{"api_version":"1","generated_at":"2026-08-17T16:01:16+00:00","cve":"CVE-2026-72353","urls":{"html":"https://cve.report/CVE-2026-72353","api":"https://cve.report/api/cve/CVE-2026-72353.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-72353","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-72353"},"summary":{"title":"ntfs: avoid stale runlist element dereference in fallocate","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: avoid stale runlist element dereference in fallocate\n\nntfs_attr_fallocate() allocates holes and delayed allocations inside\ninitialized size by looking up the current runlist element under\nni->runlist.lock. The returned struct runlist_element is only a borrowed\npointer into ni->runlist.rl. A writer can replace and free that array\nafter the read lock is dropped, so later reads of rl->lcn, rl->length and\nrl->vcn can touch freed memory.\n\nThe buggy scenario involves two paths, with each column showing the order\nwithin that path:\n\nntfs_attr_fallocate():\n  1. Take ni->runlist.lock for read.\n  2. Get rl from ntfs_attr_find_vcn_nolock().\n  3. Drop ni->runlist.lock.\n  4. Read rl->lcn, rl->length and rl->vcn.\n\nmmap page_mkwrite:\n  1. Enter ntfs_filemap_page_mkwrite().\n  2. Reach __ntfs_write_iomap_begin() and ntfs_attr_map_cluster().\n  3. Merge allocation state with ntfs_runlists_merge().\n  4. Reallocate ni->runlist.rl in ntfs_rl_realloc(), freeing the old array.\n\nValidation reproduced this kernel report:\nBUG: KASAN: slab-use-after-free in ntfs_attr_fallocate+0xbb8/0xd00\n\nCall Trace:\n <TASK>\n dump_stack_lvl+0x66/0xa0\n print_report+0xce/0x630\n ? ntfs_attr_fallocate+0xbb8/0xd00\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? __virt_addr_valid+0x20d/0x410\n ? ntfs_attr_fallocate+0xbb8/0xd00\n kasan_report+0xe0/0x110\n ? ntfs_attr_fallocate+0xbb8/0xd00\n ntfs_attr_fallocate+0xbb8/0xd00\n ? lock_acquire+0x2b8/0x2f0\n ? __pfx_ntfs_attr_fallocate+0x10/0x10\n ? 0xffffffffc0000095\n ? down_write+0x10d/0x1e0\n ntfs_fallocate+0x5c9/0x1d00\n ? __pfx_ntfs_fallocate+0x10/0x10\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? lock_acquire+0x2b8/0x2f0\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? selinux_file_permission+0x3a7/0x510\n vfs_fallocate+0x29d/0xd30\n __x64_sys_fallocate+0xc7/0x150\n ? do_syscall_64+0x81/0x6a0\n do_syscall_64+0x115/0x6a0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nAllocated by task 410:\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+0x3f/0x110\n ntfs_runlists_merge+0xaa3/0x3010\n ntfs_attr_map_cluster+0x4e5/0xf80\n ntfs_attr_fallocate+0x53f/0xd00\n ntfs_fallocate+0x5c9/0x1d00\n vfs_fallocate+0x29d/0xd30\n __x64_sys_fallocate+0xc7/0x150\n do_syscall_64+0x115/0x6a0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nFreed by task 424:\n kasan_save_stack+0x33/0x60\n kasan_save_track+0x14/0x30\n kasan_save_free_info+0x3b/0x60\n __kasan_slab_free+0x5f/0x80\n kfree+0x307/0x580\n ntfs_rl_realloc+0x6f/0x110\n ntfs_runlists_merge+0x7b1/0x3010\n ntfs_attr_map_cluster+0x4e5/0xf80\n __ntfs_write_iomap_begin+0x8cd/0x2280\n iomap_iter+0x6de/0x11e0\n iomap_page_mkwrite+0x391/0x650\n ntfs_filemap_page_mkwrite+0x1ac/0x400\n do_page_mkwrite+0x15c/0x280\n __handle_mm_fault+0xd6d/0x1ca0\n handle_mm_fault+0x19c/0x470\n do_user_addr_fault+0x23b/0x9c0\n exc_page_fault+0x5c/0xc0\n asm_exc_page_fault+0x26/0x30\n\nFix this by copying the needed runlist fields while the read lock is still\nheld and using only those scalar snapshots after unlocking.\n\nAfter the snapshot, ntfs_attr_map_cluster() can also find that the range\nis already mapped and return balloc=false. Only call ntfs_dio_zero_range()\nwhen new clusters were allocated, matching the write iomap path and\npreserving the zero-newly-allocated-holes behavior.