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TI-2026-60756 Aliases CVE-2026-89713GHSA-v99p-5h33-35p9

NFSD: check truncate permission under inode lock

Priority MEDIUM 46Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · 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: NFSD: check truncate permission under inode lock nfsd_setattr() checks whether a size update needs NFSD_MAY_TRUNC before it takes inode_lock(). The comparison uses the file size sampled by that unlocked read, but the actual ATTR_SIZE update is applied later under inode_lock() by notify_change(). This leaves a TOCTOU window for append-only files. If a client sends a SETATTR that does not shrink the file at the time of the unlocked sample, a concurrent append can extend the file before nfsd_setattr() takes inode_lock(). notify_change() then applies a real truncation without the NFSD_MAY_TRUNC check that rejects IS_APPEND(inode). The VFS truncate syscall paths perform their own append-only checks before calling notify_change(), so NFSD must make this decision against the locked size it is about to change. Split the write-count acquisition from the truncation permission check. Keep get_write_access() before the locked setattr work, then recheck whether the requested size is below i_size_read(inode) after inode_lock() has been acquired and before notify_change(ATTR_SIZE). This also avoids the plain unlocked inode->i_size load.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00665 52nd percentileScored 2026-11-07
Fix Partial Linux (Linux): 3.3, 3.17, 4.5 +8Red Hat: 4 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux3.2.89 to before 3.3; 3.16.44 to before 3.17; 4.4.53 to before 4.5; 4.9.14 to before 4.10; 4.10.2 to before 4.113.3, 3.17, 4.5, 4.10, 4.11Patch availableCNA
LinuxLinux4.11 and later6.1.191, 6.6.160, 6.12.109, 6.18.50, 7.2.4, 7.3Patch availableCNA
  • Linux VendorLinux Affected 3.2.89 to before 3.3; 3.16.44 to before 3.17; 4.4.53 to before 4.5; 4.9.14 to before 4.10; 4.10.2 to before 4.11 Fixed in 3.3, 3.17, 4.5, 4.10, 4.11 Patch available CNA
  • Linux VendorLinux Affected 4.11 and later Fixed in 6.1.191, 6.6.160, 6.12.109, 6.18.50, 7.2.4, 7.3 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 3.3, 3.17, 4.5, 4.10, 4.11
  • Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.6.160, 6.12.109, 6.18.50, 7.2.4, 7.3

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet
Red Hat Enterprise Linux 7AffectedNo fix yet
Red Hat Enterprise Linux 8AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo fix yet
Not affected: 1 product
  • Red Hat Enterprise Linux 6

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-89713
  2. 2026-10-03 Alias added: GHSA-v99p-5h33-35p9
  3. 2026-10-18 CISA SSVC decision points changed
  4. 2026-10-19 Fix available: Linux/[email protected] · CNA
  5. 2026-10-21 Fix available: Linux/Linux@52d0c5bdfe232c9974d4b11f97078b9c7814f05d, Linux/[email protected] · CNA
  6. 2026-10-21 1 new reference · CNA
  7. 2026-10-30 Affected versions changed · Red Hat
  8. 2026-10-30 Fix available: Linux/Linux@0669861a2e8e2bdb9c1149417d8ad821996ae4fe, Linux/[email protected] · CNA
  9. 2026-10-30 1 new reference · CNA
  10. 2026-10-31 EPSS moved to the 50th–90th percentile
  11. 2026-11-01 Affected versions changed · Red Hat
  12. 2026-11-01 CVSS score changed · Red Hat

References

Other 6

  • 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