CVE-2023-54251

Estado: AplazadaSin puntuar—

In the Linux kernel, the following vulnerability has been resolved:

net/sched: taprio: Limit TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME to INT_MAX.

syzkaller found zero division error [0] in div_s64_rem() called from get_cycle_time_elapsed(), where sched->cycle_time is the divisor.

We have tests in parse_taprio_schedule() so that cycle_time will never be 0, and actually cycle_time is not 0 in get_cycle_time_elapsed().

The problem is that the types of divisor are different; cycle_time is s64, but the argument of div_s64_rem() is s32.

syzkaller fed this input and 0x100000000 is cast to s32 to be 0.

We use s64 for cycle_time to cast it to ktime_t, so let's keep it and set max for cycle_time.

Leer descripción completaMostrar menos

While at it, we prevent overflow in setup_txtime() and add another test in parse_taprio_schedule() to check if cycle_time overflows.

Also, we add a new tdc test case for this issue.

Detalles técnicos trazas, registros y código del informe original

  @TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME={0xc, 0x8, 0x100000000}

[0]:
divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 1 PID: 103 Comm: kworker/1:3 Not tainted 6.5.0-rc1-00330-g60cc1f7d0605 #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:div_s64_rem include/linux/math64.h:42 [inline]
RIP: 0010:get_cycle_time_elapsed net/sched/sch_taprio.c:223 [inline]
RIP: 0010:find_entry_to_transmit+0x252/0x7e0 net/sched/sch_taprio.c:344
Code: 3c 02 00 0f 85 5e 05 00 00 48 8b 4c 24 08 4d 8b bd 40 01 00 00 48 8b 7c 24 48 48 89 c8 4c 29 f8 48 63 f7 48 99 48 89 74 24 70 <48> f7 fe 48 29 d1 48 8d 04 0f 49 89 cc 48 89 44 24 20 49 8d 85 10
RSP: 0018:ffffc90000acf260 EFLAGS: 00010206
RAX: 177450e0347560cf RBX: 0000000000000000 RCX: 177450e0347560cf
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000100000000
RBP: 0000000000000056 R08: 0000000000000000 R09: ffffed10020a0934
R10: ffff8880105049a7 R11: ffff88806cf3a520 R12: ffff888010504800
R13: ffff88800c00d800 R14: ffff8880105049a0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0edf84f0e8 CR3: 000000000d73c002 CR4: 0000000000770ee0
PKRU: 55555554
Call Trace:
 <TASK>
 get_packet_txtime net/sched/sch_taprio.c:508 [inline]
 taprio_enqueue_one+0x900/0xff0 net/sched/sch_taprio.c:577
 taprio_enqueue+0x378/0xae0 net/sched/sch_taprio.c:658
 dev_qdisc_enqueue+0x46/0x170 net/core/dev.c:3732
 __dev_xmit_skb net/core/dev.c:3821 [inline]
 __dev_queue_xmit+0x1b2f/0x3000 net/core/dev.c:4169
 dev_queue_xmit include/linux/netdevice.h:3088 [inline]
 neigh_resolve_output net/core/neighbour.c:1552 [inline]
 neigh_resolve_output+0x4a7/0x780 net/core/neighbour.c:1532
 neigh_output include/net/neighbour.h:544 [inline]
 ip6_finish_output2+0x924/0x17d0 net/ipv6/ip6_output.c:135
 __ip6_finish_output+0x620/0xaa0 net/ipv6/ip6_output.c:196
 ip6_finish_output net/ipv6/ip6_output.c:207 [inline]
 NF_HOOK_COND include/linux/netfilter.h:292 [inline]
 ip6_output+0x206/0x410 net/ipv6/ip6_output.c:228
 dst_output include/net/dst.h:458 [inline]
 NF_HOOK.constprop.0+0xea/0x260 include/linux/netfilter.h:303
 ndisc_send_skb+0x872/0xe80 net/ipv6/ndisc.c:508
 ndisc_send_ns+0xb5/0x130 net/ipv6/ndisc.c:666
 addrconf_dad_work+0xc14/0x13f0 net/ipv6/addrconf.c:4175
 process_one_work+0x92c/0x13a0 kernel/workqueue.c:2597
 worker_thread+0x60f/0x1240 kernel/workqueue.c:2748
 kthread+0x2fe/0x3f0 kernel/kthread.c:389
 ret_from_fork+0x2c/0x50 arch/x86/entry/entry_64.S:308
 </TASK>
Modules linked in:

CVSS

NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.20%
Percentil entre todas las CVEs puntuadas: 9
Fecha de la puntuación: 6/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Linux — Linux Kernel^AI

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2023-54251",
  "cveTags": [],
  "metrics": {},
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4cfd5779bd6efe8c76b4494aec63a063be0d2ff2",
              "lessThan": "f04f6d9b3b060f7e11219a65a76da65f1489e391",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "4cfd5779bd6efe8c76b4494aec63a063be0d2ff2",
              "lessThan": "0b45af982a4df0b14fb8669ee2a871cfdfa6a39c",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "4cfd5779bd6efe8c76b4494aec63a063be0d2ff2",
              "lessThan": "57b3fe08ae06ef11af007b4a182629b12a961e30",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "4cfd5779bd6efe8c76b4494aec63a063be0d2ff2",
              "lessThan": "e739718444f7bf2fa3d70d101761ad83056ca628",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "net/sched/sch_taprio.c",
            "tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.3"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.3",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.15.126",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.45",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.4.10",
              "versionType": "semver",
              "lessThanOrEqual": "6.4.*"
            },
            {
              "status": "unaffected",
              "version": "6.5",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "net/sched/sch_taprio.c",
            "tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-12-30T13:16:13.763",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0b45af982a4df0b14fb8669ee2a871cfdfa6a39c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/57b3fe08ae06ef11af007b4a182629b12a961e30",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e739718444f7bf2fa3d70d101761ad83056ca628",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f04f6d9b3b060f7e11219a65a76da65f1489e391",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Deferred",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: taprio: Limit TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME to INT_MAX.\n\nsyzkaller found zero division error [0] in div_s64_rem() called from\nget_cycle_time_elapsed(), where sched->cycle_time is the divisor.\n\nWe have tests in parse_taprio_schedule() so that cycle_time will never\nbe 0, and actually cycle_time is not 0 in get_cycle_time_elapsed().\n\nThe problem is that the types of divisor are different; cycle_time is\ns64, but the argument of div_s64_rem() is s32.\n\nsyzkaller fed this input and 0x100000000 is cast to s32 to be 0.\n\n  @TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME={0xc, 0x8, 0x100000000}\n\nWe use s64 for cycle_time to cast it to ktime_t, so let's keep it and\nset max for cycle_time.\n\nWhile at it, we prevent overflow in setup_txtime() and add another\ntest in parse_taprio_schedule() to check if cycle_time overflows.\n\nAlso, we add a new tdc test case for this issue.