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 06:22:08","updated_at":"2026-08-17 06:18:39"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"8.8","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"8.8","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":8.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/3dd3e43f17cda174009a51fe668046ed7afef46a","name":"https://git.kernel.org/stable/c/3dd3e43f17cda174009a51fe668046ed7afef46a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/88496c4ac5a6ade75619f4b1015706a8b924d50a","name":"https://git.kernel.org/stable/c/88496c4ac5a6ade75619f4b1015706a8b924d50a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-72353","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72353","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 495e90fa334828d4119061e2726af51d0a0fb4ed 3dd3e43f17cda174009a51fe668046ed7afef46a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 495e90fa334828d4119061e2726af51d0a0fb4ed 88496c4ac5a6ade75619f4b1015706a8b924d50a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.5 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"72353","cve":"CVE-2026-72353","epss":"0.001980000","percentile":"0.099000000","score_date":"2026-08-16","updated_at":"2026-08-17 00:01:05"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/ntfs/attrib.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"3dd3e43f17cda174009a51fe668046ed7afef46a","status":"affected","version":"495e90fa334828d4119061e2726af51d0a0fb4ed","versionType":"git"},{"lessThan":"88496c4ac5a6ade75619f4b1015706a8b924d50a","status":"affected","version":"495e90fa334828d4119061e2726af51d0a0fb4ed","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/ntfs/attrib.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"7.1"},{"lessThan":"7.1","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.5","versionStartIncluding":"7.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"7.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: avoid stale runlist element dereference in fallocate\n\nntfs_attr_fallocate() allocates holes and delayed allocations inside\ninitialized size by looking up the current runlist element under\nni->runlist.lock. The returned struct runlist_element is only a borrowed\npointer into ni->runlist.rl. A writer can replace and free that array\nafter the read lock is dropped, so later reads of rl->lcn, rl->length and\nrl->vcn can touch freed memory.\n\nThe buggy scenario involves two paths, with each column showing the order\nwithin that path:\n\nntfs_attr_fallocate():\n  1. Take ni->runlist.lock for read.\n  2. Get rl from ntfs_attr_find_vcn_nolock().\n  3. Drop ni->runlist.lock.\n  4. Read rl->lcn, rl->length and rl->vcn.\n\nmmap page_mkwrite:\n  1. Enter ntfs_filemap_page_mkwrite().\n  2. Reach __ntfs_write_iomap_begin() and ntfs_attr_map_cluster().\n  3. Merge allocation state with ntfs_runlists_merge().\n  4. Reallocate ni->runlist.rl in ntfs_rl_realloc(), freeing the old array.\n\nValidation reproduced this kernel report:\nBUG: KASAN: slab-use-after-free in ntfs_attr_fallocate+0xbb8/0xd00\n\nCall Trace:\n <TASK>\n dump_stack_lvl+0x66/0xa0\n print_report+0xce/0x630\n ? ntfs_attr_fallocate+0xbb8/0xd00\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? __virt_addr_valid+0x20d/0x410\n ? ntfs_attr_fallocate+0xbb8/0xd00\n kasan_report+0xe0/0x110\n ? ntfs_attr_fallocate+0xbb8/0xd00\n ntfs_attr_fallocate+0xbb8/0xd00\n ? lock_acquire+0x2b8/0x2f0\n ? __pfx_ntfs_attr_fallocate+0x10/0x10\n ? 