{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "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": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "kernel/bpf/verifier.c"
               ],
               "versions": [
                  {
                     "version": "d58e468b1112",
                     "lessThan": "29ffa63f21bc",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d58e468b1112",
                     "lessThan": "4108b86e324d",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d58e468b1112",
                     "lessThan": "e8d3872b617c",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d58e468b1112",
                     "lessThan": "1b500d5d6cec",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d58e468b1112",
                     "lessThan": "22c7fa171a02",
                     "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/verifier.c"
               ],
               "versions": [
                  {
                     "version": "4.20",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "4.20",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.15.148",
                     "lessThanOrEqual": "5.15.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.1.75",
                     "lessThanOrEqual": "6.1.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.6.14",
                     "lessThanOrEqual": "6.6.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.7.2",
                     "lessThanOrEqual": "6.7.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.8",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "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"
            }
         ],
         "title": "bpf: Reject variable offset alu on PTR_TO_FLOW_KEYS",
         "x_generator": {
            "engine": "bippy-a5840b7849dd"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2024-26589",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}