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.
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).
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
| Date | Event | Detail |
| February 26, 2025 | Reserved | Reserved by Linux |
| February 26, 2025 | Published | Published (CNA: Linux) |
| August 4, 2026 | RESCORED | RESCORED — CVE-2021-47638 (Linux). CVSS 7.8 → 5.5 (NVD). |
Affected
Affected products and packages — 2 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
| Linux | Linux | — | 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 | — |
| Linux | Linux | — | 4.9 | 4.14.276 |
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.