\n\n[0]:\ndivide error: 0000 [#1] PREEMPT SMP KASAN NOPTI\nCPU: 1 PID: 103 Comm: kworker/1:3 Not tainted 6.5.0-rc1-00330-g60cc1f7d0605 #3\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014\nWorkqueue: ipv6_addrconf addrconf_dad_work\nRIP: 0010:div_s64_rem include/linux/math64.h:42 [inline]\nRIP: 0010:get_cycle_time_elapsed net/sched/sch_taprio.c:223 [inline]\nRIP: 0010:find_entry_to_transmit+0x252/0x7e0 net/sched/sch_taprio.c:344\nCode: 3c 02 00 0f 85 5e 05 00 00 48 8b 4c 24 08 4d 8b bd 40 01 00 00 48 8b 7c 24 48 48 89 c8 4c 29 f8 48 63 f7 48 99 48 89 74 24 70 <48> f7 fe 48 29 d1 48 8d 04 0f 49 89 cc 48 89 44 24 20 49 8d 85 10\nRSP: 0018:ffffc90000acf260 EFLAGS: 00010206\nRAX: 177450e0347560cf RBX: 0000000000000000 RCX: 177450e0347560cf\nRDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000100000000\nRBP: 0000000000000056 R08: 0000000000000000 R09: ffffed10020a0934\nR10: ffff8880105049a7 R11: ffff88806cf3a520 R12: ffff888010504800\nR13: ffff88800c00d800 R14: ffff8880105049a0 R15: 0000000000000000\nFS:  0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f0edf84f0e8 CR3: 000000000d73c002 CR4: 0000000000770ee0\nPKRU: 55555554\nCall Trace:\n <TASK>\n get_packet_txtime net/sched/sch_taprio.c:508 [inline]\n taprio_enqueue_one+0x900/0xff0 net/sched/sch_taprio.c:577\n taprio_enqueue+0x378/0xae0 net/sched/sch_taprio.c:658\n dev_qdisc_enqueue+0x46/0x170 net/core/dev.c:3732\n __dev_xmit_skb net/core/dev.c:3821 [inline]\n __dev_queue_xmit+0x1b2f/0x3000 net/core/dev.c:4169\n dev_queue_xmit include/linux/netdevice.h:3088 [inline]\n neigh_resolve_output net/core/neighbour.c:1552 [inline]\n neigh_resolve_output+0x4a7/0x780 net/core/neighbour.c:1532\n neigh_output include/net/neighbour.h:544 [inline]\n ip6_finish_output2+0x924/0x17d0 net/ipv6/ip6_output.c:135\n __ip6_finish_output+0x620/0xaa0 net/ipv6/ip6_output.c:196\n ip6_finish_output net/ipv6/ip6_output.c:207 [inline]\n NF_HOOK_COND include/linux/netfilter.h:292 [inline]\n ip6_output+0x206/0x410 net/ipv6/ip6_output.c:228\n dst_output include/net/dst.h:458 [inline]\n NF_HOOK.constprop.0+0xea/0x260 include/linux/netfilter.h:303\n ndisc_send_skb+0x872/0xe80 net/ipv6/ndisc.c:508\n ndisc_send_ns+0xb5/0x130 net/ipv6/ndisc.c:666\n addrconf_dad_work+0xc14/0x13f0 net/ipv6/addrconf.c:4175\n process_one_work+0x92c/0x13a0 kernel/workqueue.c:2597\n worker_thread+0x60f/0x1240 kernel/workqueue.c:2748\n kthread+0x2fe/0x3f0 kernel/kthread.c:389\n ret_from_fork+0x2c/0x50 arch/x86/entry/entry_64.S:308\n </TASK>\nModules linked in:"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet/sched: taprio: Limitar TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME a INT_MAX.\n\nsyzkaller encontró un error de división por cero [0] en div_s64_rem() llamada desde get_cycle_time_elapsed(), donde sched-&gt;cycle_time es el divisor.\n\nTenemos pruebas en parse_taprio_schedule() para que cycle_time nunca sea 0, y de hecho cycle_time no es 0 en get_cycle_time_elapsed().\n\nEl problema es que los tipos de divisor son diferentes; cycle_time es s64, pero el argumento de div_s64_rem() es s32.