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TI-2025-26860 Aliases CVE-2025-40190GHSA-j9x6-gmq6-xm5x

ext4: guard against EA inode refcount underflow in xattr update

Priority LOW 33Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 4 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: ext4: guard against EA inode refcount underflow in xattr update syzkaller found a path where ext4_xattr_inode_update_ref() reads an EA inode refcount that is already <= 0 and then applies ref_change (often -1). That lets the refcount underflow and we proceed with a bogus value, triggering errors like: EXT4-fs error: EA inode <n> ref underflow: ref_count=-1 ref_change=-1 EXT4-fs warning: ea_inode dec ref err=-117 Make the invariant explicit: if the current refcount is non-positive, treat this as on-disk corruption, emit ext4_error_inode(), and fail the operation with -EFSCORRUPTED instead of updating the refcount. Delete the WARN_ONCE() as negative refcounts are now impossible; keep error reporting in ext4_error_inode(). This prevents the underflow and the follow-on orphan/cleanup churn.

Why it matters now

EPSS 0.00178 7th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.4.301, 5.10.246, 5.15.195 +5Red Hat: 4 without a fix

SSVC decision points

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

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinuxbefore 5.4.301; before 5.10.246; before 5.15.195; before 6.1.157; before 6.6.113; before 6.12.54; before 6.17.45.4.301, 5.10.246, 5.15.195, 6.1.157, 6.6.113, 6.12.54, 6.17.4Patch availableCNA
LinuxLinux—5.4.301, 5.10.246, 5.15.195, 6.1.157, 6.6.113, 6.12.54, 6.17.4, 6.18Patch availableCNA
  • Linux VendorLinux Affected before 5.4.301; before 5.10.246; before 5.15.195; before 6.1.157; before 6.6.113; before 6.12.54; before 6.17.4 Fixed in 5.4.301, 5.10.246, 5.15.195, 6.1.157, 6.6.113, 6.12.54, 6.17.4 Patch available CNA
  • Linux VendorLinux Affected — Fixed in 5.4.301, 5.10.246, 5.15.195, 6.1.157, 6.6.113, 6.12.54, 6.17.4, 6.18 Patch available CNA

CPE names Threatist (inferred) · 1

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

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

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.4.301, 5.10.246, 5.15.195, 6.1.157, 6.6.113, 6.12.54, 6.17.4
  • Fix · CNA Linux (Linux) Fixed in 5.4.301, 5.10.246, 5.15.195, 6.1.157, 6.6.113, 6.12.54, 6.17.4, 6.18

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 8AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux 9AffectedNo fix yet
Not affected: 1 product
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-40190
  2. 2026-10-03 Alias added: GHSA-j9x6-gmq6-xm5x

References

Other 8

  • 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 21741 →

Sources

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