CVE-2024-57996 (GCVE-0-2024-57996)
Vulnerability from cvelistv5
Published
2025-02-27 02:07
Modified
2025-08-28 14:42
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: net_sched: sch_sfq: don't allow 1 packet limit The current implementation does not work correctly with a limit of 1. iproute2 actually checks for this and this patch adds the check in kernel as well. This fixes the following syzkaller reported crash: UBSAN: array-index-out-of-bounds in net/sched/sch_sfq.c:210:6 index 65535 is out of range for type 'struct sfq_head[128]' CPU: 0 PID: 2569 Comm: syz-executor101 Not tainted 5.10.0-smp-DEV #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x125/0x19f lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:148 [inline] __ubsan_handle_out_of_bounds+0xed/0x120 lib/ubsan.c:347 sfq_link net/sched/sch_sfq.c:210 [inline] sfq_dec+0x528/0x600 net/sched/sch_sfq.c:238 sfq_dequeue+0x39b/0x9d0 net/sched/sch_sfq.c:500 sfq_reset+0x13/0x50 net/sched/sch_sfq.c:525 qdisc_reset+0xfe/0x510 net/sched/sch_generic.c:1026 tbf_reset+0x3d/0x100 net/sched/sch_tbf.c:319 qdisc_reset+0xfe/0x510 net/sched/sch_generic.c:1026 dev_reset_queue+0x8c/0x140 net/sched/sch_generic.c:1296 netdev_for_each_tx_queue include/linux/netdevice.h:2350 [inline] dev_deactivate_many+0x6dc/0xc20 net/sched/sch_generic.c:1362 __dev_close_many+0x214/0x350 net/core/dev.c:1468 dev_close_many+0x207/0x510 net/core/dev.c:1506 unregister_netdevice_many+0x40f/0x16b0 net/core/dev.c:10738 unregister_netdevice_queue+0x2be/0x310 net/core/dev.c:10695 unregister_netdevice include/linux/netdevice.h:2893 [inline] __tun_detach+0x6b6/0x1600 drivers/net/tun.c:689 tun_detach drivers/net/tun.c:705 [inline] tun_chr_close+0x104/0x1b0 drivers/net/tun.c:3640 __fput+0x203/0x840 fs/file_table.c:280 task_work_run+0x129/0x1b0 kernel/task_work.c:185 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x5ce/0x2200 kernel/exit.c:931 do_group_exit+0x144/0x310 kernel/exit.c:1046 __do_sys_exit_group kernel/exit.c:1057 [inline] __se_sys_exit_group kernel/exit.c:1055 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1055 do_syscall_64+0x6c/0xd0 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fe5e7b52479 Code: Unable to access opcode bytes at RIP 0x7fe5e7b5244f. RSP: 002b:00007ffd3c800398 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe5e7b52479 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 00007fe5e7bcd2d0 R08: ffffffffffffffb8 R09: 0000000000000014 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe5e7bcd2d0 R13: 0000000000000000 R14: 00007fe5e7bcdd20 R15: 00007fe5e7b24270 The crash can be also be reproduced with the following (with a tc recompiled to allow for sfq limits of 1): tc qdisc add dev dummy0 handle 1: root tbf rate 1Kbit burst 100b lat 1s ../iproute2-6.9.0/tc/tc qdisc add dev dummy0 handle 2: parent 1:10 sfq limit 1 ifconfig dummy0 up ping -I dummy0 -f -c2 -W0.1 8.8.8.8 sleep 1 Scenario that triggers the crash: * the first packet is sent and queued in TBF and SFQ; qdisc qlen is 1 * TBF dequeues: it peeks from SFQ which moves the packet to the gso_skb list and keeps qdisc qlen set to 1. TBF is out of tokens so it schedules itself for later. * the second packet is sent and TBF tries to queues it to SFQ. qdisc qlen is now 2 and because the SFQ limit is 1 the packet is dropped by SFQ. At this point qlen is 1, and all of the SFQ slots are empty, however q->tail is not NULL. At this point, assuming no more packets are queued, when sch_dequeue runs again it will decrement the qlen for the current empty slot causing an underflow and the subsequent out of bounds access.
Impacted products
Vendor Product Version
Linux Linux Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Create a notification for this product.
   Linux Linux Version: 2.6.12
Create a notification for this product.
