fkie_cve-2025-40119
Vulnerability from fkie_nvd
Published
2025-11-12 11:15
Modified
2025-11-12 16:19
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: ext4: fix potential null deref in ext4_mb_init() In ext4_mb_init(), ext4_mb_avg_fragment_size_destroy() may be called when sbi->s_mb_avg_fragment_size remains uninitialized (e.g., if groupinfo slab cache allocation fails). Since ext4_mb_avg_fragment_size_destroy() lacks null pointer checking, this leads to a null pointer dereference. ================================================================== EXT4-fs: no memory for groupinfo slab cache BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: Oops: 0002 [#1] SMP PTI CPU:2 UID: 0 PID: 87 Comm:mount Not tainted 6.17.0-rc2 #1134 PREEMPT(none) RIP: 0010:_raw_spin_lock_irqsave+0x1b/0x40 Call Trace: <TASK> xa_destroy+0x61/0x130 ext4_mb_init+0x483/0x540 __ext4_fill_super+0x116d/0x17b0 ext4_fill_super+0xd3/0x280 get_tree_bdev_flags+0x132/0x1d0 vfs_get_tree+0x29/0xd0 do_new_mount+0x197/0x300 __x64_sys_mount+0x116/0x150 do_syscall_64+0x50/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e ================================================================== Therefore, add necessary null check to ext4_mb_avg_fragment_size_destroy() to prevent this issue. The same fix is also applied to ext4_mb_largest_free_orders_destroy().
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/00110f3cfc9b34b2dfee2a6c9e55a0ae6df125ae
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3c3fac6bc0a9c00dbe65d8dc0d3a282afe4d3188
Impacted products
Vendor Product Version


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{
  "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-\u003es_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 \u003cTASK\u003e\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()."
    }
  ],
  "id": "CVE-2025-40119",
  "lastModified": "2025-11-12T16:19:12.850",
  "metrics": {},
  "published": "2025-11-12T11:15:41.237",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/00110f3cfc9b34b2dfee2a6c9e55a0ae6df125ae"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3c3fac6bc0a9c00dbe65d8dc0d3a282afe4d3188"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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