CVE-2025-40119

{
  "id": "CVE-2025-40119",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2025-11-12T11:15:41.237",
  "lastModified": "2026-10-19T21:10:00.160",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix potential null deref in ext4_mb_init()\n\nIn ext4_mb_init(), ext4_mb_avg_fragment_size_destroy() may be called\nwhen sbi->s_mb_avg_fragment_size remains uninitialized (e.g., if groupinfo\nslab cache allocation fails). Since ext4_mb_avg_fragment_size_destroy()\nlacks null pointer checking, this leads to a null pointer dereference.\n\n==================================================================\nEXT4-fs: no memory for groupinfo slab cache\nBUG: kernel NULL pointer dereference, address: 0000000000000000\nPGD 0 P4D 0\nOops: Oops: 0002 [#1] SMP PTI\nCPU:2 UID: 0 PID: 87 Comm:mount Not tainted 6.17.0-rc2 #1134 PREEMPT(none)\nRIP: 0010:_raw_spin_lock_irqsave+0x1b/0x40\nCall Trace:\n <TASK>\n xa_destroy+0x61/0x130\n ext4_mb_init+0x483/0x540\n __ext4_fill_super+0x116d/0x17b0\n ext4_fill_super+0xd3/0x280\n get_tree_bdev_flags+0x132/0x1d0\n vfs_get_tree+0x29/0xd0\n do_new_mount+0x197/0x300\n __x64_sys_mount+0x116/0x150\n do_syscall_64+0x50/0x1c0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n==================================================================\n\nTherefore, add necessary null check to ext4_mb_avg_fragment_size_destroy()\nto prevent this issue. The same fix is also applied to\next4_mb_largest_free_orders_destroy()."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\next4: corrección de desreferencia nula potencial en ext4_mb_init()\n\nEn ext4_mb_init(), se puede llamar a ext4_mb_avg_fragment_size_destroy() cuando sbi->s_mb_avg_fragment_size permanece sin inicializar (por ejemplo, si falla la asignación de la caché slab de groupinfo). Dado que ext4_mb_avg_fragment_size_destroy() carece de comprobación de puntero nulo, esto conduce a una desreferencia de puntero nulo.\n\n==================================================================\nEXT4-fs: no hay memoria para la caché slab de groupinfo\nBUG: desreferencia de puntero NULL del kernel, dirección: 0000000000000000\nPGD 0 P4D 0\nOops: Oops: 0002 [#1] SMP PTI\nCPU:2 UID: 0 PID: 87 Comm:mount Not tainted 6.17.0-rc2 #1134 PREEMPT(none)\nRIP: 0010:_raw_spin_lock_irqsave+0x1b/0x40\nCall Trace:\n <TASK>\n xa_destroy+0x61/0x130\n ext4_mb_init+0x483/0x540\n __ext4_fill_super+0x116d/0x17b0\n ext4_fill_super+0xd3/0x280\n get_tree_bdev_flags+0x132/0x1d0\n vfs_get_tree+0x29/0xd0\n do_new_mount+0x197/0x300\n __x64_sys_mount+0x116/0x150\n do_syscall_64+0x50/0x1c0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n==================================================================\n\nPor lo tanto, se añade la comprobación de nulos necesaria a ext4_mb_avg_fragment_size_destroy() para evitar este problema. La misma corrección también se aplica a ext4_mb_largest_free_orders_destroy()."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "fs/ext4/mballoc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "d99d714f714c9492dc64d8ab4329b083dbfa9cab",
              "lessThan": "08d9175578d6a8e9b81921898fbf01aa669cd2be",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "f7eaacbb4e54f8a6c6674c16eff54f703ea63d5e",
              "lessThan": "00110f3cfc9b34b2dfee2a6c9e55a0ae6df125ae",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "f7eaacbb4e54f8a6c6674c16eff54f703ea63d5e",
              "lessThan": "3c3fac6bc0a9c00dbe65d8dc0d3a282afe4d3188",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "fs/ext4/mballoc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.17",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.17",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.17.3",
              "lessThanOrEqual": "6.17.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/00110f3cfc9b34b2dfee2a6c9e55a0ae6df125ae",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/08d9175578d6a8e9b81921898fbf01aa669cd2be",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3c3fac6bc0a9c00dbe65d8dc0d3a282afe4d3188",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}