Show details on NVD website


{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sched/sch_sfq.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "e12f6013d0a69660e8b99bfe381b9546ae667328",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "1e6d9d87626cf89eeffb4d943db12cb5b10bf961",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "1b562b7f9231432da40d12e19786c1bd7df653a7",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "35d0137305ae2f97260a9047f445bd4434bd6cc7",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "833e9a1c27b82024db7ff5038a51651f48f05e5e",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "7d8947f2153ee9c5ab4cb17861a11cc45f30e8c4",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "7fefc294204f10a3405f175f4ac2be16d63f135e",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "10685681bafce6febb39770f3387621bf5d67d0b",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sched/sch_sfq.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.12"
            },
            {
              "lessThan": "2.6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.4.*",
              "status": "unaffected",
              "version": "5.4.297",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.239",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.186",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.129",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.76",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.13",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.13.*",
              "status": "unaffected",
              "version": "6.13.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.14",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.4.297",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.239",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.186",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.129",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.76",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.13",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.13.2",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.14",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet_sched: sch_sfq: don\u0027t allow 1 packet limit\n\nThe current implementation does not work correctly with a limit of\n1. iproute2 actually checks for this and this patch adds the check in\nkernel as well.\n\nThis fixes the following syzkaller reported crash:\n\nUBSAN: array-index-out-of-bounds in net/sched/sch_sfq.c:210:6\nindex 65535 is out of range for type \u0027struct sfq_head[128]\u0027\nCPU: 0 PID: 2569 Comm: syz-executor101 Not tainted 5.10.0-smp-DEV #1\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024\nCall Trace:\n  __dump_stack lib/dump_stack.c:79 [inline]\n  dump_stack+0x125/0x19f lib/dump_stack.c:120\n  ubsan_epilogue lib/ubsan.c:148 [inline]\n  __ubsan_handle_out_of_bounds+0xed/0x120 lib/ubsan.c:347\n  sfq_link net/sched/sch_sfq.c:210 [inline]\n  sfq_dec+0x528/0x600 net/sched/sch_sfq.c:238\n  sfq_dequeue+0x39b/0x9d0 net/sched/sch_sfq.c:500\n  sfq_reset+0x13/0x50 net/sched/sch_sfq.c:525\n  qdisc_reset+0xfe/0x510 net/sched/sch_generic.c:1026\n  tbf_reset+0x3d/0x100 net/sched/sch_tbf.c:319\n  qdisc_reset+0xfe/0x510 net/sched/sch_generic.c:1026\n  dev_reset_queue+0x8c/0x140 net/sched/sch_generic.c:1296\n  netdev_for_each_tx_queue include/linux/netdevice.h:2350 [inline]\n  dev_deactivate_many+0x6dc/0xc20 net/sched/sch_generic.c:1362\n  __dev_close_many+0x214/0x350 net/core/dev.c:1468\n  dev_close_many+0x207/0x510 net/core/dev.c:1506\n  unregister_netdevice_many+0x40f/0x16b0 net/core/dev.c:10738\n  unregister_netdevice_queue+0x2be/0x310 net/core/dev.c:10695\n  unregister_netdevice include/linux/netdevice.h:2893 [inline]\n  __tun_detach+0x6b6/0x1600 drivers/net/tun.c:689\n  tun_detach drivers/net/tun.c:705 [inline]\n  tun_chr_close+0x104/0x1b0 drivers/net/tun.c:3640\n  __fput+0x203/0x840 fs/file_table.c:280\n  task_work_run+0x129/0x1b0 kernel/task_work.c:185\n  exit_task_work include/linux/task_work.h:33 [inline]\n  do_exit+0x5ce/0x2200 kernel/exit.c:931\n  do_group_exit+0x144/0x310 kernel/exit.c:1046\n  __do_sys_exit_group kernel/exit.c:1057 [inline]\n  __se_sys_exit_group kernel/exit.c:1055 [inline]\n  __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1055\n do_syscall_64+0x6c/0xd0\n entry_SYSCALL_64_after_hwframe+0x61/0xcb\nRIP: 0033:0x7fe5e7b52479\nCode: Unable to access opcode bytes at RIP 0x7fe5e7b5244f.