CVE-2026-72354
In the Linux kernel, the following vulnerability has been resolved:
ntfs: avoid stale runlist element dereference in MFT writeback
ntfs_write_mft_block() maps each $MFT record through the $MFT data runlist. For sub-folio clusters it looks up a struct runlist_element under ni->runlist.lock, drops the lock, and later uses rl->length and rl->vcn when choosing folio_sz.
That pointer is only borrowed from ni->runlist.rl. Concurrent $MFT allocation extension can merge a replacement runlist under the same lock, and ntfs_rl_realloc() can free the old backing array. If that happens between the lookup and the later folio_sz decision, writeback can dereference freed runlist storage.
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The buggy scenario involves two paths, with each column showing the order within that path:
MFT writeback path: $MFT allocation extension: 1. Look up rl under 1. Extend the $MFT data allocation. ni->runlist.lock. 2. Publish a replacement runlist. 2. Drop ni->runlist.lock. 3. Free the old runlist array. 3. Read rl->length and rl->vcn to choose folio_sz.
Compute the remaining run length while ni->runlist.lock is still held, and use that scalar after unlock. This preserves the existing folio sizing decision without carrying a borrowed runlist_element across the lock boundary.
Detalles técnicos trazas, registros y código del informe original
Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in ntfs_mft_writepages+0x1c8d/0x1fb0 Call Trace: <TASK> dump_stack_lvl+0x66/0xa0 print_report+0xce/0x630 ? ntfs_mft_writepages+0x1c8d/0x1fb0 ? srso_alias_return_thunk+0x5/0xfbef5 ? __virt_addr_valid+0x20d/0x410 ? ntfs_mft_writepages+0x1c8d/0x1fb0 kasan_report+0xe0/0x110 ? ntfs_mft_writepages+0x1c8d/0x1fb0 ntfs_mft_writepages+0x1c8d/0x1fb0 ? __pfx_ntfs_mft_writepages+0x10/0x10 ? __pfx___mutex_unlock_slowpath+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? iput+0x92/0xa80 do_writepages+0x219/0x530 ? __pfx_do_writepages+0x10/0x10 __writeback_single_inode+0x117/0xf50 ? do_raw_spin_lock+0x130/0x270 ? __pfx_do_raw_spin_lock+0x10/0x10 ? __pfx___writeback_single_inode+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 writeback_sb_inodes+0x65b/0x1810 ? srso_alias_return_thunk+0x5/0xfbef5 ? lock_acquire+0x2b8/0x2f0 ? __pfx_writeback_sb_inodes+0x10/0x10 ? lock_release+0x1e0/0x280 ? _raw_spin_unlock+0x23/0x40 ? move_expired_inodes+0x2b8/0x850 __writeback_inodes_wb+0xf4/0x270 ? __pfx___writeback_inodes_wb+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? queue_io+0x2e4/0x410 wb_writeback+0x666/0x880 ? srso_alias_return_thunk+0x5/0xfbef5 ? __pfx_wb_writeback+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? get_nr_dirty_inodes+0x1c/0x170 wb_workfn+0x75e/0xbb0 ? srso_alias_return_thunk+0x5/0xfbef5 ? _raw_spin_unlock_irqrestore+0x27/0x60 ? __pfx_wb_workfn+0x10/0x10 ? __pfx_debug_object_deactivate+0x10/0x10 ? lock_acquire+0x2b8/0x2f0 ? srso_alias_return_thunk+0x5/0xfbef5 ? lock_release+0x1e0/0x280 process_one_work+0x8d0/0x1870 ? __pfx_process_one_work+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 worker_thread+0x575/0xf80 ? __pfx_worker_thread+0x10/0x10 kthread+0x2e7/0x3c0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x576/0x810 ? __pfx_ret_from_fork+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? __switch_to+0x57e/0xe10 ? __switch_to_asm+0x33/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 970: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 __kasan_kmalloc+0xaa/0xb0 __kvmalloc_node_noprof+0x353/0x920 ntfs_rl_realloc+0x3c/0x80 ntfs_runlists_merge+0x1212/0x3010 ntfs_mft_data_extend_allocation_nolock+0x3e0/0x1f40 ntfs_mft_record_alloc+0x1ab4/0x4f10 __ntfs_create+0x680/0x2e50 ntfs_create+0x1e6/0x3a0 path_openat+0x2b55/0x3c10 do_file_open+0x1f4/0x460 do_sys_openat2+0xde/0x170 __x64_sys_openat+0x122/0x1e0 do_syscall_64+0x115/0x6a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 1294: kasan_save_ ---truncated---
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 8.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.51%
- Percentil entre todas las CVEs puntuadas: 41
- 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).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1210Exploitation of Remote Serviceslateral movement25 % - Impacto principal
T1499.004Application or System Exploitationimpact45 % - Impacto secundario
T1561.001Disk Content Wipeimpact35 %
Vulnerabilidad de kernel NTFS con use-after-free que requiere PR:L (acceso local autenticado). El impacto principal es denegación de servicio (BUG: KASAN en writepages); secundariamente, corrupción de datos del MFT durante writeback.
