{"id":"CVE-2024-26589","state":"PUBLISHED","title":"bpf: Reject variable offset alu on PTR_TO_FLOW_KEYS","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject variable offset alu on PTR_TO_FLOW_KEYS\n\nFor PTR_TO_FLOW_KEYS, check_flow_keys_access() only uses fixed off\nfor validation. However, variable offset ptr alu is not prohibited\nfor this ptr kind. So the variable offset is not checked.\n\nThe following prog is accepted:\n\n  func#0 @0\n  0: R1=ctx() R10=fp0\n  0: (bf) r6 = r1                       ; R1=ctx() R6_w=ctx()\n  1: (79) r7 = *(u64 *)(r6 +144)        ; R6_w=ctx() R7_w=flow_keys()\n  2: (b7) r8 = 1024                     ; R8_w=1024\n  3: (37) r8 /= 1                       ; R8_w=scalar()\n  4: (57) r8 &= 1024                    ; R8_w=scalar(smin=smin32=0,\n  smax=umax=smax32=umax32=1024,var_off=(0x0; 0x400))\n  5: (0f) r7 += r8\n  mark_precise: frame0: last_idx 5 first_idx 0 subseq_idx -1\n  mark_precise: frame0: regs=r8 stack= before 4: (57) r8 &= 1024\n  mark_precise: frame0: regs=r8 stack= before 3: (37) r8 /= 1\n  mark_precise: frame0: regs=r8 stack= before 2: (b7) r8 = 1024\n  6: R7_w=flow_keys(smin=smin32=0,smax=umax=smax32=umax32=1024,var_off\n  =(0x0; 0x400)) R8_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=1024,\n  var_off=(0x0; 0x400))\n  6: (79) r0 = *(u64 *)(r7 +0)          ; R0_w=scalar()\n  7: (95) exit\n\nThis prog loads flow_keys to r7, and adds the variable offset r8\nto r7, and finally causes out-of-bounds access:\n\n  BUG: unable to handle page fault for address: ffffc90014c80038\n  [...]\n  Call Trace:\n   <TASK>\n   bpf_dispatcher_nop_func include/linux/bpf.h:1231 [inline]\n   __bpf_prog_run include/linux/filter.h:651 [inline]\n   bpf_prog_run include/linux/filter.h:658 [inline]\n   bpf_prog_run_pin_on_cpu include/linux/filter.h:675 [inline]\n   bpf_flow_dissect+0x15f/0x350 net/core/flow_dissector.c:991\n   bpf_prog_test_run_flow_dissector+0x39d/0x620 net/bpf/test_run.c:1359\n   bpf_prog_test_run kernel/bpf/syscall.c:4107 [inline]\n   __sys_bpf+0xf8f/0x4560 kernel/bpf/syscall.c:5475\n   __do_sys_bpf kernel/bpf/syscall.c:5561 [inline]\n   __se_sys_bpf kernel/bpf/syscall.c:5559 [inline]\n   __x64_sys_bpf+0x73/0xb0 kernel/bpf/syscall.c:5559\n   do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n   do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:83\n   entry_SYSCALL_64_after_hwframe+0x63/0x6b\n\nFix this by rejecting ptr alu with variable offset on flow_keys.\nApplying the patch rejects the program with \"R7 pointer arithmetic\non flow_keys prohibited\".","publishedAt":"2024-02-22T16:13:33.713Z","updatedAt":"2026-10-30T12:17:42.202Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d58e468b1112dcd1d5193c0a89ff9f98b5a3e8b9","status":"affected","lessThan":"7856cb9f0d795ce518a44c5d135dd932cfbfc656","versionType":"git"},{"version":"d58e468b1112dcd1d5193c0a89ff9f98b5a3e8b9","status":"affected","lessThan":"29ffa63f21bcdcef3e36b03cccf9d0cd031f6ab0","versionType":"git"},{"version":"d58e468b1112dcd1d5193c0a89ff9f98b5a3e8b9","status":"affected","lessThan":"4108b86e324da42f7ed425bd71632fd844300dc8","versionType":"git"},{"version":"d58e468b1112dcd1d5193c0a89ff9f98b5a3e8b9","status":"affected","lessThan":"e8d3872b617c21100c5ee4f64e513997a68c2e3d","versionType":"git"},{"version":"d58e468b1112dcd1d5193c0a89ff9f98b5a3e8b9","status":"affected","lessThan":"1b500d5d6cecf98dd6ca88bc9e7ae1783c83e6d3","versionType":"git"},{"version":"d58e468b1112dcd1d5193c0a89ff9f98b5a3e8b9","status":"affected","lessThan":"22c7fa171a02d310e3a3f6ed46a698ca8a0060ed","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.20","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.20","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.148","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.75","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.14","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.7.2","status":"unaffected","lessThanOrEqual":"6.7.