{"cve":"CVE-2024-26589","nvd":{"published":"2024-02-22T17:15:09.050","modified":"2026-10-30T13:17:20.200","status":"Modified","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\".","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-119"],"references":["https://git.kernel.org/stable/c/1b500d5d6cecf98dd6ca88bc9e7ae1783c83e6d3","https://git.kernel.org/stable/c/22c7fa171a02d310e3a3f6ed46a698ca8a0060ed","https://git.kernel.org/stable/c/29ffa63f21bcdcef3e36b03cccf9d0cd031f6ab0","https://git.kernel.org/stable/c/4108b86e324da42f7ed425bd71632fd844300dc8","https://git.kernel.org/stable/c/7856cb9f0d795ce518a44c5d135dd932cfbfc656"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-30T13:47:47.119061695+00:00"},"epss":{"cve":"CVE-2024-26589","score":0.00239,"percentile":0.15,"date":"2026-10-30"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}