\n\nsyzkaller alimentó esta entrada y 0x100000000 se convierte a s32 para ser 0.\n\n  @TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME={0xc, 0x8, 0x100000000}\n\nUsamos s64 para cycle_time para convertirlo a ktime_t, así que mantengámoslo y establezcamos el máximo para cycle_time.\n\nYa que estamos, prevenimos el desbordamiento en setup_txtime() y añadimos otra prueba en parse_taprio_schedule() para verificar si cycle_time se desborda.\n\nAdemás, añadimos un nuevo caso de prueba tdc para este problema.\n\n[0]:\ndivide error: 0000 [#1] PREEMPT SMP KASAN NOPTI\nCPU: 1 PID: 103 Comm: kworker/1:3 Not tainted 6.5.0-rc1-00330-g60cc1f7d0605 #3\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014\nWorkqueue: ipv6_addrconf addrconf_dad_work\nRIP: 0010:div_s64_rem include/linux/math64.h:42 [inline]\nRIP: 0010:get_cycle_time_elapsed net/sched/sch_taprio.c:223 [inline]\nRIP: 0010:find_entry_to_transmit+0x252/0x7e0 net/sched/sch_taprio.c:344\nCode: 3c 02 00 0f 85 5e 05 00 00 48 8b 4c 24 08 4d 8b bd 40 01 00 00 48 8b 7c 24 48 48 89 c8 4c 29 f8 48 63 f7 48 99 48 89 74 24 70 &lt;48&gt; f7 fe 48 29 d1 48 8d 04 0f 49 89 cc 48 89 44 24 20 49 8d 85 10\nRSP: 0018:ffffc90000acf260 EFLAGS: 00010206\nRAX: 177450e0347560cf RBX: 0000000000000000 RCX: 177450e0347560cf\nRDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000100000000\nRBP: 0000000000000056 R08: 0000000000000000 R09: ffffed10020a0934\nR10: ffff8880105049a7 R11: ffff88806cf3a520 R12: ffff888010504800\nR13: ffff88800c00d800 R14: ffff8880105049a0 R15: 0000000000000000\nFS:  0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f0edf84f0e8 CR3: 000000000d73c002 CR4: 0000000000770ee0\nPKRU: 55555554\nCall Trace:\n \n get_packet_txtime net/sched/sch_taprio.c:508 [inline]\n taprio_enqueue_one+0x900/0xff0 net/sched/sch_taprio.c:577\n taprio_enqueue+0x378/0xae0 net/sched/sch_taprio.c:658\n dev_qdisc_enqueue+0x46/0x170 net/core/dev.c:3732\n __dev_xmit_skb net/core/dev.c:3821 [inline]\n __dev_queue_xmit+0x1b2f/0x3000 net/core/dev.c:4169\n dev_queue_xmit include/linux/netdevice.h:3088 [inline]\n neigh_resolve_output net/core/neighbour.c:1552 [inline]\n neigh_resolve_output+0x4a7/0x780 net/core/neighbour.c:1532\n neigh_output include/net/neighbour.h:544 [inline]\n ip6_finish_output2+0x924/0x17d0 net/ipv6/ip6_output.c:135\n __ip6_finish_output+0x620/0xaa0 net/ipv6/ip6_output.c:196\n ip6_finish_output net/ipv6/ip6_output.c:207 [inline]\n NF_HOOK_COND include/linux/netfilter.h:292 [inline]\n ip6_output+0x206/0x410 net/ipv6/ip6_output.c:228\n dst_output include/net/dst.h:458 [inline]\n NF_HOOK.constprop.0+0xea/0x260 include/linux/netfilter.h:303\n ndisc_send_skb+0x872/0xe80 net/ipv6/ndisc.c:508\n ndisc_send_ns+0xb5/0x130 net/ipv6/ndisc.c:666\n addrconf_dad_work+0xc14/0x13f0 net/ipv6/addrconf.c:4175\n process_one_work+0x92c/0x13a0 kernel/workqueue.c:2597\n worker_thread+0x60f/0x1240 kernel/workqueue.c:2748\n kthread+0x2fe/0x3f0 kernel/kthread.c:389\n ret_from_fork+0x2c/0x50 arch/x86/entry/entry_64.S:308\n \nModules linked in:"
    }
  ],
  "lastModified": "2026-06-17T06:47:05.797",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}