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CVE-2023-53821

Estado: AplazadaSin puntuar—

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

ip6_vti: fix slab-use-after-free in decode_session6

When ipv6_vti device is set to the qdisc of the sfb type, the cb field of the sent skb may be modified during enqueuing. Then, slab-use-after-free may occur when ipv6_vti device sends IPv6 packets.

As commit f855691975bb ("xfrm6: Fix the nexthdr offset in _decode_session6.") showed, xfrm_decode_session was originally intended only for the receive path. IP6CB(skb)->nhoff is not set during transmission. Therefore, set the cb field in the skb to 0 before sending packets.

Detalles técnicos trazas, registros y código del informe original
The stack information is as follows:
BUG: KASAN: slab-use-after-free in decode_session6+0x103f/0x1890
Read of size 1 at addr ffff88802e08edc2 by task swapper/0/0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.4.0-next-20230707-00001-g84e2cad7f979 #410
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014
Call Trace:
<IRQ>
dump_stack_lvl+0xd9/0x150
print_address_description.constprop.0+0x2c/0x3c0
kasan_report+0x11d/0x130
decode_session6+0x103f/0x1890
__xfrm_decode_session+0x54/0xb0
vti6_tnl_xmit+0x3e6/0x1ee0
dev_hard_start_xmit+0x187/0x700
sch_direct_xmit+0x1a3/0xc30
__qdisc_run+0x510/0x17a0
__dev_queue_xmit+0x2215/0x3b10
neigh_connected_output+0x3c2/0x550
ip6_finish_output2+0x55a/0x1550
ip6_finish_output+0x6b9/0x1270
ip6_output+0x1f1/0x540
ndisc_send_skb+0xa63/0x1890
ndisc_send_rs+0x132/0x6f0
addrconf_rs_timer+0x3f1/0x870
call_timer_fn+0x1a0/0x580
expire_timers+0x29b/0x4b0
run_timer_softirq+0x326/0x910
__do_softirq+0x1d4/0x905
irq_exit_rcu+0xb7/0x120
sysvec_apic_timer_interrupt+0x97/0xc0
</IRQ>
Allocated by task 9176:
kasan_save_stack+0x22/0x40
kasan_set_track+0x25/0x30
__kasan_slab_alloc+0x7f/0x90
kmem_cache_alloc_node+0x1cd/0x410
kmalloc_reserve+0x165/0x270
__alloc_skb+0x129/0x330
netlink_sendmsg+0x9b1/0xe30
sock_sendmsg+0xde/0x190
____sys_sendmsg+0x739/0x920
___sys_sendmsg+0x110/0x1b0
__sys_sendmsg+0xf7/0x1c0
do_syscall_64+0x39/0xb0
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 9176:
kasan_save_stack+0x22/0x40
kasan_set_track+0x25/0x30
kasan_save_free_info+0x2b/0x40
____kasan_slab_free+0x160/0x1c0
slab_free_freelist_hook+0x11b/0x220
kmem_cache_free+0xf0/0x490
skb_free_head+0x17f/0x1b0
skb_release_data+0x59c/0x850
consume_skb+0xd2/0x170
netlink_unicast+0x54f/0x7f0
netlink_sendmsg+0x926/0xe30
sock_sendmsg+0xde/0x190
____sys_sendmsg+0x739/0x920
___sys_sendmsg+0x110/0x1b0
__sys_sendmsg+0xf7/0x1c0
do_syscall_64+0x39/0xb0
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The buggy address belongs to the object at ffff88802e08ed00
which belongs to the cache skbuff_small_head of size 640
The buggy address is located 194 bytes inside of
freed 640-byte region [ffff88802e08ed00, ffff88802e08ef80)

CVSS

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

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).

