CVE-2023-53618

MEDIUM EPSS 7.9%
Published Oct 7, 20258mo ago · Modified Jun 17, 20262w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Oct 7, 2025 8mo ago
Last Modified Jun 17, 2026 2w ago

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: reject invalid reloc tree root keys with stack dump [BUG] Syzbot reported a crash that an ASSERT() got triggered inside prepare_to_merge(). That ASSERT() makes sure the reloc tree is properly pointed back by its subvolume tree. [CAUSE] After more debugging output, it turns out we had an invalid reloc tree: BTRFS error (device loop1): reloc tree mismatch, root 8 has no reloc root, expect reloc root key (-8, 132, 8) gen 17 Note the above root key is (TREE_RELOC_OBJECTID, ROOT_ITEM, QUOTA_TREE_OBJECTID), meaning it's a reloc tree for quota tree. But reloc trees can only exist for subvolumes, as for non-subvolume trees, we just COW the involved tree block, no need to create a reloc tree since those tree blocks won't be shared with other trees. Only subvolumes tree can share tree blocks with other trees (thus they have BTRFS_ROOT_SHAREABLE flag). Thus this new debug output proves my previous assumption that corrupted on-disk data can trigger that ASSERT(). [FIX] Besides the dedicated fix and the graceful exit, also let tree-checker to check such root keys, to make sure reloc trees can only exist for subvolumes.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
7.9% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Affected Products 9

VendorProductVersionRange
linuxlinux_kernel*≥5.2.19  –  <5.3
linuxlinux_kernel*≥5.3.4  –  <5.15.127
linuxlinux_kernel*≥5.16  –  <6.1.46
linuxlinux_kernel*≥6.2  –  <6.4.11
linuxlinux_kernel6.5any
linuxlinux_kernel6.5any
linuxlinux_kernel6.5any
linuxlinux_kernel6.5any
linuxlinux_kernel6.5any

References 4

  • git.kernel.org https://git.kernel.org/stable/c/314135b7bae9618a317874ae195272682cf2d5d4
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3ae93b316ca4b8b3c33798ef1d210355f2fb9318
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6ebcd021c92b8e4b904552e4d87283032100796d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/84256e00eeca73c529fc6196e478cc89b8098157
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/314135b7bae9618a317874ae195272682cf2d5d4
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3ae93b316ca4b8b3c33798ef1d210355f2fb9318
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6ebcd021c92b8e4b904552e4d87283032100796d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/84256e00eeca73c529fc6196e478cc89b8098157
    Patch