In the Linux kernel, the following vulnerability has been resolved:
bpf: Reject BPF_MAP_TYPE_INODE_STORAGE creation if BPF LSM is uninitialized
When CONFIG_BPF_LSM=y is set, BPF inode storage maps
(BPF_MAP_TYPE_INODE_STORAGE) are compiled into the kernel. However,
if the BPF LSM is not explicitly enabled at boot time (e.g. omitted
from the "lsm=" boot parameter), lsm_prepare() is never executed for
the BPF LSM.
Consequently, the BPF inode security blob offset
(bpf_lsm_blob_sizes.lbs_inode) is never initialized and remains at
its default compiled size of 8 bytes instead of being updated to a
valid offset past the reserved struct rcu_head (typically 16 bytes
or more).
When a privileged user creates and updates a BPF_MAP_TYPE_INODE_STORAGE
map, bpf_inode() evaluates inode->i_security + 8. This erroneously
aliases the struct rcu_head.func callback pointer at the beginning
of the inode->i_security blob. During subsequent map element cleanup
or inode destruction, writing NULL to owner_storage clears the queued
RCU callback pointer. When rcu_do_batch() later executes the queued
callback, it attempts an instruction fetch at address 0x0, triggering
an immediate kernel panic.
Fix this by introducing a global bpf_lsm_initialized boolean flag
marked with __ro_after_init. Set this flag to true inside bpf_lsm_init()
when the LSM framework successfully registers the BPF LSM. Gate map
allocation in inode_storage_map_alloc() on this flag, returning
-EOPNOTSUPP if the BPF LSM is in turn uninitialized.
This fail-fast approach prevents userspace from allocating inode
storage maps when the supporting BPF LSM infrastructure is absent,
avoiding zombie map states.
Metrics
Affected Vendors & Products
| Vendors | Products |
|---|---|
| Linux |
|
No data.
No data.
OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.
| Vendors | Products |
|---|---|
| Linux |
|
References
History
Mon, 20 Jul 2026 16:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: bpf: Reject BPF_MAP_TYPE_INODE_STORAGE creation if BPF LSM is uninitialized When CONFIG_BPF_LSM=y is set, BPF inode storage maps (BPF_MAP_TYPE_INODE_STORAGE) are compiled into the kernel. However, if the BPF LSM is not explicitly enabled at boot time (e.g. omitted from the "lsm=" boot parameter), lsm_prepare() is never executed for the BPF LSM. Consequently, the BPF inode security blob offset (bpf_lsm_blob_sizes.lbs_inode) is never initialized and remains at its default compiled size of 8 bytes instead of being updated to a valid offset past the reserved struct rcu_head (typically 16 bytes or more). When a privileged user creates and updates a BPF_MAP_TYPE_INODE_STORAGE map, bpf_inode() evaluates inode->i_security + 8. This erroneously aliases the struct rcu_head.func callback pointer at the beginning of the inode->i_security blob. During subsequent map element cleanup or inode destruction, writing NULL to owner_storage clears the queued RCU callback pointer. When rcu_do_batch() later executes the queued callback, it attempts an instruction fetch at address 0x0, triggering an immediate kernel panic. Fix this by introducing a global bpf_lsm_initialized boolean flag marked with __ro_after_init. Set this flag to true inside bpf_lsm_init() when the LSM framework successfully registers the BPF LSM. Gate map allocation in inode_storage_map_alloc() on this flag, returning -EOPNOTSUPP if the BPF LSM is in turn uninitialized. This fail-fast approach prevents userspace from allocating inode storage maps when the supporting BPF LSM infrastructure is absent, avoiding zombie map states. | |
| Title | bpf: Reject BPF_MAP_TYPE_INODE_STORAGE creation if BPF LSM is uninitialized | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-07-20T16:27:51.720Z
Reserved: 2026-07-19T07:54:57.040Z
Link: CVE-2026-64192
Vulnrichment
No data.
NVD
No data.
Redhat
No data.
OpenCVE Enrichment
Updated: 2026-07-20T23:45:04Z