CVE-2026-72354 — ntfs: avoid stale runlist element dereference in MFT writeback
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. 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. 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---
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.5% (30-day exploitation probability)+6
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.8 | CVSS 3.1 | High | 2.8 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 8.8 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- CVSS changed · 8.8
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
2 on the record
Elsewhere on this site
Related CVEs (same products)
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- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 15h
- Unknown CVE-2026-98431 RDMA/uverbs: Fix mmap_lock/disassociation_lock circular dependency 1d
- Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 1d
- Unknown CVE-2026-98429 RDMA/efa: Keep EQ resources alive while IRQ is registered 1d
- Unknown CVE-2026-98428 ALSA: usb: 6fire: Avoid embedded URBs 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-72354 is "ntfs: avoid stale runlist element dereference in MFT writeback", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.8 describes technical severity. EPSS 0.51% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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