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TI-2026-62847 Aliases CVE-2026-93228GHSA-g29j-c673-5ccw

svcrdma: Reject Write/Reply chunks with segcount 0

Priority MEDIUM 40Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · None · High
Fix status
Partial Red Hat: 17 fixed, 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: svcrdma: Reject Write/Reply chunks with segcount 0 A peer can send a Write or Reply chunk whose segcount field is zero. xdr_check_write_chunk() only rejects segcount > rc_maxpages, so zero passes the range check, and xdr_inline_decode(stream, 0) returns the current (non-NULL) cursor without advancing. The function returns true and pcl_alloc_write() then links a struct svc_rdma_chunk with ch_segcount == 0 onto rc_write_pcl or rc_reply_pcl. An earlier patch in this series made pcl_for_each_segment() safe for ch_segcount == 0, so this no longer drives the memory walk it used to. Rejecting the malformed frame at the decode boundary is still worthwhile as defense in depth: it keeps degenerate zero-segment chunks off the parsed chunk lists entirely, so any future consumer that walks ch_segments directly cannot observe one, and it makes the zero-floor easy to backport to trees where the macro change is more intrusive. RFC 8166 has no meaning for a Write/Reply chunk that describes no remote buffer, so no legitimate client is affected. xdr_check_reply_chunk() funnels Reply chunks through xdr_check_write_chunk() and inherits the same rejection. pcl_alloc_write() also links each chunk onto the parsed chunk list before filling its segment array. If a future change weakens the segcount-0 rejection, an incomplete chunk is visible to consumers during the fill loop. Reorder so that list_add_tail() follows the segment fill loop, ensuring only fully-populated chunks appear on the list.

Why it matters now

EPSS 0.00501 43rd percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.1.191, 6.6.160, 6.12.111 +3Red Hat: 5 advisoriesRed Hat: 17 fixed, 4 without a fix

SSVC decision points

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

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux5.11 and later6.1.191, 6.6.160, 6.12.111, 6.18.50, 7.2.4, 7.3Patch availableCNA
  • Linux VendorLinux Affected 5.11 and later Fixed in 6.1.191, 6.6.160, 6.12.111, 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 6.1.191, 6.6.160, 6.12.111, 6.18.50, 7.2.4, 7.3

Red Hat 5 advisories

  • RHSA-2026:89197 Released 2026-10-27 · Red Hat rating Critical
    OpenShift Container Platform 4.22.20 bug fix and security update
    • Red Hat OpenShift Container Platform 4.22 rhcos-aarch64-4.22.9.8.202610241758-0, rhcos-ppc64le-4.22.9.8.202610241758-0, rhcos-s390x-4.22.9.8.202610241758-0 +1
  • RHSA-2026:83207 Released 2026-10-15 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • 10Base-SMTV kernel-modules-internal-6.12.0-211.66.1.el10_2
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.66.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.66.1.el10_2, kernel-64k-devel-6.12.0-211.66.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.66.1.el10_2, kernel-64k-6.12.0-211.66.1.el10_2, kernel-64k-core-6.12.0-211.66.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.66.1.el10_2, libperf-6.12.0-211.66.1.el10_2
    • Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal-6.12.0-211.66.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.66.1.el10_2, kernel-rt-64k-6.12.0-211.66.1.el10_2, kernel-rt-64k-core-6.12.0-211.66.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.66.1.el10_2, kernel-rt-core-6.12.0-211.66.1.el10_2, kernel-rt-debug-6.12.0-211.66.1.el10_2 +9
  • RHSA-2026:83156 Released 2026-10-14 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.58.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.58.1.el9_8, kernel-64k-devel-5.14.0-687.58.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.58.1.el9_8, kernel-64k-5.14.0-687.58.1.el9_8, kernel-64k-core-5.14.0-687.58.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.58.1.el9_8, libperf-5.14.0-687.58.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.58.1.el9_8, kernel-rt-64k-5.14.0-687.58.1.el9_8, kernel-rt-64k-core-5.14.0-687.58.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.58.1.el9_8, kernel-rt-core-5.14.0-687.58.1.el9_8, kernel-rt-debug-5.14.0-687.58.1.el9_8 +9
Show 2 more Red Hat advisories
  • RHSA-2026:83157 Released 2026-10-14 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.174.1.el8_10, kernel-4.18.0-553.174.1.el8_10, kernel-abi-stablelists-4.18.0-553.174.1.el8_10 +19
    • Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.174.1.el8_10
  • RHSA-2026:83159 Released 2026-10-14 · Red Hat rating Important
    kernel-rt security, bug fix, and enhancement update
    • Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.174.1.rt7.515.el8_10, kernel-rt-core-4.18.0-553.174.1.rt7.515.el8_10, kernel-rt-debug-4.18.0-553.174.1.rt7.515.el8_10 +9
    • Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.174.1.rt7.515.el8_10, kernel-rt-core-4.18.0-553.174.1.rt7.515.el8_10, kernel-rt-debug-4.18.0-553.174.1.rt7.515.el8_10 +7

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat OpenShift Container Platform 4AffectedNo fix yet
Red Hat OpenShift Container Platform 5AffectedNo fix yet
10Base-SMTVFixed RHSA-2026:83207
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:83207
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:83156
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:83207
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2026:83157
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:83156
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:83157
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:83207
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:83156
Red Hat Enterprise Linux Hidden (v. 10)Fixed RHSA-2026:83207
Red Hat Enterprise Linux NFV (v. 8)Fixed RHSA-2026:83159
Red Hat Enterprise Linux RT (v. 8)Fixed RHSA-2026:83159
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:83207
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:83156
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:83207
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:83156
Red Hat OpenShift Container Platform 4.22Fixed RHSA-2026:89197
Not affected: 1 product
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-93228
  2. 2026-10-03 Alias added: GHSA-g29j-c673-5ccw
  3. 2026-10-16 Fix available: RHSA-2026:83159 · Red Hat
  4. 2026-10-16 Fix available: RHSA-2026:83156 · Red Hat
  5. 2026-10-16 Fix available: RHSA-2026:83157 · Red Hat
  6. 2026-10-16 Fix available: RHSA-2026:83207 · Red Hat
  7. 2026-10-16 Fix available: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux AppStream (v. 9) +13 · Red Hat
  8. 2026-10-19 Fix available: Linux/[email protected] · CNA
  9. 2026-10-21 Fix available: Linux/Linux@28c5a3a572f6cf81ac304459cfd515480995d62a, Linux/[email protected] · CNA
  10. 2026-10-21 1 new reference · CNA
  11. 2026-10-29 Fix available: RHSA-2026:89197 · Red Hat
  12. 2026-10-29 Fix available: Red Hat OpenShift Container Platform 4.22 · Red Hat
  13. 2026-10-30 Affected versions changed · Red Hat
  14. 2026-10-30 Fix available: Linux/[email protected], Linux/Linux@ac730b8cbaeec6831116e1455d909ecbdcdcbd34 · CNA
  15. 2026-10-30 1 new reference · CNA

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 21727 →

Sources

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