In the Linux kernel, the following vulnerability has been resolved: tpm: st33zp24: Return zero on status read failure st33zp24_status() ignores the result of the transport read and returns data even when no byte was received

Overview

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

tpm: st33zp24: Return zero on status read failure

st33zp24_status() ignores the result of the transport read and returns data even when no byte was received. The I2C transport, for example, skips i2c_master_recv() when the register-select write is short or fails, leaving data uninitialized. The resulting stack value can be interpreted as TPM_STS flags and let status checks complete spuriously.

The status callback cannot propagate a transport error. Return zero unless recv() reports exactly one byte. With no status bits set, callers retry or take their existing timeout or error path instead of acting on an invalid status value.

This issue was found by a static analysis checker and confirmed by manual source review.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.