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CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2021-47638MEDIUM
Linux Linux — ubifs: rename_whiteout: Fix double free for whiteout_ui->data
  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   L   L   N  U  N  N  H    5.5   .0026   17.3     —
AFFECTED
  Product  Versions                                    Fixed
  Linux    9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 –  —
  Linux    4.9 –                                       4.14.276
TIMELINE
  Feb 26  Reserved by Linux
  Feb 26  Published (CNA: Linux)
  Aug 4   RESCORED — CVE-2021-47638 (Linux). CVSS 7.8 → 5.5 (NVD).
CWE-415 · CNA: Linux · CVSS v3.1 · 8 references · NVD status: Modified

Description

In the Linux kernel, the following vulnerability has been resolved: ubifs: rename_whiteout: Fix double free for whiteout_ui->data 'whiteout_ui->data' will be freed twice if space budget fail for rename whiteout operation as following process: rename_whiteout dev = kmalloc whiteout_ui->data = dev kfree(whiteout_ui->data) // Free first time iput(whiteout) ubifs_free_inode kfree(ui->data) // Double free! KASAN reports: ================================================================== BUG: KASAN: double-free or invalid-free in ubifs_free_inode+0x4f/0x70 Call Trace: kfree+0x117/0x490 ubifs_free_inode+0x4f/0x70 [ubifs] i_callback+0x30/0x60 rcu_do_batch+0x366/0xac0 __do_softirq+0x133/0x57f Allocated by task 1506: kmem_cache_alloc_trace+0x3c2/0x7a0 do_rename+0x9b7/0x1150 [ubifs] ubifs_rename+0x106/0x1f0 [ubifs] do_syscall_64+0x35/0x80 Freed by task 1506: kfree+0x117/0x490 do_rename.cold+0x53/0x8a [ubifs] ubifs_rename+0x106/0x1f0 [ubifs] do_syscall_64+0x35/0x80 The buggy address belongs to the object at ffff88810238bed8 which belongs to the cache kmalloc-8 of size 8 ================================================================== Let ubifs_free_inode() free 'whiteout_ui->data'. BTW, delete unused assignment 'whiteout_ui->data_len = 0', process 'ubifs_evict_inode() -> ubifs_jnl_delete_inode() -> ubifs_jnl_write_inode()' doesn't need it (because 'inc_nlink(whiteout)' won't be excuted by 'goto out_release', and the nlink of whiteout inode is 0).

Lifecycle

Complete event history — 3 events, chronological
DateEventDetail
February 26, 2025ReservedReserved by Linux
February 26, 2025PublishedPublished (CNA: Linux)
August 4, 2026RESCOREDRESCORED — CVE-2021-47638 (Linux). CVSS 7.8 → 5.5 (NVD).

Affected

Affected products and packages — 2 rows
VendorProduct / PackageEcosystemVersion introducedFixed
LinuxLinux9e0a1fff8db56eaaebb74b4a3ef65f86811c4798
LinuxLinux4.94.14.276

Weaknesses

CWE-415

References (8)

Related

Authoritative record: CVE-2021-47638 at cve.org

Vendors: linux

Weaknesses: CWE-415

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-47638 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.