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
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
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{
"id": "CVE-2026-72354",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 8.8,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/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": 2.8
}
]
},
"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": "115380f9a2f9675c7924563cbba70d40cae8fb81",
"lessThan": "9a2e36963a3fc52401586657d34e3f1c5a01ea56",
"versionType": "git"
},
{
"status": "affected",
"version": "115380f9a2f9675c7924563cbba70d40cae8fb81",
"lessThan": "81fe702ff1760da32bcd3ef4494b2a33dbeced72",
"versionType": "git"
}
],
"programFiles": [
"fs/ntfs/mft.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "7.1"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "7.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/ntfs/mft.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-08-15T06:22:08.840",
"references": [
{
"url": "https://git.kernel.org/stable/c/81fe702ff1760da32bcd3ef4494b2a33dbeced72",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/9a2e36963a3fc52401586657d34e3f1c5a01ea56",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: avoid stale runlist element dereference in MFT writeback\n\nntfs_write_mft_block() maps each $MFT record through the $MFT data\nrunlist. For sub-folio clusters it looks up a struct runlist_element under\nni->runlist.lock, drops the lock, and later uses rl->length and rl->vcn\nwhen choosing folio_sz.\n\nThat pointer is only borrowed from ni->runlist.rl. Concurrent $MFT\nallocation extension can merge a replacement runlist under the same lock,\nand ntfs_rl_realloc() can free the old backing array. If that happens\nbetween the lookup and the later folio_sz decision, writeback can\ndereference freed runlist storage.\n\nThe buggy scenario involves two paths, with each column showing the order\nwithin that path:\n\nMFT writeback path: $MFT allocation extension:\n1. Look up rl under 1. Extend the $MFT data allocation.\n ni->runlist.lock. 2. Publish a replacement runlist.\n2. Drop ni->runlist.lock. 3. Free the old runlist array.\n3. Read rl->length and rl->vcn\n to choose folio_sz.\n\nCompute the remaining run length while ni->runlist.lock is still held, and\nuse that scalar after unlock. This preserves the existing folio sizing\ndecision without carrying a borrowed runlist_element across the lock\nboundary.\n\nValidation reproduced this kernel report:\nBUG: KASAN: slab-use-after-free in ntfs_mft_writepages+0x1c8d/0x1fb0\n\nCall Trace:\n <TASK>\n dump_stack_lvl+0x66/0xa0\n print_report+0xce/0x630\n ? ntfs_mft_writepages+0x1c8d/0x1fb0\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? __virt_addr_valid+0x20d/0x410\n ? ntfs_mft_writepages+0x1c8d/0x1fb0\n kasan_report+0xe0/0x110\n ? ntfs_mft_writepages+0x1c8d/0x1fb0\n ntfs_mft_writepages+0x1c8d/0x1fb0\n ? __pfx_ntfs_mft_writepages+0x10/0x10\n ? __pfx___mutex_unlock_slowpath+0x10/0x10\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? iput+0x92/0xa80\n do_writepages+0x219/0x530\n ? __pfx_do_writepages+0x10/0x10\n __writeback_single_inode+0x117/0xf50\n ? do_raw_spin_lock+0x130/0x270\n ? __pfx_do_raw_spin_lock+0x10/0x10\n ? __pfx___writeback_single_inode+0x10/0x10\n ? srso_alias_return_thunk+0x5/0xfbef5\n writeback_sb_inodes+0x65b/0x1810\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? lock_acquire+0x2b8/0x2f0\n ? __pfx_writeback_sb_inodes+0x10/0x10\n ? lock_release+0x1e0/0x280\n ? _raw_spin_unlock+0x23/0x40\n ? move_expired_inodes+0x2b8/0x850\n __writeback_inodes_wb+0xf4/0x270\n ? __pfx___writeback_inodes_wb+0x10/0x10\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? queue_io+0x2e4/0x410\n wb_writeback+0x666/0x880\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? __pfx_wb_writeback+0x10/0x10\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? get_nr_dirty_inodes+0x1c/0x170\n wb_workfn+0x75e/0xbb0\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? _raw_spin_unlock_irqrestore+0x27/0x60\n ? __pfx_wb_workfn+0x10/0x10\n ? __pfx_debug_object_deactivate+0x10/0x10\n ? lock_acquire+0x2b8/0x2f0\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? lock_release+0x1e0/0x280\n process_one_work+0x8d0/0x1870\n ? __pfx_process_one_work+0x10/0x10\n ? srso_alias_return_thunk+0x5/0xfbef5\n worker_thread+0x575/0xf80\n ? __pfx_worker_thread+0x10/0x10\n kthread+0x2e7/0x3c0\n ? __pfx_kthread+0x10/0x10\n ret_from_fork+0x576/0x810\n ? __pfx_ret_from_fork+0x10/0x10\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? __switch_to+0x57e/0xe10\n ? __switch_to_asm+0x33/0x70\n ? __pfx_kthread+0x10/0x10\n ret_from_fork_asm+0x1a/0x30\n </TASK>\n\nAllocated by task 970:\n kasan_save_stack+0x33/0x60\n kasan_save_track+0x14/0x30\n __kasan_kmalloc+0xaa/0xb0\n __kvmalloc_node_noprof+0x353/0x920\n ntfs_rl_realloc+0x3c/0x80\n ntfs_runlists_merge+0x1212/0x3010\n ntfs_mft_data_extend_allocation_nolock+0x3e0/0x1f40\n ntfs_mft_record_alloc+0x1ab4/0x4f10\n __ntfs_create+0x680/0x2e50\n ntfs_create+0x1e6/0x3a0\n path_openat+0x2b55/0x3c10\n do_file_open+0x1f4/0x460\n do_sys_openat2+0xde/0x170\n __x64_sys_openat+0x122/0x1e0\n do_syscall_64+0x115/0x6a0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nFreed by task 1294:\n kasan_save_\n---truncated---"
}
],
"lastModified": "2026-08-17T06:18:39.540",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}