{ "schema_version": "1.6.1", "id": "RPI-CVE-2024-26589", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2024-26589" ], "published": "2024-02-22T16:14:14Z", "summary": "bpf: Reject variable offset alu on PTR_TO_FLOW_KEYS", "details": "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 \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\".", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:12", "name": "linux" }, "versions": [ "1:6.1.21-1+rpt1", "1:6.1.47-1+rpt2", "1:6.1.47-1+rpt4", "1:6.1.54-1+rpt2", "1:6.1.58-1+rpt2", "1:6.1.63-1+rpt1", "1:6.1.73-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.1.0-rpi1-rpi-v6", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi1-rpi-v7", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi1-rpi-v7l", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi1-rpi-v8", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v6", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v7", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v7l", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v8", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-2712", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v6", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v8", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-2712", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v6", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v7", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v7l", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v8", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-2712", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v6", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v7", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v7l", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v8", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-2712", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v6", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v7", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v7l", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v8", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-2712", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v6", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v7", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v7l", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v8", "binary_version": "1:6.1.73-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.1.21-1+rpt1": { "linux_commit": "0afb5e98488aed7017b9bf321b575d0177feb7ed", "upstream_version": "6.1.21", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.75" }, "1:6.1.47-1+rpt2": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.75" }, "1:6.1.47-1+rpt4": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.75", "compiled_filter": false }, "1:6.1.54-1+rpt2": { "linux_commit": "2906f7abdc03d4a92b6b0e2e0c87ea2a9dffe8f7", "upstream_version": "6.1.54", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.75" }, "1:6.1.58-1+rpt2": { "linux_commit": "ccf1586ad0663fa91238ac56abf6340d6d740d18", "upstream_version": "6.1.58", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.75" }, "1:6.1.63-1+rpt1": { "linux_commit": null, "upstream_version": "6.1.63", "assessment": "upstream version (no usable Linux commit)", "upstream_fixed": "6.1.75" }, "1:6.1.73-1+rpt1": { "linux_commit": null, "upstream_version": "6.1.73", "assessment": "upstream version (no usable Linux commit)", "upstream_fixed": "6.1.75" } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2024-26589" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/29ffa63f21bcdcef3e36b03cccf9d0cd031f6ab0" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/4108b86e324da42f7ed425bd71632fd844300dc8" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/e8d3872b617c21100c5ee4f64e513997a68c2e3d" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/1b500d5d6cecf98dd6ca88bc9e7ae1783c83e6d3" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/22c7fa171a02d310e3a3f6ed46a698ca8a0060ed" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-08-05T11:52:36Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 7.8, "cvss_v3_severity": "High", "scenario": "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 \u00b1512 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 \u2014 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." } } }