\nRSP: 002b:00007ffd3c800398 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7\nRAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe5e7b52479\nRDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000\nRBP: 00007fe5e7bcd2d0 R08: ffffffffffffffb8 R09: 0000000000000014\nR10: 0000000000000000 R11: 0000000000000246 R12: 00007fe5e7bcd2d0\nR13: 0000000000000000 R14: 00007fe5e7bcdd20 R15: 00007fe5e7b24270\n\nThe crash can be also be reproduced with the following (with a tc\nrecompiled to allow for sfq limits of 1):\n\ntc qdisc add dev dummy0 handle 1: root tbf rate 1Kbit burst 100b lat 1s\n../iproute2-6.9.0/tc/tc qdisc add dev dummy0 handle 2: parent 1:10 sfq limit 1\nifconfig dummy0 up\nping -I dummy0 -f -c2 -W0.1 8.8.8.8\nsleep 1\n\nScenario that triggers the crash:\n\n* the first packet is sent and queued in TBF and SFQ; qdisc qlen is 1\n\n* TBF dequeues: it peeks from SFQ which moves the packet to the\n  gso_skb list and keeps qdisc qlen set to 1. TBF is out of tokens so\n  it schedules itself for later.\n\n* the second packet is sent and TBF tries to queues it to SFQ. qdisc\n  qlen is now 2 and because the SFQ limit is 1 the packet is dropped\n  by SFQ. At this point qlen is 1, and all of the SFQ slots are empty,\n  however q-\u003etail is not NULL.\n\nAt this point, assuming no more packets are queued, when sch_dequeue\nruns again it will decrement the qlen for the current empty slot\ncausing an underflow and the subsequent out of bounds access."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-08-28T14:42:44.697Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/e12f6013d0a69660e8b99bfe381b9546ae667328"
        },
        {
          "url": "https://git.kernel.org/stable/c/1e6d9d87626cf89eeffb4d943db12cb5b10bf961"
        },
        {
          "url": "https://git.kernel.org/stable/c/1b562b7f9231432da40d12e19786c1bd7df653a7"
        },
        {
          "url": "https://git.kernel.org/stable/c/35d0137305ae2f97260a9047f445bd4434bd6cc7"
        },
        {
          "url": "https://git.kernel.org/stable/c/833e9a1c27b82024db7ff5038a51651f48f05e5e"
        },
        {
          "url": "https://git.kernel.org/stable/c/7d8947f2153ee9c5ab4cb17861a11cc45f30e8c4"
        },
        {
          "url": "https://git.kernel.org/stable/c/7fefc294204f10a3405f175f4ac2be16d63f135e"
        },
        {
          "url": "https://git.kernel.org/stable/c/10685681bafce6febb39770f3387621bf5d67d0b"
        }
      ],
      "title": "net_sched: sch_sfq: don\u0027t allow 1 packet limit",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2024-57996",
    "datePublished": "2025-02-27T02:07:16.765Z",
    "dateReserved": "2025-02-27T02:04:28.914Z",
    "dateUpdated": "2025-08-28T14:42:44.697Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2024-57996\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-02-27T02:15:13.620\",\"lastModified\":\"2025-08-28T15:15:43.433\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nnet_sched: sch_sfq: don\u0027t allow 1 packet limit\\n\\nThe current implementation does not work correctly with a limit of\\n1. iproute2 actually checks for this and this patch adds the check in\\nkernel as well.