CVE-2026-72353: Software Security Vulnerability Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-7mwr-cgqq-xj42",
  "modified" : "2026-08-17T06:33:25Z",
  "published" : "2026-08-15T06:32:21Z",
  "aliases" : [ "CVE-2026-72353" ],
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-72353"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/3dd3e43f17cda174009a51fe668046ed7afef46a"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/88496c4ac5a6ade75619f4b1015706a8b924d50a"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-15T06:22:08Z"
  }
}