CVE-2021-47638

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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
DEBIAN (1)
SUSE (4)
UBUNTU (1)
Related
SUSE (4)
Published
2025-02-26T06:37:05Z
Modified
2026-03-10T13:44:54Z
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: 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).

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"
            }
        ]
    }
]