\\n\\nThis fixes the following syzkaller reported crash:\\n\\nUBSAN: array-index-out-of-bounds in net/sched/sch_sfq.c:210:6\\nindex 65535 is out of range for type \u0027struct sfq_head[128]\u0027\\nCPU: 0 PID: 2569 Comm: syz-executor101 Not tainted 5.10.0-smp-DEV #1\\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024\\nCall Trace:\\n  __dump_stack lib/dump_stack.c:79 [inline]\\n  dump_stack+0x125/0x19f lib/dump_stack.c:120\\n  ubsan_epilogue lib/ubsan.c:148 [inline]\\n  __ubsan_handle_out_of_bounds+0xed/0x120 lib/ubsan.c:347\\n  sfq_link net/sched/sch_sfq.c:210 [inline]\\n  sfq_dec+0x528/0x600 net/sched/sch_sfq.c:238\\n  sfq_dequeue+0x39b/0x9d0 net/sched/sch_sfq.c:500\\n  sfq_reset+0x13/0x50 net/sched/sch_sfq.c:525\\n  qdisc_reset+0xfe/0x510 net/sched/sch_generic.c:1026\\n  tbf_reset+0x3d/0x100 net/sched/sch_tbf.c:319\\n  qdisc_reset+0xfe/0x510 net/sched/sch_generic.c:1026\\n  dev_reset_queue+0x8c/0x140 net/sched/sch_generic.c:1296\\n  netdev_for_each_tx_queue include/linux/netdevice.h:2350 [inline]\\n  dev_deactivate_many+0x6dc/0xc20 net/sched/sch_generic.c:1362\\n  __dev_close_many+0x214/0x350 net/core/dev.c:1468\\n  dev_close_many+0x207/0x510 net/core/dev.c:1506\\n  unregister_netdevice_many+0x40f/0x16b0 net/core/dev.c:10738\\n  unregister_netdevice_queue+0x2be/0x310 net/core/dev.c:10695\\n  unregister_netdevice include/linux/netdevice.h:2893 [inline]\\n  __tun_detach+0x6b6/0x1600 drivers/net/tun.c:689\\n  tun_detach drivers/net/tun.c:705 [inline]\\n  tun_chr_close+0x104/0x1b0 drivers/net/tun.c:3640\\n  __fput+0x203/0x840 fs/file_table.c:280\\n  task_work_run+0x129/0x1b0 kernel/task_work.c:185\\n  exit_task_work include/linux/task_work.h:33 [inline]\\n  do_exit+0x5ce/0x2200 kernel/exit.c:931\\n  do_group_exit+0x144/0x310 kernel/exit.c:1046\\n  __do_sys_exit_group kernel/exit.c:1057 [inline]\\n  __se_sys_exit_group kernel/exit.c:1055 [inline]\\n  __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1055\\n do_syscall_64+0x6c/0xd0\\n entry_SYSCALL_64_after_hwframe+0x61/0xcb\\nRIP: 0033:0x7fe5e7b52479\\nCode: Unable to access opcode bytes at RIP 0x7fe5e7b5244f.\\nRSP: 002b:00007ffd3c800398 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7\\nRAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe5e7b52479\\nRDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000\\nRBP: 00007fe5e7bcd2d0 R08: ffffffffffffffb8 R09: 0000000000000014\\nR10: 0000000000000000 R11: 0000000000000246 R12: 00007fe5e7bcd2d0\\nR13: 0000000000000000 R14: 00007fe5e7bcdd20 R15: 00007fe5e7b24270\\n\\nThe crash can be also be reproduced with the following (with a tc\\nrecompiled to allow for sfq limits of 1):\\n\\ntc qdisc add dev dummy0 handle 1: root tbf rate 1Kbit burst 100b lat 1s\\n../iproute2-6.9.0/tc/tc qdisc add dev dummy0 handle 2: parent 1:10 sfq limit 1\\nifconfig dummy0 up\\nping -I dummy0 -f -c2 -W0.1 8.8.8.8\\nsleep 1\\n\\nScenario that triggers the crash:\\n\\n* the first packet is sent and queued in TBF and SFQ; qdisc qlen is 1\\n\\n* TBF dequeues: it peeks from SFQ which moves the packet to the\\n  gso_skb list and keeps qdisc qlen set to 1. TBF is out of tokens so\\n  it schedules itself for later.\\n\\n* the second packet is sent and TBF tries to queues it to SFQ. qdisc\\n  qlen is now 2 and because the SFQ limit is 1 the packet is dropped\\n  by SFQ. At this point qlen is 1, and all of the SFQ slots are empty,\\n  however q-\u003etail is not NULL.\\n\\nAt this point, assuming no more packets are queued, when sch_dequeue\\nruns again it will decrement the qlen for the current empty slot\\ncausing an underflow and the subsequent out of bounds access.\"},{\"lang\":\"es\",\"value\":\"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net_sched: sch_sfq: no permitir l\u00edmite de 1 paquete La implementaci\u00f3n actual no funciona correctamente con un l\u00edmite de 1. iproute2 en realidad verifica esto y este parche tambi\u00e9n agrega la verificaci\u00f3n en el kernel. Esto corrige el siguiente fallo informado por syzkaller reported crash: UBSAN: array-index-out-of-bounds in net/sched/sch_sfq.c:210:6 index 65535 is out of range for type \u0027struct sfq_head[128]\u0027 CPU: 0 PID: 2569 Comm: syz-executor101 Not tainted 5.10.0-smp-DEV #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x125/0x19f lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:148 [inline] __ubsan_handle_out_of_bounds+0xed/0x120 lib/ubsan.c:347 sfq_link net/sched/sch_sfq.c:210 [inline] sfq_dec+0x528/0x600 net/sched/sch_sfq.c:238 sfq_dequeue+0x39b/0x9d0 net/sched/sch_sfq.c:500 sfq_reset+0x13/0x50 net/sched/sch_sfq.c:525 qdisc_reset+0xfe/0x510 net/sched/sch_generic.c:1026 tbf_reset+0x3d/0x100 net/sched/sch_tbf.c:319 qdisc_reset+0xfe/0x510 