CVE-2026-68131
Received Received - Intake

Buffer Overflow in Linux Kernel RBD Module

Vulnerability report for CVE-2026-68131, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-08-10

Last updated on: 2026-08-10

Assigner: kernel.org

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.

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Meta Information

Published
2026-08-10
Last Modified
2026-08-10
Generated
2026-08-10
AI Q&A
2026-08-10
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux_kernel linux_kernel *

Helpful Resources

Exploitability

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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves a flaw in the RBD (RADOS Block Device) object map update path. A corrupted reply message with a positive result code for a write operation can trigger an assertion failure in __rbd_obj_handle_request(). The issue occurs because rbd_object_map_callback() does not reset positive result codes to zero like rbd_osd_req_callback() does, leading to an invalid data payload being processed.

Detection Guidance

Detection requires kernel-level inspection. Check for kernel logs for rbd-related errors or assertions. Commands like dmesg | grep rbd or journalctl -k | grep rbd may reveal issues. Ensure kernel version is updated to a patched release.

Impact Analysis

This vulnerability could cause system crashes or instability in systems using RBD, particularly those relying on object map updates. An attacker exploiting this flaw might trigger kernel panics or denial-of-service conditions by sending maliciously crafted replies to RBD requests.

Mitigation Strategies

Update the Linux kernel to the latest stable version that includes the fix for this vulnerability. Monitor kernel logs for rbd-related errors after applying updates.

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