In the Linux kernel, the following vulnerability has been resolved:
keys: make keyring indexes independent of kernel addresses
KEYCTL_READ returns the serial numbers in a keyring in associative-array
traversal order. The first word of the index is a public, deterministic
hash of the type pointer, domain pointer and description. An unprivileged
user can therefore insert keys with known descriptions, predict their
order for each possible KASLR slide, and recover the kernel image address.
On an x86-64 build with 16 MiB alignment, 45 user keys suffice to
distinguish the candidate slides.
Remove the addresses from the whole index, not just its first hash word.
Assign each key type and domain a nonzero 64-bit ID and hash those IDs and
the description with a once-initialized SipHash key. Use the full IDs in
the later index chunks as well. Truncating or hashing the IDs there would
lose the guarantee that distinct type/domain/description tuples have a
differing index bit.
Allocate IDs lazily since private key types need not be registered. Cache
them in the index key so tree walks and copies of an existing index do not
need to dereference a type descriptor that may have been unregistered.
Keep the 32-bit chunk layout and diff_objects() bit offsets consistent,
and retain the separate root slot for keyrings used by recursive search.
The key comparison, permissions and userspace data format are unchanged;
only the address-dependent in-memory ordering is replaced.
keys: make keyring indexes independent of kernel addresses
KEYCTL_READ returns the serial numbers in a keyring in associative-array
traversal order. The first word of the index is a public, deterministic
hash of the type pointer, domain pointer and description. An unprivileged
user can therefore insert keys with known descriptions, predict their
order for each possible KASLR slide, and recover the kernel image address.
On an x86-64 build with 16 MiB alignment, 45 user keys suffice to
distinguish the candidate slides.
Remove the addresses from the whole index, not just its first hash word.
Assign each key type and domain a nonzero 64-bit ID and hash those IDs and
the description with a once-initialized SipHash key. Use the full IDs in
the later index chunks as well. Truncating or hashing the IDs there would
lose the guarantee that distinct type/domain/description tuples have a
differing index bit.
Allocate IDs lazily since private key types need not be registered. Cache
them in the index key so tree walks and copies of an existing index do not
need to dereference a type descriptor that may have been unregistered.
Keep the 32-bit chunk layout and diff_objects() bit offsets consistent,
and retain the separate root slot for keyrings used by recursive search.
The key comparison, permissions and userspace data format are unchanged;
only the address-dependent in-memory ordering is replaced.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Mon, 02 Nov 2026 16:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: keys: make keyring indexes independent of kernel addresses KEYCTL_READ returns the serial numbers in a keyring in associative-array traversal order. The first word of the index is a public, deterministic hash of the type pointer, domain pointer and description. An unprivileged user can therefore insert keys with known descriptions, predict their order for each possible KASLR slide, and recover the kernel image address. On an x86-64 build with 16 MiB alignment, 45 user keys suffice to distinguish the candidate slides. Remove the addresses from the whole index, not just its first hash word. Assign each key type and domain a nonzero 64-bit ID and hash those IDs and the description with a once-initialized SipHash key. Use the full IDs in the later index chunks as well. Truncating or hashing the IDs there would lose the guarantee that distinct type/domain/description tuples have a differing index bit. Allocate IDs lazily since private key types need not be registered. Cache them in the index key so tree walks and copies of an existing index do not need to dereference a type descriptor that may have been unregistered. Keep the 32-bit chunk layout and diff_objects() bit offsets consistent, and retain the separate root slot for keyrings used by recursive search. The key comparison, permissions and userspace data format are unchanged; only the address-dependent in-memory ordering is replaced. | |
| Title | keys: make keyring indexes independent of kernel addresses | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-11-02T16:06:33.408Z
Reserved: 2026-09-25T10:25:14.402Z
Link: CVE-2026-99223
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-11-02T16:17:46.650
Modified: 2026-11-02T16:17:46.650
Link: CVE-2026-99223
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.