*","versionType":"semver"},{"version":"6.8","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]}],"references":["https://git.kernel.org/stable/c/7856cb9f0d795ce518a44c5d135dd932cfbfc656","https://git.kernel.org/stable/c/29ffa63f21bcdcef3e36b03cccf9d0cd031f6ab0","https://git.kernel.org/stable/c/4108b86e324da42f7ed425bd71632fd844300dc8","https://git.kernel.org/stable/c/e8d3872b617c21100c5ee4f64e513997a68c2e3d","https://git.kernel.org/stable/c/1b500d5d6cecf98dd6ca88bc9e7ae1783c83e6d3","https://git.kernel.org/stable/c/22c7fa171a02d310e3a3f6ed46a698ca8a0060ed"],"weaknesses":[],"ingestedAt":"2026-10-30T12:34:06.950Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/26xxx/CVE-2024-26589.json","commit":"db8103c5921aac81d5d90efcf3745980dafabf49","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-26589","state":"PUBLISHED","datePublished":"2024-02-22T16:13:33.713Z","dateUpdated":"2026-10-30T12:17:42.202Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-02-19T14:20:24.126Z"},"containers":{"cna":{"title":"bpf: Reject variable offset alu on PTR_TO_FLOW_KEYS","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject variable offset alu on PTR_TO_FLOW_KEYS\n\nFor PTR_TO_FLOW_KEYS, check_flow_keys_access() only uses fixed off\nfor validation. However, variable offset ptr alu is not prohibited\nfor this ptr kind. So the variable offset is not checked.\n\nThe following prog is accepted:\n\n  func#0 @0\n  0: R1=ctx() R10=fp0\n  0: (bf) r6 = r1                       ; R1=ctx() R6_w=ctx()\n  1: (79) r7 = *(u64 *)(r6 +144)        ; R6_w=ctx() R7_w=flow_keys()\n  2: (b7) r8 = 1024                     ; R8_w=1024\n  3: (37) r8 /= 1                       ; R8_w=scalar()\n  4: (57) r8 &= 1024                    ; R8_w=scalar(smin=smin32=0,\n  smax=umax=smax32=umax32=1024,var_off=(0x0; 0x400))\n  5: (0f) r7 += r8\n  mark_precise: frame0: last_idx 5 first_idx 0 subseq_idx -1\n  mark_precise: frame0: regs=r8 stack= before 4: (57) r8 &= 1024\n  mark_precise: frame0: regs=r8 stack= before 3: (37) r8 /= 1\n  mark_precise: frame0: regs=r8 stack= before 2: (b7) r8 = 1024\n  6: R7_w=flow_keys(smin=smin32=0,smax=umax=smax32=umax32=1024,var_off\n  =(0x0; 0x400)) R8_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=1024,\n  var_off=(0x0; 0x400))\n  6: (79) r0 = *(u64 *)(r7 +0)          ; R0_w=scalar()\n  7: (95) exit\n\nThis prog loads flow_keys to r7, and adds the variable offset r8\nto r7, and finally causes out-of-bounds access:\n\n  BUG: unable to handle page fault for address: ffffc90014c80038\n  [...]\n  Call Trace:\n   <TASK>\n   bpf_dispatcher_nop_func include/linux/bpf.h:1231 [inline]\n   __bpf_prog_run include/linux/filter.h:651 [inline]\n   bpf_prog_run include/linux/filter.h:658 [inline]\n   bpf_prog_run_pin_on_cpu include/linux/filter.h:675 [inline]\n   bpf_flow_dissect+0x15f/0x350 net/core/flow_dissector.c:991\n   bpf_prog_test_run_flow_dissector+0x39d/0x620 net/bpf/test_run.c:1359\n   bpf_prog_test_run kernel/bpf/syscall.c:4107 [inline]\n   __sys_bpf+0xf8f/0x4560 kernel/bpf/syscall.c:5475\n   __do_sys_bpf kernel/bpf/syscall.c:5561 [inline]\n   __se_sys_bpf kernel/bpf/syscall.c:5559 [inline]\n   __x64_sys_bpf+0x73/0xb0 kernel/bpf/syscall.c:5559\n   do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n   do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:83\n   entry_SYSCALL_64_after_hwframe+0x63/0x6b\n\nFix this by rejecting ptr alu with variable offset on flow_keys.\nApplying the patch rejects the program with \"R7 pointer arithmetic\non flow_keys prohibited\"."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d58e468b1112dcd1d5193c0a89ff9f98b5a3e8b9","status":"affected","lessThan":"7856cb9f0d795ce518a44c5d135dd932cfbfc656","versionType":"git"},{"version":"d58e468b1112dcd1d5193c0a89ff9f98b5a3e8b9","status":"affected","lessThan":"29ffa63f21bcdcef3e36b03cccf9d0cd031f6ab0","versionType":"git"},{"version":"d58e468b1112dcd1d5193c0a89ff9f98b5a3e8b9","status":"affected","lessThan":"4108b86e324da42f7ed425bd71632fd844300dc8","versionType":"git"},{"version":"d58e468b1112dcd1d5193c0a89ff9f98b5a3e8b9","status":"affected","lessThan":"e8d3872b617c21100c5ee4f64e513997a68c2e3d","versionType":"git"},{"version":"d58e468b1112dcd1d5193c0a89ff9f98b5a3e8b9","status":"affected","lessThan":"1b500d5d6cecf98dd6ca88bc9e7ae1783c83e6d3","versionType":"git"},{"version":"d58e468b1112dcd1d5193c0a89ff9f98b5a3e8b9","status":"affected","lessThan":"22c7fa171a02d310e3a3f6ed46a698ca8a0060ed","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.20","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.20","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.148","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.75","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.14","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.7.2","status":"unaffected","lessThanOrEqual":"6.7.