CVE-2026-23285

Analyzed Analyzed - Analysis Complete

Null Pointer Dereference in Linux DRBD Causes Read Errors

Publication date: 2026-03-25

Last updated on: 2026-05-22

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: drbd: fix null-pointer dereference on local read error In drbd_request_endio(), READ_COMPLETED_WITH_ERROR is passed to __req_mod() with a NULL peer_device: __req_mod(req, what, NULL, &m); The READ_COMPLETED_WITH_ERROR handler then unconditionally passes this NULL peer_device to drbd_set_out_of_sync(), which dereferences it, causing a null-pointer dereference. Fix this by obtaining the peer_device via first_peer_device(device), matching how drbd_req_destroy() handles the same situation.

CVSS Scores

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Meta Information

Published

2026-03-25

Last Modified

2026-05-22

Generated

2026-07-06

AI Q&A

2026-03-25

EPSS Evaluated

2026-07-05

NVD

CVE-2026-23285

EUVD

EUVD-2026-15211

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	From 6.19 (inc) to 6.19.7 (exc)
linux	linux_kernel	7.0
linux	linux_kernel	From 6.13 (inc) to 6.18.17 (exc)
linux	linux_kernel	From 6.7 (inc) to 6.12.77 (exc)
linux	linux_kernel	From 6.4 (inc) to 6.6.130 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-476	The product dereferences a pointer that it expects to be valid but is NULL.

Attack-Flow Graph

Impact Analysis

This vulnerability can cause a null-pointer dereference in the Linux kernel, which typically results in a kernel crash or system instability. Such crashes can lead to denial of service conditions, where the affected system becomes unresponsive or requires a reboot.

Executive Summary

This vulnerability is a null-pointer dereference in the Linux kernel's DRBD component. Specifically, in the function drbd_request_endio(), a NULL peer_device pointer is passed to the __req_mod() function when handling a local read error. This NULL pointer is then passed to drbd_set_out_of_sync(), which dereferences it, causing the kernel to attempt to access memory through a NULL pointer, leading to a crash or instability.

The fix involves correctly obtaining the peer_device pointer using first_peer_device(device), ensuring that the pointer is valid before it is used, matching the handling in a related function drbd_req_destroy().

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