In one embodiment, a processor includes a memory hierarchy and a core coupled to the memory hierarchy. The memory hierarchy stores encrypted data, and the core includes circuitry to access the encrypted data stored in the memory hierarchy, decrypt the encrypted data to yield decrypted data, perform an entropy test on the decrypted data, and update a processor state based on a result of the entropy test. The entropy test may include determining a number of data entities in the decrypted data whose values are equal to one another, determining a number of adjacent data entities in the decrypted data whose values are equal to one another, determining a number of data entities in the decrypted data whose values are equal to at least one special value from a set of special values, or determining a sum of n highest data entity value frequencies.

A method for authorizing I/O (input/output) commands in a storage cluster is provided. The method includes generating a token responsive to an authority initiating an I/O command, wherein the token is specific to assignment of the authority and a storage node of the storage cluster. The method includes verifying the I/O command using the token, wherein the token includes a signature confirming validity of the token and wherein the token is revocable.

An apparatus includes a processor, configured to designate a memory region in a memory, and to issue (i) memory-access commands for accessing the memory and (ii) a conditional-fence command associated with the designated memory region. Memory-Access Control Circuitry (MACC) is configured, in response to identifying the conditional-fence command, to allow execution of the memory-access commands that access addresses within the designated memory region, and to defer the execution of the memory-access commands that access addresses outside the designated memory region, until completion of all the memory-access commands that were issued before the conditional-fence command.

A single input/output (I/O) controller for both secure partitionable endpoints (PEs) and non-secure PEs is enabled in a trusted execution environment (TEE) where secure memory portions are isolated from non-secure PEs. Security attributes for certain endpoints indicate secure memory access privilege of owning entities of the certain endpoints. A security monitor has exclusive access to the address translation control tables (TCE) stored in secure memory associated with a secure endpoint. When owning entity reassignment occurs, the endpoints are reinitialized to support a change in ownership from an outgoing owning entity having secure memory access and an incoming owning entity not having secure memory access.

A compute instance is instrumented to detect certain kernel memory allocation functions, in particular functions that allocate heap memory and/or make allocated memory executable. Dynamic shell code exploits can then be detected when code executing from heap memory allocates additional heap memory and makes that additional heap memory executable.

Techniques are described for metadata processing that can be used to encode an arbitrary number of security policies for code running on a processor. Metadata may be added to every word in the system and a metadata processing unit may be used that works in parallel with data flow to enforce an arbitrary set of policies. In one aspect, the metadata may be characterized as unbounded and software programmable to be applicable to a wide range of metadata processing policies. Techniques and policies have a wide range of uses including, for example, safety, security, and synchronization. Additionally, described are aspects and techniques in connection with metadata processing in an embodiment based on the RISC-V architecture.

In one embodiment, an encoded pointer is constructed from a stack pointer that includes offset. The encoded pointer includes the offset value and ciphertext that is based on encrypting a portion of a decorated pointer that includes a maximum offset value. Stack data is encrypted based on the encoded pointer, and the encoded pointer is stored in a stack pointer register of a processor. To access memory, a decoded pointer is constructed based on decrypting the ciphertext of the encoded pointer and the offset value. Encrypted stack data is accessed based on the decoded pointer, and the encrypted stack is decrypted based on the encoded pointer.

An apparatus has tag checking circuitry responsive to a target address to: identify a guard tag stored in a memory system in association with a block of one or more memory locations, the block containing a target memory location identified by the target address, perform a tag check based on the guard tag and an address tag associated with the target address, and in response to detecting a mismatch in the tag check, perform an error response action. The apparatus also has tag mapping storage circuitry to store mapping information indicative of a mapping between guard tag values and corresponding address tag values. The tag checking circuitry remaps at least one of the guard tag and the address tag based on the mapping information stored by the tag mapping storage circuitry to generate a remapped tag for use in the tag check.

An example memory subsystem includes a memory component and a processing device, operatively coupled to the memory component. The processing device is configured to receive a plurality of logical-to-physical (L2P) records, wherein an L2P record of the plurality of L2P records maps a logical block address to a physical address of a memory block on the memory component; determine a sequential assist value specifying a number of logical block addresses that are mapped to consecutive physical addresses sequentially following the physical address specified by the L2P record; generate a security token encoding the sequential assist value; and associate the security token with the L2P record.

Memory devices, systems including memory devices, and methods of operating memory devices are described, in which security measures may be implemented to control access to a fuse array (or other secure features) of the memory devices based on a secure access key. In some cases, a customer may define and store a user-defined access key in the fuse array. In other cases, a manufacturer of the memory device may define a manufacturer-defined access key (e.g., an access key based on fuse identification (FID), a secret access key), where a host device coupled with the memory device may obtain the manufacturer-defined access key according to certain protocols. The memory device may compare an access key included in a command directed to the memory device with either the user-defined access key or the manufacturer-defined access key to determine whether to permit or prohibit execution of the command based on the comparison.