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CVE-2023-53752

Estado: AplazadaAlta (7.8)—

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

net: deal with integer overflows in kmalloc_reserve()

This allowed various crash as reported by syzbot [1] and Kyle Zeng.

Problem is that if @size is bigger than 0x80000001, kmalloc_size_roundup(size) returns 2^32.

kmalloc_reserve() uses a 32bit variable (obj_size), so 2^32 is truncated to 0.

kmalloc(0) returns ZERO_SIZE_PTR which is not handled by skb allocations.

Following trace can be triggered if a netdev->mtu is set close to 0x7fffffff

We might in the future limit netdev->mtu to more sensible limit (like KMALLOC_MAX_SIZE).

This patch is based on a syzbot report, and also a report and tentative fix from Kyle Zeng.

Detalles técnicos trazas, registros y código del informe original
Blamed commit changed:
    ptr = kmalloc(size);
    if (ptr)
      size = ksize(ptr);

    size = kmalloc_size_roundup(size);
    ptr = kmalloc(size);

[1]
BUG: KASAN: user-memory-access in __build_skb_around net/core/skbuff.c:294 [inline]
BUG: KASAN: user-memory-access in __alloc_skb+0x3c4/0x6e8 net/core/skbuff.c:527
Write of size 32 at addr 00000000fffffd10 by task syz-executor.4/22554

CPU: 1 PID: 22554 Comm: syz-executor.4 Not tainted 6.1.39-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
Call trace:
dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:279
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:286
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x120/0x1a0 lib/dump_stack.c:106
print_report+0xe4/0x4b4 mm/kasan/report.c:398
kasan_report+0x150/0x1ac mm/kasan/report.c:495
kasan_check_range+0x264/0x2a4 mm/kasan/generic.c:189
memset+0x40/0x70 mm/kasan/shadow.c:44
__build_skb_around net/core/skbuff.c:294 [inline]
__alloc_skb+0x3c4/0x6e8 net/core/skbuff.c:527
alloc_skb include/linux/skbuff.h:1316 [inline]
igmpv3_newpack+0x104/0x1088 net/ipv4/igmp.c:359
add_grec+0x81c/0x1124 net/ipv4/igmp.c:534
igmpv3_send_cr net/ipv4/igmp.c:667 [inline]
igmp_ifc_timer_expire+0x1b0/0x1008 net/ipv4/igmp.c:810
call_timer_fn+0x1c0/0x9f0 kernel/time/timer.c:1474
expire_timers kernel/time/timer.c:1519 [inline]
__run_timers+0x54c/0x710 kernel/time/timer.c:1790
run_timer_softirq+0x28/0x4c kernel/time/timer.c:1803
_stext+0x380/0xfbc
____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:79
call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:891
do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:84
invoke_softirq kernel/softirq.c:437 [inline]
__irq_exit_rcu+0x1c0/0x4cc kernel/softirq.c:683
irq_exit_rcu+0x14/0x78 kernel/softirq.c:695
el0_interrupt+0x7c/0x2e0 arch/arm64/kernel/entry-common.c:717
__el0_irq_handler_common+0x18/0x24 arch/arm64/kernel/entry-common.c:724
el0t_64_irq_handler+0x10/0x1c arch/arm64/kernel/entry-common.c:729
el0t_64_irq+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

CVSS

Probabilidad de explotación (EPSS)

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).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Vulnerabilidad de desbordamiento de enteros en kmalloc_reserve() del kernel Linux que, al acceder localmente con privilegios limitados, causa un crash (DoS) mediante manipulación de MTU. Requiere acceso local (AV:L/PR:L) sin interacción, mapea a T1068.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Threat Intelligence ProgramFilter Network TrafficExecution PreventionApplication Isolation and SandboxingExploit ProtectionUpdate Software

Tecnologías afectadas (1)

