High 7.8Published Sep 24, 2026

CVE-2026-93798btrfs: fix reloc root cleanup in merge_reloc_roots()

Updated under an hour ago (Oct 27, 2026, 11:00 AM ET)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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.

CVSS: 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Received
Record last updated: Oct 3, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 1dae7e0e58b484eaa43d530f211098fdeeb0f404 before 29531470b1bf1e8bd2df4941fe913106edbca615; from 1dae7e0e58b484eaa43d530f211098fdeeb0f404 before 415f8665a969d3c906e4fd7c90fcbb4b357886f6; from 1dae7e0e58b484eaa43d530f211098fdeeb0f404 before ee695a968aa73b1e67ccbf2133dc0e54381d32b2; 1dae7e0e58b484eaa43d530f211098fdeeb0f404 builds before 0bc25f0a2d1b3e0a691431c4d7aef36afcd527c5; from 1dae7e0e58b484eaa43d530f211098fdeeb0f404 before ab48583aa9948205ff9a6470e23dbff74c565e24; from 1dae7e0e58b484eaa43d530f211098fdeeb0f404 before 63d6b1f04cd91c825329712aa526215ffa5d11ca; from 1dae7e0e58b484eaa43d530f211098fdeeb0f404 before b78fe9563e2d5ae47805f1e5dc722c91fd30e1f8; ee08663380ffd5a45a1c87580fbc305e8413c235; and 3 more ranges	CNA record

References

References

https://git.kernel.org/stable/c/29531470b1bf1e8bd2df4941fe913106edbca615
https://git.kernel.org/stable/c/415f8665a969d3c906e4fd7c90fcbb4b357886f6
https://git.kernel.org/stable/c/ee695a968aa73b1e67ccbf2133dc0e54381d32b2
https://git.kernel.org/stable/c/0bc25f0a2d1b3e0a691431c4d7aef36afcd527c5
https://git.kernel.org/stable/c/ab48583aa9948205ff9a6470e23dbff74c565e24
https://git.kernel.org/stable/c/63d6b1f04cd91c825329712aa526215ffa5d11ca
https://git.kernel.org/stable/c/b78fe9563e2d5ae47805f1e5dc722c91fd30e1f8

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.