net/sched/sch_generic.c:1026 dev_reset_queue+0x8c/0x140 net/sched/sch_generic.c:1296 netdev_for_each_tx_queue include/linux/netdevice.h:2350 [inline] dev_deactivate_many+0x6dc/0xc20 net/sched/sch_generic.c:1362 __dev_close_many+0x214/0x350 net/core/dev.c:1468 dev_close_many+0x207/0x510 net/core/dev.c:1506 unregister_netdevice_many+0x40f/0x16b0 net/core/dev.c:10738 unregister_netdevice_queue+0x2be/0x310 net/core/dev.c:10695 unregister_netdevice include/linux/netdevice.h:2893 [inline] __tun_detach+0x6b6/0x1600 drivers/net/tun.c:689 tun_detach drivers/net/tun.c:705 [inline] tun_chr_close+0x104/0x1b0 drivers/net/tun.c:3640 __fput+0x203/0x840 fs/file_table.c:280 task_work_run+0x129/0x1b0 kernel/task_work.c:185 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x5ce/0x2200 kernel/exit.c:931 do_group_exit+0x144/0x310 kernel/exit.c:1046 __do_sys_exit_group kernel/exit.c:1057 [inline] __se_sys_exit_group kernel/exit.c:1055 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1055 do_syscall_64+0x6c/0xd0 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fe5e7b52479 Code: Unable to access opcode bytes at RIP 0x7fe5e7b5244f. RSP: 002b:00007ffd3c800398 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe5e7b52479 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 00007fe5e7bcd2d0 R08: ffffffffffffffb8 R09: 0000000000000014 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe5e7bcd2d0 R13: 0000000000000000 R14: 00007fe5e7bcdd20 R15: 00007fe5e7b24270 The crash can be also be reproduced with the following (with a tc recompiled to allow for sfq limits of 1): tc qdisc add dev dummy0 handle 1: root tbf rate 1Kbit burst 100b lat 1s ../iproute2-6.9.0/tc/tc qdisc add dev dummy0 handle 2: parent 1:10 sfq limit 1 ifconfig dummy0 up ping -I dummy0 -f -c2 -W0.1 8.8.8.8 sleep 1 Scenario that triggers the crash: * the first packet is sent and queued in TBF and SFQ; qdisc qlen is 1 * TBF dequeues: it peeks from SFQ which moves the packet to the gso_skb list and keeps qdisc qlen set to 1. TBF is out of tokens so it schedules itself for later. * the second packet is sent and TBF tries to queues it to SFQ. qdisc qlen is now 2 and because the SFQ limit is 1 the packet is dropped by SFQ. At this point qlen is 1, and all of the SFQ slots are empty, however q-\u0026gt;tail is not NULL. En este punto, asumiendo que no hay m\u00e1s paquetes en cola, cuando sch_dequeue se ejecute nuevamente, disminuir\u00e1 el qlen para la ranura vac\u00eda actual, lo que provocar\u00e1 un desbordamiento y el posterior acceso fuera de l\u00edmites.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":5.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-129\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"2.6.12\",\"versionEndExcluding\":\"6.1.129\",\"matchCriteriaId\":\"7CFA9ED9-656E-463E-A661-B2C4369D63EB\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.2\",\"versionEndExcluding\":\"6.6.76\",\"matchCriteriaId\":\"A6D70701-9CB6-4222-A957-00A419878993\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.7\",\"versionEndExcluding\":\"6.12.13\",\"matchCriteriaId\":\"2897389C-A8C3-4D69-90F2-E701B3D66373\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.13\",\"versionEndExcluding\":\"6.13.2\",\"matchCriteriaId\":\"6D4116B1-1BFD-4F23-BA84-169CC05FC5A3\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/10685681bafce6febb39770f3387621bf5d67d0b\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/1b562b7f9231432da40d12e19786c1bd7df653a7\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/1e6d9d87626cf89eeffb4d943db12cb5b10bf961\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/35d0137305ae2f97260a9047f445bd4434bd6cc7\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/7d8947f2153ee9c5ab4cb17861a11cc45f30e8c4\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/7fefc294204f10a3405f175f4ac2be16d63f135e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/833e9a1c27b82024db7ff5038a51651f48f05e5e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/e12f6013d0a69660e8b99bfe381b9546ae667328\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.


Loading…