Description
The Dhara flash translation layer disk driver (drivers/disk/ftl_dhara.c) implemented the dhara_nand_ callbacks so that, on a flash error, the error code was written unconditionally through the caller-supplied dhara_error_t err pointer (e.g. *err = DHARA_E_ECC in dhara_nand_read, and similar in dhara_nand_erase/prog/copy).

The upstream Dhara library calls these callbacks with err == NULL along its journal-resume binary search: find_last_checkblock() invokes find_checkblock(j, mid, &found, NULL), which forwards the NULL pointer into dhara_nand_read(). This path runs during disk_ftl_access_init() -> dhara_map_resume() whenever the FTL disk is mounted/initialised.

If a flash read error (uncorrectable ECC, bad block, controller error) occurs on one of the probed checkpoint pages, the driver dereferences and writes to NULL, faulting the kernel (denial of service). The trigger is conditioned on the NAND medium content/health, which can be influenced by media wear, induced faults, or a corrupted/crafted on-flash image.

The fix routes all error assignments through the library's NULL-safe dhara_set_error() helper. Affects Zephyr v4.4.0, where the driver was introduced.
Published: 2026-07-07
Score: 4.7 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The Dhara flash translation layer driver in Zephyr RTOS contains a null pointer dereference that occurs when a flash read error occurs during the journal-resume process. The driver unconditionally writes an error code through a pointer supplied by the Dhara library, but the library can pass a NULL pointer during journal resumption. When a checkpoint page fails to read, the driver dereferences this NULL pointer and crashes the kernel, resulting in a denial of service. This weakness is a classic Null Pointer Dereference (CWE‑476).

Affected Systems

Zephyr Project’s Zephyr RTOS version 4.4.0, where the offending Dhara driver was introduced. The available information does not specify which later releases contain the fix, so administrators should consult the vendor documentation or the referenced commit to determine if an updated firmware version is available.

Risk and Exploitability

The CVSS score of 4.7 indicates a moderate risk. The EPSS score is less than 1 %, and the vulnerability is not listed in the CISA KEV catalog, implying no known widespread exploitation. The attack requires a fault in the NAND medium—caused by media wear, induced hardware faults, or a maliciously crafted flash image—so the window for exploitation is limited to boot or mount time when the disk is initialized. Under these conditions, the kernel crash can be triggered, but the lack of publicly known exploits and the narrow execution path suggest a low probability of real‑world exploitation.

Generated by OpenCVE AI on July 25, 2026 at 20:55 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade Zephyr RTOS to a release that incorporates the Dhara driver fix, such as the commit a8371b0d4719efe37a66e2abb618ad9b81792212 or a downstream firmware version that applies that change.
  • If an OTA update or source upgrade is not possible, apply the patch from commit a8371b0d4719efe37a66e2abb618ad9b81792212 to the source tree, rebuild, and flash the updated firmware.
  • If neither option is immediately feasible, isolate the affected device, disable the FTL disk feature during boot, or monitor NAND health and replace flash if errors are detected.

Generated by OpenCVE AI on July 25, 2026 at 20:55 UTC.

Tracking

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Advisories

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History

Tue, 14 Jul 2026 19:00:00 +0000

Type Values Removed Values Added
Description The Dhara flash translation layer disk driver (drivers/disk/ftl_dhara.c) implemented the dhara_nand_ callbacks so that, on a flash error, the error code was written unconditionally through the caller-supplied dhara_error_t err pointer (e.g. *err = DHARA_E_ECC in dhara_nand_read, and similar in dhara_nand_erase/prog/copy). The upstream Dhara library calls these callbacks with err == NULL along its journal-resume binary search: find_last_checkblock() invokes find_checkblock(j, mid, &found, NULL), which forwards the NULL pointer into dhara_nand_read(). This path runs during disk_ftl_access_init() -> dhara_map_resume() whenever the FTL disk is mounted/initialised. If a flash read error (uncorrectable ECC, bad block, controller error) occurs on one of the probed checkpoint pages, the driver dereferences and writes to NULL, faulting the kernel (denial of service). The trigger is conditioned on the NAND medium content/health, which can be influenced by media wear, induced faults, or a corrupted/crafted on-flash image. The fix routes all error assignments through the library's NULL-safe dhara_set_error() helper. Affects Zephyr v4.4.0, where the driver was introduced. The Dhara flash translation layer disk driver (drivers/disk/ftl_dhara.c) implemented the dhara_nand_ callbacks so that, on a flash error, the error code was written unconditionally through the caller-supplied dhara_error_t err pointer (e.g. *err = DHARA_E_ECC in dhara_nand_read, and similar in dhara_nand_erase/prog/copy). The upstream Dhara library calls these callbacks with err == NULL along its journal-resume binary search: find_last_checkblock() invokes find_checkblock(j, mid, &found, NULL), which forwards the NULL pointer into dhara_nand_read(). This path runs during disk_ftl_access_init() -> dhara_map_resume() whenever the FTL disk is mounted/initialised. If a flash read error (uncorrectable ECC, bad block, controller error) occurs on one of the probed checkpoint pages, the driver dereferences and writes to NULL, faulting the kernel (denial of service). The trigger is conditioned on the NAND medium content/health, which can be influenced by media wear, induced faults, or a corrupted/crafted on-flash image. The fix routes all error assignments through the library's NULL-safe dhara_set_error() helper. Affects Zephyr v4.4.0, where the driver was introduced.

Tue, 07 Jul 2026 14:45:00 +0000

Type Values Removed Values Added
First Time appeared Zephyrproject
Zephyrproject zephyr
Vendors & Products Zephyrproject
Zephyrproject zephyr

Tue, 07 Jul 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Tue, 07 Jul 2026 13:15:00 +0000

Type Values Removed Values Added
Description The Dhara flash translation layer disk driver (drivers/disk/ftl_dhara.c) implemented the dhara_nand_ callbacks so that, on a flash error, the error code was written unconditionally through the caller-supplied dhara_error_t err pointer (e.g. *err = DHARA_E_ECC in dhara_nand_read, and similar in dhara_nand_erase/prog/copy). The upstream Dhara library calls these callbacks with err == NULL along its journal-resume binary search: find_last_checkblock() invokes find_checkblock(j, mid, &found, NULL), which forwards the NULL pointer into dhara_nand_read(). This path runs during disk_ftl_access_init() -> dhara_map_resume() whenever the FTL disk is mounted/initialised. If a flash read error (uncorrectable ECC, bad block, controller error) occurs on one of the probed checkpoint pages, the driver dereferences and writes to NULL, faulting the kernel (denial of service). The trigger is conditioned on the NAND medium content/health, which can be influenced by media wear, induced faults, or a corrupted/crafted on-flash image. The fix routes all error assignments through the library's NULL-safe dhara_set_error() helper. Affects Zephyr v4.4.0, where the driver was introduced.
Title NULL pointer dereference in Zephyr Dhara FTL disk driver on flash read error during journal resume
Weaknesses CWE-476
References
Metrics cvssV3_1

{'score': 4.7, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H'}

Subscriptions

Zephyrproject Zephyr
cve-icon MITRE

Status: PUBLISHED

Assigner: zephyr

Published:

Updated: 2026-07-14T18:38:42.162Z

Reserved: 2026-06-02T15:24:36.650Z

Link: CVE-2026-10659

cve-icon Vulnrichment

Updated: 2026-07-07T13:24:23.052Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-07-25T21:00:14Z

Weaknesses