0xffffffffc0000095\n ? down_write+0x10d/0x1e0\n ntfs_fallocate+0x5c9/0x1d00\n ? __pfx_ntfs_fallocate+0x10/0x10\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? lock_acquire+0x2b8/0x2f0\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? selinux_file_permission+0x3a7/0x510\n vfs_fallocate+0x29d/0xd30\n __x64_sys_fallocate+0xc7/0x150\n ? do_syscall_64+0x81/0x6a0\n do_syscall_64+0x115/0x6a0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nAllocated by task 410:\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+0x3f/0x110\n ntfs_runlists_merge+0xaa3/0x3010\n ntfs_attr_map_cluster+0x4e5/0xf80\n ntfs_attr_fallocate+0x53f/0xd00\n ntfs_fallocate+0x5c9/0x1d00\n vfs_fallocate+0x29d/0xd30\n __x64_sys_fallocate+0xc7/0x150\n do_syscall_64+0x115/0x6a0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nFreed by task 424:\n kasan_save_stack+0x33/0x60\n kasan_save_track+0x14/0x30\n kasan_save_free_info+0x3b/0x60\n __kasan_slab_free+0x5f/0x80\n kfree+0x307/0x580\n ntfs_rl_realloc+0x6f/0x110\n ntfs_runlists_merge+0x7b1/0x3010\n ntfs_attr_map_cluster+0x4e5/0xf80\n __ntfs_write_iomap_begin+0x8cd/0x2280\n iomap_iter+0x6de/0x11e0\n iomap_page_mkwrite+0x391/0x650\n ntfs_filemap_page_mkwrite+0x1ac/0x400\n do_page_mkwrite+0x15c/0x280\n __handle_mm_fault+0xd6d/0x1ca0\n handle_mm_fault+0x19c/0x470\n do_user_addr_fault+0x23b/0x9c0\n exc_page_fault+0x5c/0xc0\n asm_exc_page_fault+0x26/0x30\n\nFix this by copying the needed runlist fields while the read lock is still\nheld and using only those scalar snapshots after unlocking.\n\nAfter the snapshot, ntfs_attr_map_cluster() can also find that the range\nis already mapped and return balloc=false. Only call ntfs_dio_zero_range()\nwhen new clusters were allocated, matching the write iomap path and\npreserving the zero-newly-allocated-holes behavior."}],"metrics":[{"cvssV3_1":{"baseScore":8.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:N - Remote clients can reach ntfs_attr_fallocate via ksmbd or nfsd vfs_fallocate on NTFS-backed shares, while concurrent SMB/NFS writes trigger ntfs_attr_map_cluster/ntfs_runlists_merge to free the runlist during fallocate.\nAC:L - The attacker controls both race sides with parallel fallocate and write/mmap requests on the same NTFS file; the fix commit documents a reproducible KASAN slab-use-after-free from this attacker-driven concurrency.\nPR:L - Only write permission on a regular file on a mounted NTFS volume is required (local unprivileged user or authenticated SMB/NFS client), not real root in the initial mount namespace.\nUI:N - No victim interaction is needed during exploitation; the attacker prepares sparse/hole file state and drives fallocate plus concurrent writes without requiring another user to mount or open files.\nS:U - Impact is kernel heap corruption and privilege escalation within the host; it does not cross VM, hypervisor, or IOMMU security boundaries.\nC:H - Slab use-after-free on runlist_element fields (rl->lcn, rl->length, rl->vcn) reads freed kernel memory, enabling standard UAF-based arbitrary read and kernel pointer disclosure primitives.\nI:H - Freed runlist metadata influences subsequent cluster allocation and ntfs_dio_zero_range operations, providing UAF-based heap manipulation and arbitrary kernel write exploitation potential.\nA:H - Reproduced as KASAN slab-use-after-free in ntfs_attr_fallocate; stale runlist dereference can cause kernel oops, BUG, or panic when the race succeeds."}]}],"providerMetadata":{"dateUpdated":"2026-08-17T05:43:11.052Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/3dd3e43f17cda174009a51fe668046ed7afef46a"},{"url":"https://git.kernel.org/stable/c/88496c4ac5a6ade75619f4b1015706a8b924d50a"}],"title":"ntfs: avoid stale runlist element dereference in fallocate","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-72353","datePublished":"2026-08-15T05:55:55.480Z","dateReserved":"2026-08-09T03:40:39.921Z","dateUpdated":"2026-08-17T05:43:11.052Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-15 06:22:08","lastModifiedDate":"2026-08-17 06:18:39","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":2.