CVE-2021-47638

Source
https://cve.org/CVERecord?id=CVE-2021-47638
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-47638.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2021-47638
Downstream
Related
Published
2025-02-26T06:37:05.580Z
Modified
2026-03-10T13:44:54.557128Z
Severity
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
[none]
Details

In the Linux kernel, the following vulnerability has been resolved:

ubifs: renamewhiteout: Fix double free for whiteoutui->data

'whiteout_ui->data' will be freed twice if space budget fail for rename whiteout operation as following process:

renamewhiteout dev = kmalloc whiteoutui->data = dev kfree(whiteoutui->data) // Free first time iput(whiteout) ubifsfree_inode kfree(ui->data) // Double free!

KASAN reports:

BUG: KASAN: double-free or invalid-free in ubifsfreeinode+0x4f/0x70 Call Trace: kfree+0x117/0x490 ubifsfreeinode+0x4f/0x70 [ubifs] icallback+0x30/0x60 rcudo_batch+0x366/0xac0 _dosoftirq+0x133/0x57f

Allocated by task 1506: kmemcachealloctrace+0x3c2/0x7a0 dorename+0x9b7/0x1150 [ubifs] ubifsrename+0x106/0x1f0 [ubifs] dosyscall_64+0x35/0x80

Freed by task 1506: kfree+0x117/0x490 dorename.cold+0x53/0x8a [ubifs] ubifsrename+0x106/0x1f0 [ubifs] dosyscall64+0x35/0x80

The buggy address belongs to the object at ffff88810238bed8 which

belongs to the cache kmalloc-8 of size 8

Let ubifsfreeinode() free 'whiteoutui->data'. BTW, delete unused assignment 'whiteoutui->datalen = 0', process 'ubifsevictinode() -> ubifsjnldeleteinode() -> ubifsjnlwriteinode()' doesn't need it (because 'incnlink(whiteout)' won't be excuted by 'goto out_release', and the nlink of whiteout inode is 0).

References

Affected packages

Git /

Affected ranges

Database specific

source
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-47638.json"
unresolved_ranges
[
    {
        "events": [
            {
                "introduced": "4.9"
            },
            {
                "fixed": "4.14.276"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "4.15"
            },
            {
                "fixed": "4.19.238"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "4.20"
            },
            {
                "fixed": "5.4.189"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "5.5"
            },
            {
                "fixed": "5.10.110"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "5.11"
            },
            {
                "fixed": "5.15.33"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "5.16"
            },
            {
                "fixed": "5.16.19"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "5.17"
            },
            {
                "fixed": "5.17.2"
            }
        ]
    }
]