*","versionType":"semver"},{"version":"6.8","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/7856cb9f0d795ce518a44c5d135dd932cfbfc656"},{"url":"https://git.kernel.org/stable/c/29ffa63f21bcdcef3e36b03cccf9d0cd031f6ab0"},{"url":"https://git.kernel.org/stable/c/4108b86e324da42f7ed425bd71632fd844300dc8"},{"url":"https://git.kernel.org/stable/c/e8d3872b617c21100c5ee4f64e513997a68c2e3d"},{"url":"https://git.kernel.org/stable/c/1b500d5d6cecf98dd6ca88bc9e7ae1783c83e6d3"},{"url":"https://git.kernel.org/stable/c/22c7fa171a02d310e3a3f6ed46a698ca8a0060ed"}],"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 - The vulnerability is reached by loading a crafted eBPF program via the bpf(2) syscall and triggering it with BPF_PROG_TEST_RUN (or by attaching it to a netns), all of which require local access to the system. No remote packet path reaches the flawed verifier logic without the attacker first loading the program locally.\nAC:L - The malicious program is accepted deterministically by the verifier and the out-of-bounds offset and stored data are entirely under the attacker's control at runtime; there is no race, no memory-layout guessing, and no dependence on any condition outside the attacker's influence.\nPR:L - Loading a BPF_PROG_TYPE_FLOW_DISSECTOR program requires CAP_BPF and CAP_NET_ADMIN, which are routinely granted to non-root, confined container workloads (CNI/eBPF networking and observability sidecars) that hold no administrative control over the host; triggering the program afterwards via BPF_PROG_TEST_RUN requires no capability check at all.\nUI:N - The attacker loads and executes the program entirely on their own; no action by any other user or administrator is needed.\nS:U - The out-of-bounds access corrupts kernel memory within the same kernel security authority; there is no hypervisor, IOMMU, or other trust boundary crossed.\nC:H - The variable offset permits BPF loads at an attacker-chosen offset (up to ±512 MB) from a kernel stack buffer, and the read values are returned to userspace through bpf_test_finish(), yielding arbitrary kernel memory disclosure including pointers needed to defeat KASLR.\nI:H - check_mem_access() permits BPF_WRITE of attacker-controlled scalars through PTR_TO_FLOW_KEYS, so the same unchecked variable offset gives an out-of-bounds kernel stack write — overwriting saved return addresses or adjacent kernel data for control-flow hijack and privilege escalation.\nA:H - The reported syzkaller reproducer already produces an unhandled kernel page fault (\"BUG: unable to handle page fault for address: ffffc90014c80038\") in bpf_flow_dissect(), and out-of-bounds stack writes reliably panic the kernel."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:17:42.202Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"5.15.148"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.1.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.6.14"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.7.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.8"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2024-26589","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-02-22T19:09:08.259778Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-07-05T17:21:01.815Z"}},{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/29ffa63f21bcdcef3e36b03cccf9d0cd031f6ab0","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/4108b86e324da42f7ed425bd71632fd844300dc8","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/e8d3872b617c21100c5ee4f64e513997a68c2e3d","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/1b500d5d6cecf98dd6ca88bc9e7ae1783c83e6d3","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/22c7fa171a02d310e3a3f6ed46a698ca8a0060ed","tags":["x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-02T00:07:19.728Z"}}]}}}