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"72353","Ordinal":"1","Title":"ntfs: avoid stale runlist element dereference in fallocate","CVE":"CVE-2026-72353","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"72353","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: avoid stale runlist element dereference in fallocate\n\nntfs_attr_fallocate() allocates holes and delayed allocations inside\ninitialized size by looking up the current runlist element under\nni->runlist.lock. The returned struct runlist_element is only a borrowed\npointer into ni->runlist.rl. A writer can replace and free that array\nafter the read lock is dropped, so later reads of rl->lcn, rl->length and\nrl->vcn can touch freed memory.\n\nThe buggy scenario involves two paths, with each column showing the order\nwithin that path:\n\nntfs_attr_fallocate():\n  1. Take ni->runlist.lock for read.\n  2. Get rl from ntfs_attr_find_vcn_nolock().\n  3. Drop ni->runlist.lock.\n  4. Read rl->lcn, rl->length and rl->vcn.\n\nmmap page_mkwrite:\n  1. Enter ntfs_filemap_page_mkwrite().\n  2. Reach __ntfs_write_iomap_begin() and ntfs_attr_map_cluster().\n  3. Merge allocation state with ntfs_runlists_merge().\n  4. Reallocate ni->runlist.rl in ntfs_rl_realloc(), freeing the old array.\n\nValidation reproduced this kernel report:\nBUG: KASAN: slab-use-after-free in ntfs_attr_fallocate+0xbb8/0xd00\n\nCall Trace:\n <TASK>\n dump_stack_lvl+0x66/0xa0\n print_report+0xce/0x630\n ? ntfs_attr_fallocate+0xbb8/0xd00\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? __virt_addr_valid+0x20d/0x410\n ? ntfs_attr_fallocate+0xbb8/0xd00\n kasan_report+0xe0/0x110\n ? ntfs_attr_fallocate+0xbb8/0xd00\n ntfs_attr_fallocate+0xbb8/0xd00\n ? lock_acquire+0x2b8/0x2f0\n ? __pfx_ntfs_attr_fallocate+0x10/0x10\n ? 0xffffffffc0000095\n ? down_write+0x10d/0x1e0\n ntfs_fallocate+0x5c9/0x1d00\n ? __pfx_ntfs_fallocate+0x10/0x10\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? lock_acquire+0x2b8/0x2f0\n ? srso_alias_return_thunk+0x5/0xfbef5\n ? selinux_file_permission+0x3a7/0x510\n vfs_fallocate+0x29d/0xd30\n __x64_sys_fallocate+0xc7/0x150\n ? do_syscall_64+0x81/0x6a0\n do_syscall_64+0x115/0x6a0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nAllocated by task 410:\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+0x3f/0x110\n ntfs_runlists_merge+0xaa3/0x3010\n ntfs_attr_map_cluster+0x4e5/0xf80\n ntfs_attr_fallocate+0x53f/0xd00\n ntfs_fallocate+0x5c9/0x1d00\n vfs_fallocate+0x29d/0xd30\n __x64_sys_fallocate+0xc7/0x150\n do_syscall_64+0x115/0x6a0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nFreed by task 424:\n kasan_save_stack+0x33/0x60\n kasan_save_track+0x14/0x30\n kasan_save_free_info+0x3b/0x60\n __kasan_slab_free+0x5f/0x80\n kfree+0x307/0x580\n ntfs_rl_realloc+0x6f/0x110\n ntfs_runlists_merge+0x7b1/0x3010\n ntfs_attr_map_cluster+0x4e5/0xf80\n __ntfs_write_iomap_begin+0x8cd/0x2280\n iomap_iter+0x6de/0x11e0\n iomap_page_mkwrite+0x391/0x650\n ntfs_filemap_page_mkwrite+0x1ac/0x400\n do_page_mkwrite+0x15c/0x280\n __handle_mm_fault+0xd6d/0x1ca0\n handle_mm_fault+0x19c/0x470\n do_user_addr_fault+0x23b/0x9c0\n exc_page_fault+0x5c/0xc0\n asm_exc_page_fault+0x26/0x30\n\nFix this by copying the needed runlist fields while the read lock is still\nheld and using only those scalar snapshots after unlocking.\n\nAfter the snapshot, ntfs_attr_map_cluster() can also find that the range\nis already mapped and return balloc=false. Only call ntfs_dio_zero_range()\nwhen new clusters were allocated, matching the write iomap path and\npreserving the zero-newly-allocated-holes behavior.","Type":"Description","Title":"ntfs: avoid stale runlist element dereference in fallocate"}]}}}