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-2023-53821",
  "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": "f855691975bb06373a98711e4cfe2c224244b536",
              "lessThan": "0f0ab8d52ee0062b28367dea23c29e254a26d7db",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f855691975bb06373a98711e4cfe2c224244b536",
              "lessThan": "fa6c6c04f6c9b21b315023f487e5a07ae7fcf647",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f855691975bb06373a98711e4cfe2c224244b536",
              "lessThan": "eb47e612e59c358c3968a92f90dd36c78c9a2106",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f855691975bb06373a98711e4cfe2c224244b536",
              "lessThan": "ec23b25e5687dbd644c0f57bcb6af22dd5a6dd36",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f855691975bb06373a98711e4cfe2c224244b536",
              "lessThan": "a1639a82ce14af76b6419778d343ccbff86ee626",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f855691975bb06373a98711e4cfe2c224244b536",
              "lessThan": "55ad2309205cc00c585344374c7472420e1b2c12",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f855691975bb06373a98711e4cfe2c224244b536",
              "lessThan": "c070688bfbe7759e61e697e421b2a331b0dd74bc",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f855691975bb06373a98711e4cfe2c224244b536",
              "lessThan": "9fd41f1ba638938c9a1195d09bc6fa3be2712f25",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "net/ipv6/ip6_vti.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.19"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "3.19",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "4.14.324",
              "versionType": "semver",
              "lessThanOrEqual": "4.14.*"
            },
            {
              "status": "unaffected",
              "version": "4.19.293",
              "versionType": "semver",
              "lessThanOrEqual": "4.19.*"
            },
            {
              "status": "unaffected",
              "version": "5.4.255",
              "versionType": "semver",
              "lessThanOrEqual": "5.4.*"
            },
            {
              "status": "unaffected",
              "version": "5.10.192",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "status": "unaffected",
              "version": "5.15.128",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.47",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.4.12",
              "versionType": "semver",
              "lessThanOrEqual": "6.4.*"
            },
            {
              "status": "unaffected",
              "version": "6.5",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "net/ipv6/ip6_vti.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-12-09T16:17:20.877",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0f0ab8d52ee0062b28367dea23c29e254a26d7db",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/55ad2309205cc00c585344374c7472420e1b2c12",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9fd41f1ba638938c9a1195d09bc6fa3be2712f25",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a1639a82ce14af76b6419778d343ccbff86ee626",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c070688bfbe7759e61e697e421b2a331b0dd74bc",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/eb47e612e59c358c3968a92f90dd36c78c9a2106",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ec23b25e5687dbd644c0f57bcb6af22dd5a6dd36",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/fa6c6c04f6c9b21b315023f487e5a07ae7fcf647",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Deferred",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6_vti: fix slab-use-after-free in decode_session6\n\nWhen ipv6_vti device is set to the qdisc of the sfb type, the cb field\nof the sent skb may be modified during enqueuing. Then,\nslab-use-after-free may occur when ipv6_vti device sends IPv6 packets.\n\nThe stack information is as follows:\nBUG: KASAN: slab-use-after-free in decode_session6+0x103f/0x1890\nRead of size 1 at addr ffff88802e08edc2 by task swapper/0/0\nCPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.4.0-next-20230707-00001-g84e2cad7f979 #410\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014\nCall Trace:\n<IRQ>\ndump_stack_lvl+0xd9/0x150\nprint_address_description.constprop.0+0x2c/0x3c0\nkasan_report+0x11d/0x130\ndecode_session6+0x103f/0x1890\n__xfrm_decode_session+0x54/0xb0\nvti6_tnl_xmit+0x3e6/0x1ee0\ndev_hard_start_xmit+0x187/0x700\nsch_direct_xmit+0x1a3/0xc30\n__qdisc_run+0x510/0x17a0\n__dev_queue_xmit+0x2215/0x3b10\nneigh_connected_output+0x3c2/0x550\nip6_finish_output2+0x55a/0x1550\nip6_finish_output+0x6b9/0x1270\nip6_output+0x1f1/0x540\nndisc_send_skb+0xa63/0x1890\nndisc_send_rs+0x132/0x6f0\naddrconf_rs_timer+0x3f1/0x870\ncall_timer_fn+0x1a0/0x580\nexpire_timers+0x29b/0x4b0\nrun_timer_softirq+0x326/0x910\n__do_softirq+0x1d4/0x905\nirq_exit_rcu+0xb7/0x120\nsysvec_apic_timer_interrupt+0x97/0xc0\n</IRQ>\nAllocated by task 9176:\nkasan_save_stack+0x22/0x40\nkasan_set_track+0x25/0x30\n__kasan_slab_alloc+0x7f/0x90\nkmem_cache_alloc_node+0x1cd/0x410\nkmalloc_reserve+0x165/0x270\n__alloc_skb+0x129/0x330\nnetlink_sendmsg+0x9b1/0xe30\nsock_sendmsg+0xde/0x190\n____sys_sendmsg+0x739/0x920\n___sys_sendmsg+0x110/0x1b0\n__sys_sendmsg+0xf7/0x1c0\ndo_syscall_64+0x39/0xb0\nentry_SYSCALL_64_after_hwframe+0x63/0xcd\nFreed by task 9176:\nkasan_save_stack+0x22/0x40\nkasan_set_track+0x25/0x30\nkasan_save_free_info+0x2b/0x40\n____kasan_slab_free+0x160/0x1c0\nslab_free_freelist_hook+0x11b/0x220\nkmem_cache_free+0xf0/0x490\nskb_free_head+0x17f/0x1b0\nskb_release_data+0x59c/0x850\nconsume_skb+0xd2/0x170\nnetlink_unicast+0x54f/0x7f0\nnetlink_sendmsg+0x926/0xe30\nsock_sendmsg+0xde/0x190\n____sys_sendmsg+0x739/0x920\n___sys_sendmsg+0x110/0x1b0\n__sys_sendmsg+0xf7/0x1c0\ndo_syscall_64+0x39/0xb0\nentry_SYSCALL_64_after_hwframe+0x63/0xcd\nThe buggy address belongs to the object at ffff88802e08ed00\nwhich belongs to the cache skbuff_small_head of size 640\nThe buggy address is located 194 bytes inside of\nfreed 640-byte region [ffff88802e08ed00, ffff88802e08ef80)\n\nAs commit f855691975bb (\"xfrm6: Fix the nexthdr offset in\n_decode_session6.\") showed, xfrm_decode_session was originally intended\nonly for the receive path. IP6CB(skb)->nhoff is not set during\ntransmission. Therefore, set the cb field in the skb to 0 before\nsending packets."
    }
  ],
  "lastModified": "2026-06-17T06:46:07.850",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}