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

mtd: fix double free and WARN_ON in add_mtd_device() error paths

When device_register() or mtd_nvmem_add() fails inside
add_mtd_device() for a partition, the error handling triggers
mtd_release() via put_device() or device_unregister(). mtd_release()
calls release_mtd_partition() which frees the mtd_info structure.
However, callers such as mtd_add_partition() and add_mtd_partitions()
also call free_partition() in their error paths, resulting in a double
free.

Additionally, release_mtd_partition() hits WARN_ON(!list_empty(
&mtd->part.node)) because the partition node is still linked in the
parent's partitions list when the release callback fires from the
add_mtd_device() error path.

Fix this by overriding dev->type and dev->release before put_device()
in the error paths, so that device_release() invokes a no-op function
instead of mtd_release(). For the mtd_nvmem_add() failure case,
device_unregister() is replaced with device_del() to separate the
device removal from the final kobject reference drop, allowing the
override to take effect before put_device() is called.

The callers' error paths (list_del + free_partition) remain the sole
owners of mtd_info lifetime on add_mtd_device() failure, which is the
expected contract.

The normal partition teardown path is not affected: del_mtd_device()
goes through kref_put() -> mtd_device_release() -> device_unregister()
with dev->type still set to &mtd_devtype, so mtd_release() ->
release_mtd_partition() continues to work correctly for the regular
removal case.

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Mon, 10 Aug 2026 16:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-415

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

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: mtd: fix double free and WARN_ON in add_mtd_device() error paths When device_register() or mtd_nvmem_add() fails inside add_mtd_device() for a partition, the error handling triggers mtd_release() via put_device() or device_unregister(). mtd_release() calls release_mtd_partition() which frees the mtd_info structure. However, callers such as mtd_add_partition() and add_mtd_partitions() also call free_partition() in their error paths, resulting in a double free. Additionally, release_mtd_partition() hits WARN_ON(!list_empty( &mtd->part.node)) because the partition node is still linked in the parent's partitions list when the release callback fires from the add_mtd_device() error path. Fix this by overriding dev->type and dev->release before put_device() in the error paths, so that device_release() invokes a no-op function instead of mtd_release(). For the mtd_nvmem_add() failure case, device_unregister() is replaced with device_del() to separate the device removal from the final kobject reference drop, allowing the override to take effect before put_device() is called. The callers' error paths (list_del + free_partition) remain the sole owners of mtd_info lifetime on add_mtd_device() failure, which is the expected contract. The normal partition teardown path is not affected: del_mtd_device() goes through kref_put() -> mtd_device_release() -> device_unregister() with dev->type still set to &mtd_devtype, so mtd_release() -> release_mtd_partition() continues to work correctly for the regular removal case.
Title mtd: fix double free and WARN_ON in add_mtd_device() error paths
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-10T12:04:36.582Z

Reserved: 2026-07-30T09:28:09.391Z

Link: CVE-2026-68416

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-10T16:15:04Z

Weaknesses