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

mtd: core: Fix refcount error in del_mtd_device()

del_mtd_device() will call of_node_put() to mtd_get_of_node(mtd), which
is mtd->dev.of_node. However, memset(&mtd->dev, 0) is called before
of_node_put(). As the result, of_node_put() won't do anything in
del_mtd_device(), and causes the refcount leak.

del_mtd_device()
memset(&mtd->dev, 0, sizeof(mtd->dev) # clear mtd->dev
of_node_put()
mtd_get_of_node(mtd) # mtd->dev is cleared, can't locate of_node
# of_node_put(NULL) won't do anything

Fix the error by caching the pointer of the device_node.

OF: ERROR: memory leak, expected refcount 1 instead of 2,
of_node_get()/of_node_put() unbalanced - destroy cset entry: attach
overlay node /spi/spi-sram@0
CPU: 3 PID: 275 Comm: python3 Tainted: G N 6.1.0-rc3+ #54
0d8a1edddf51f172ff5226989a7565c6313b08e2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x67/0x83
kobject_get+0x155/0x160
of_node_get+0x1f/0x30
of_fwnode_get+0x43/0x70
fwnode_handle_get+0x54/0x80
fwnode_get_nth_parent+0xc9/0xe0
fwnode_full_name_string+0x3f/0xa0
device_node_string+0x30f/0x750
pointer+0x598/0x7a0
vsnprintf+0x62d/0x9b0
...
cfs_overlay_release+0x30/0x90
config_item_release+0xbe/0x1a0
config_item_put+0x5e/0x80
configfs_rmdir+0x3bd/0x540
vfs_rmdir+0x18c/0x320
do_rmdir+0x198/0x330
__x64_sys_rmdir+0x2c/0x40
do_syscall_64+0x37/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd

[<miquel.raynal@bootlin.com>: Light reword of the commit log]
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 02 Oct 2025 09:00:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel

Thu, 02 Oct 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low


Wed, 01 Oct 2025 12:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: mtd: core: Fix refcount error in del_mtd_device() del_mtd_device() will call of_node_put() to mtd_get_of_node(mtd), which is mtd->dev.of_node. However, memset(&mtd->dev, 0) is called before of_node_put(). As the result, of_node_put() won't do anything in del_mtd_device(), and causes the refcount leak. del_mtd_device() memset(&mtd->dev, 0, sizeof(mtd->dev) # clear mtd->dev of_node_put() mtd_get_of_node(mtd) # mtd->dev is cleared, can't locate of_node # of_node_put(NULL) won't do anything Fix the error by caching the pointer of the device_node. OF: ERROR: memory leak, expected refcount 1 instead of 2, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node /spi/spi-sram@0 CPU: 3 PID: 275 Comm: python3 Tainted: G N 6.1.0-rc3+ #54 0d8a1edddf51f172ff5226989a7565c6313b08e2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x67/0x83 kobject_get+0x155/0x160 of_node_get+0x1f/0x30 of_fwnode_get+0x43/0x70 fwnode_handle_get+0x54/0x80 fwnode_get_nth_parent+0xc9/0xe0 fwnode_full_name_string+0x3f/0xa0 device_node_string+0x30f/0x750 pointer+0x598/0x7a0 vsnprintf+0x62d/0x9b0 ... cfs_overlay_release+0x30/0x90 config_item_release+0xbe/0x1a0 config_item_put+0x5e/0x80 configfs_rmdir+0x3bd/0x540 vfs_rmdir+0x18c/0x320 do_rmdir+0x198/0x330 __x64_sys_rmdir+0x2c/0x40 do_syscall_64+0x37/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd [<miquel.raynal@bootlin.com>: Light reword of the commit log]
Title mtd: core: Fix refcount error in del_mtd_device()
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-10-01T11:45:30.263Z

Reserved: 2025-10-01T11:38:45.640Z

Link: CVE-2022-50457

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-10-01T12:15:38.967

Modified: 2025-10-01T12:15:38.967

Link: CVE-2022-50457

cve-icon Redhat

Severity : Low

Publid Date: 2025-10-01T00:00:00Z

Links: CVE-2022-50457 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-10-02T08:38:39Z