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

Linux — Linux KernelAI

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2023-53752",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.8,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "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": "0dbc898f5917c5a3bec6be19d9f5469cbc351a7d",
              "lessThan": "31cf7853a940181593e4472fc56f46574123f9f6",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "12d6c1d3a2ad0c199ec57c201cdc71e8e157a232",
              "lessThan": "e4ffc47a1c3e5d11a853aa178c9a5136e79412e9",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "12d6c1d3a2ad0c199ec57c201cdc71e8e157a232",
              "lessThan": "bf7da02d2b8faf324206e1cbe64a4813ff903cc1",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "12d6c1d3a2ad0c199ec57c201cdc71e8e157a232",
              "lessThan": "915d975b2ffa58a14bfcf16fafe00c41315949ff",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6.1.31",
              "lessThan": "6.1.54",
              "versionType": "semver"
            }
          ],
          "programFiles": [
            "net/core/skbuff.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.2"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.2",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.1.54",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.4.16",
              "versionType": "semver",
              "lessThanOrEqual": "6.4.*"
            },
            {
              "status": "unaffected",
              "version": "6.5.3",
              "versionType": "semver",
              "lessThanOrEqual": "6.5.*"
            },
            {
              "status": "unaffected",
              "version": "6.6",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "net/core/skbuff.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-12-08T02:15:50.713",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/31cf7853a940181593e4472fc56f46574123f9f6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/915d975b2ffa58a14bfcf16fafe00c41315949ff",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/bf7da02d2b8faf324206e1cbe64a4813ff903cc1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e4ffc47a1c3e5d11a853aa178c9a5136e79412e9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Deferred",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: deal with integer overflows in kmalloc_reserve()\n\nBlamed commit changed:\n    ptr = kmalloc(size);\n    if (ptr)\n      size = ksize(ptr);\n\n    size = kmalloc_size_roundup(size);\n    ptr = kmalloc(size);\n\nThis allowed various crash as reported by syzbot [1]\nand Kyle Zeng.\n\nProblem is that if @size is bigger than 0x80000001,\nkmalloc_size_roundup(size) returns 2^32.\n\nkmalloc_reserve() uses a 32bit variable (obj_size),\nso 2^32 is truncated to 0.\n\nkmalloc(0) returns ZERO_SIZE_PTR which is not handled by\nskb allocations.\n\nFollowing trace can be triggered if a netdev->mtu is set\nclose to 0x7fffffff\n\nWe might in the future limit netdev->mtu to more sensible\nlimit (like KMALLOC_MAX_SIZE).\n\nThis patch is based on a syzbot report, and also a report\nand tentative fix from Kyle Zeng.\n\n[1]\nBUG: KASAN: user-memory-access in __build_skb_around net/core/skbuff.c:294 [inline]\nBUG: KASAN: user-memory-access in __alloc_skb+0x3c4/0x6e8 net/core/skbuff.c:527\nWrite of size 32 at addr 00000000fffffd10 by task syz-executor.4/22554\n\nCPU: 1 PID: 22554 Comm: syz-executor.4 Not tainted 6.1.39-syzkaller #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023\nCall trace:\ndump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:279\nshow_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:286\n__dump_stack lib/dump_stack.c:88 [inline]\ndump_stack_lvl+0x120/0x1a0 lib/dump_stack.c:106\nprint_report+0xe4/0x4b4 mm/kasan/report.c:398\nkasan_report+0x150/0x1ac mm/kasan/report.c:495\nkasan_check_range+0x264/0x2a4 mm/kasan/generic.c:189\nmemset+0x40/0x70 mm/kasan/shadow.c:44\n__build_skb_around net/core/skbuff.c:294 [inline]\n__alloc_skb+0x3c4/0x6e8 net/core/skbuff.c:527\nalloc_skb include/linux/skbuff.h:1316 [inline]\nigmpv3_newpack+0x104/0x1088 net/ipv4/igmp.c:359\nadd_grec+0x81c/0x1124 net/ipv4/igmp.c:534\nigmpv3_send_cr net/ipv4/igmp.c:667 [inline]\nigmp_ifc_timer_expire+0x1b0/0x1008 net/ipv4/igmp.c:810\ncall_timer_fn+0x1c0/0x9f0 kernel/time/timer.c:1474\nexpire_timers kernel/time/timer.c:1519 [inline]\n__run_timers+0x54c/0x710 kernel/time/timer.c:1790\nrun_timer_softirq+0x28/0x4c kernel/time/timer.c:1803\n_stext+0x380/0xfbc\n____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:79\ncall_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:891\ndo_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:84\ninvoke_softirq kernel/softirq.c:437 [inline]\n__irq_exit_rcu+0x1c0/0x4cc kernel/softirq.c:683\nirq_exit_rcu+0x14/0x78 kernel/softirq.c:695\nel0_interrupt+0x7c/0x2e0 arch/arm64/kernel/entry-common.c:717\n__el0_irq_handler_common+0x18/0x24 arch/arm64/kernel/entry-common.c:724\nel0t_64_irq_handler+0x10/0x1c arch/arm64/kernel/entry-common.c:729\nel0t_64_irq+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584"
    }
  ],
  "lastModified": "2026-08-04T10:19:19.940",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}