TI-2026-63152 Aliases CVE-2026-93798 GHSA-9c2v-whhq-6g24

btrfs: fix reloc root cleanup in merge_reloc_roots()

LOW 33Published 2026-09-24 · Updated 2026-10-03

Key facts

Attack vector: Local
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: High · High · High
Fix status: Partial Red Hat: 2 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix reloc root cleanup in merge_reloc_roots() If the root we got has zero root refs in its root item, we are resetting the root's ->reloc_root without using barriers like we do everywhere else. Sashiko complained about this while reviewing another patch, and it's correct (see the Link tag below). Also, we should not clear BTRFS_ROOT_DEAD_RELOC_TREE from the root unless the root points to the reloc root we have. Fix this by using clear_reloc_root(), which issues the memory barrier after setting the root's ->reloc_root to NULL and before clearing the bit BTRFS_ROOT_DEAD_RELOC_TREE from the root.

Why it matters now

EPSS 0.00129 2nd percentileScored 2026-11-07

Fix Partial Linux (Linux): 5.5, 5.8, 5.10.271 +6Red Hat: 2 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Linux	Linux	5.4.54 to before 5.5; 5.7.11 to before 5.8	5.5, 5.8	Patch available	CNA
Linux	Linux	5.8 and later	5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.2	Patch available	CNA

Linux VendorLinux Affected 5.4.54 to before 5.5; 5.7.11 to before 5.8 Fixed in 5.5, 5.8 Patch available CNA
Linux VendorLinux Affected 5.8 and later Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.2 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:o:linux:linux_kernel::::::::	—	—	Linux

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

Fix · CNA Linux (Linux) Fixed in 5.5, 5.8
Fix · CNA Linux (Linux) Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.2

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Enterprise Linux 10	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 6	Affected	No fix planned: Out of support scope

Not affected: 5 products

Red Hat Enterprise Linux 7
Red Hat Enterprise Linux 8
Red Hat Enterprise Linux 9
Red Hat OpenShift Container Platform 4
Red Hat OpenShift Container Platform 5

Timeline

2026-10-02 Threatist record created from CVE-2026-93798
2026-10-03 Alias added: GHSA-9c2v-whhq-6g24
2026-10-03 Fix available: Linux/Linux@0bc25f0a2d1b3e0a691431c4d7aef36afcd527c5, Linux/Linux@29531470b1bf1e8bd2df4941fe913106edbca615, Linux/Linux@415f8665a969d3c906e4fd7c90fcbb4b357886f6 +5 · CNA
2026-10-03 4 new references · CNA
2026-11-07 Affected versions changed · Red Hat

References

Other 7

TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4

See all 21727 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences