tracing program with a small STACK_TRACE map, and a same-CPU get_perf_callchain with larger max_depth that reuses the per-CPU entry after put_callchain_entry(). On PREEMPT kernels (e.g. Android) raw_tp uses migrate_disable only, so pinning and retries make the window reliably hittable.\nPR:L - Loading the required tracing programs needs CAP_BPF and CAP_PERFMON at bpf_prog_load(), and STACK_TRACE maps need CAP_BPF. Per kernel CNA guidance these are Low because BPF tokens and user namespaces can delegate them to non-init-namespace users, not only real root.\nUI:N - The attacker loads their own BPF program, attaches it to a tracepoint they can fire, and invokes bpf_get_stackid through their own syscalls or pinned threads; no victim mount, file open, or other user action is required.\nS:U - The out-of-bounds write corrupts the stack-map bucket slab inside the same host kernel security authority, enabling local privilege escalation; it does not cross a VM, IOMMU, or other distinct trust boundary.\nC:H - After put_callchain_entry(), a reused per-CPU entry can inflate trace->nr so memcpy/jhash2 and the build-id loop copy kernel instruction pointers past the attacker-sized stack_map_bucket, which is kernel memory corruption that can be turned into an arbitrary read primitive.\nI:H - Without a remaining size cap on the reused trace->nr, memcpy into the preallocated stack_map_bucket (sized to a small map value_size) or the bpf_stack_build_id store loop is an attacker-sized kernel heap OOB write, up to PERF_MAX_STACK_DEPTH frames, that can smash adjacent slab and hijack control flow.\nA:H - The same unbounded heap write past a small stack-map bucket causes a kernel oops or panic even when not fully weaponized, matching CNA guidance that any kernel crash or memory-corrupting OOB write is Availability High." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/bpf/stackmap.c" ], "versions": [ { "version": "d5a3b1f691865be576c2bffa708549b8cdccda19", "lessThan": "18c71e4b65ee60b8611fc071bdd7159f10185117", "status": "affected", "versionType": "git" }, { "version": "d5a3b1f691865be576c2bffa708549b8cdccda19", "lessThan": "ccf481d73bce6e851cec364fe831c86fe66877cf", "status": "affected", "versionType": "git" }, { "version": "d5a3b1f691865be576c2bffa708549b8cdccda19", "lessThan": "c4efdc1d4cb3e9183e41a1b2a5e0901dbbb31cdf", "status": "affected", "versionType": "git" }, { "version": "d5a3b1f691865be576c2bffa708549b8cdccda19", "lessThan": "15f1bd8574662f1b7b26aaa2e23ebf4066f0117d", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/bpf/stackmap.c" ], "versions": [ { "version": "4.6", "status": "affected" }, { "version": "0", "lessThan": "4.6", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.51", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.5", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "6.12.111" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "6.18.51" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "7.2.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/18c71e4b65ee60b8611fc071bdd7159f10185117" }, { "url": "https://git.kernel.org/stable/c/ccf481d73bce6e851cec364fe831c86fe66877cf" }, { "url": "https://git.kernel.org/stable/c/c4efdc1d4cb3e9183e41a1b2a5e0901dbbb31cdf" }, { "url": "https://git.kernel.org/stable/c/15f1bd8574662f1b7b26aaa2e23ebf4066f0117d" } ], "title": "bpf: Disable preemption in bpf_get_stackid", "x_generator": { "engine": "bippy-1.2.0" } } } }