Double Free Affecting kernel-64kb-devel package, versions <5.14.21-150400.24.158.1


Severity

Recommended
0.0
high
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.04% (16th percentile)

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  • Snyk IDSNYK-SLES154-KERNEL64KBDEVEL-9526825
  • published27 Mar 2025
  • disclosed26 Mar 2025

Introduced: 26 Mar 2025

NewCVE-2021-47638  (opens in a new tab)
CWE-415  (opens in a new tab)

How to fix?

Upgrade SLES:15.4 kernel-64kb-devel to version 5.14.21-150400.24.158.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-64kb-devel package and not the kernel-64kb-devel package as distributed by SLES. See How to fix? for SLES:15.4 relevant fixed versions and status.

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).

CVSS Base Scores

version 3.1