Description
In the Linux kernel, the following vulnerability has been resolved:

rbd: Reset positive result codes to zero in object map update path

In a reply message to an RBD request, a positive result code indicates
a data payload, which is not allowed for writes. While
rbd_osd_req_callback() already resets a positive result code for writes
to zero, rbd_object_map_callback() does not. This allows a corrupted
reply to an object map update to trigger the rbd_assert(*result < 0) in
__rbd_obj_handle_request(). This happens, because
rbd_object_map_callback() calls rbd_obj_handle_request() ->
__rbd_obj_handle_request() and passes this positive result code. From
__rbd_obj_handle_request(), rbd_obj_advance_write() is called, which
leaves the positive result code unchanged and returns true. Therefore,
the if(done && *result) branch is executed in __rbd_obj_handle_request()
and the assertion triggers.

This patch fixes the issue by adjusting the logic in the
rbd_object_map_callback() path. A positive result code for an object map
update is now reset to zero (similar to rbd_osd_req_callback()), and the
message is subsequently handled the same way as if the result code was
zero from the beginning. Additionally, a WARN_ON_ONCE() is added for
this case.
Published: 2026-08-10
Score: 7.5 High
EPSS: < 1% Very Low
KEV: No
Impact: Denial of Service (Kernel Crash)
Action: Apply Patch
AI Analysis

Impact

The vulnerability stems from the Linux kernel's RBD (RADOS Block Device) subsystem, specifically within the object‑map update callback. A positive result code in a reply to an object‑map update is incorrectly passed to the request handler without being reset to zero, which triggers an assertion meant to check negative error codes. This causes a kernel panic and loss of availability for the node.

Affected Systems

All Linux kernel installations that ship the RBD module enabled are affected. Any distribution that includes the default kernel with RBD support, regardless of Ceph configuration, can experience this flaw if an attacker can influence the content of an object‑map reply.

Risk and Exploitability

The CVSS score is 7.5, indicating high severity, while the EPSS score of <1% suggests a very low yet non‑zero exploitation probability. The flaw is not listed in the CISA KEV catalog. The primary impact is a complete denial of service from a kernel crash. An attacker would need to supply a malformed RBD reply, which generally requires control over a Ceph OSD or the ability to tamper with traffic between the client and the OSD. This inferred attack vector limits widespread exploitation, but the high impact warrants prompt patching when available.

Generated by OpenCVE AI on October 20, 2026 at 10:20 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Update the kernel to a version that incorporates the rbd_object_map_callback fix commit referenced in the supplied Git commits.
  • If a direct kernel upgrade is not feasible, backport the specific changes from those commits to the running kernel under development.
  • If patching or backporting is impossible, isolate the host from the Ceph cluster or restrict the network path to trusted nodes and monitor for anomalous RBD traffic.

Generated by OpenCVE AI on October 20, 2026 at 10:20 UTC.

Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4745-1 linux-6.12 security update
Debian DLA Debian DLA DLA-4777-1 linux security update
Ubuntu USN Ubuntu USN USN-8876-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8875-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8877-1 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-8878-1 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-8879-1 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-8887-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8888-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8889-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8887-2 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8888-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8875-2 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8887-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8917-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8918-1 Linux kernel (Azure) vulnerabilities
History

Mon, 19 Oct 2026 21:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 19 Aug 2026 16:45:00 +0000


Fri, 14 Aug 2026 02:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-598
CWE-703

Thu, 13 Aug 2026 22:45:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Wed, 12 Aug 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-617
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Mon, 10 Aug 2026 19:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-598
CWE-703

Mon, 10 Aug 2026 12:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: rbd: Reset positive result codes to zero in object map update path In a reply message to an RBD request, a positive result code indicates a data payload, which is not allowed for writes. While rbd_osd_req_callback() already resets a positive result code for writes to zero, rbd_object_map_callback() does not. This allows a corrupted reply to an object map update to trigger the rbd_assert(*result < 0) in __rbd_obj_handle_request(). This happens, because rbd_object_map_callback() calls rbd_obj_handle_request() -> __rbd_obj_handle_request() and passes this positive result code. From __rbd_obj_handle_request(), rbd_obj_advance_write() is called, which leaves the positive result code unchanged and returns true. Therefore, the if(done && *result) branch is executed in __rbd_obj_handle_request() and the assertion triggers. This patch fixes the issue by adjusting the logic in the rbd_object_map_callback() path. A positive result code for an object map update is now reset to zero (similar to rbd_osd_req_callback()), and the message is subsequently handled the same way as if the result code was zero from the beginning. Additionally, a WARN_ON_ONCE() is added for this case.
Title rbd: Reset positive result codes to zero in object map update path
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-19T20:58:52.688Z

Reserved: 2026-07-30T09:28:09.370Z

Link: CVE-2026-68131

cve-icon Vulnrichment

Updated: 2026-10-16T15:44:27.347Z

cve-icon NVD

Status : Received

Published: 2026-08-10T13:19:58.460

Modified: 2026-10-19T21:17:53.150

Link: CVE-2026-68131

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-10T11:58:54Z

Links: CVE-2026-68131 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-20T10:30:06Z

Weaknesses