Linux Kernel Keyring Index Leak Exposes KASLR Address
CVE-2026-99223 Published on November 2, 2026
keys: make keyring indexes independent of kernel addresses
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.
Products Associated with CVE-2026-99223
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Affected Versions
Linux:- Version b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 and below 9ebe824d55983c9f063a2c9ef1a08b29812d406f is affected.
- Version b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 and below e108b22999edbc6f431466baf6b2016c19b7ed31 is affected.
- Version b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 and below 9f084ef0beb68091e96ab96f0e95579aac8a77f9 is affected.
- Version b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 and below 8451d4a4c43127c3b9fdf9fc9ff3fea5539a61f9 is affected.
- Version b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 and below 13fc051269d670810d9e314061b61c6dd06116a0 is affected.
- Version b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 and below 61ac0585d9f4344d3dfb84b5edff1fee7d532897 is affected.
- Version b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 and below 84f7c699f8d139f743c7dc11ef41d085690955bb is affected.
- Version b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 and below a113eba06bd1183c614d7994864d6e7054140cb9 is affected.
- Version 3.13 is affected.
- Before 3.13 is unaffected.
- Version 5.10.273, <= 5.10.* is unaffected.
- Version 5.15.224, <= 5.15.* is unaffected.
- Version 6.1.191, <= 6.1.* is unaffected.
- Version 6.6.161, <= 6.6.* is unaffected.
- Version 6.12.115, <= 6.12.* is unaffected.
- Version 6.18.60, <= 6.18.* is unaffected.
- Version 7.2.14, <= 7.2.* is unaffected.
- Version 7.3.1, <= 7.3.* is unaffected.