CVE-2024-53085: 
Linux Kernel vulnerability analysis and mitigation

CVE-2024-53085 affects the Linux kernel's TPM (Trusted Platform Module) driver implementation. The vulnerability was discovered in the tpmpmsuspend() function where setting TPMCHIPFLAGSUSPENDED at the end of the function can lead to a race condition. This allows tpmhwrng_read() to be called while the operation is in progress. The vulnerability affects Linux kernel versions from 6.4 up to (excluding) 6.11.8 (NVD).

The vulnerability stems from a race condition in the TPM driver's suspend functionality. The issue occurs because TPMCHIPFLAGSUSPENDED is set at the end of tpmpmsuspend(), leaving a window where tpmhwrng_read() can be called during the suspension process. The CVSS v3.1 base score is 5.5 (MEDIUM) with vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. The vulnerability is classified as CWE-667: Improper Locking (NVD, Kernel Patch).

The vulnerability can lead to undefined behavior when the TPM chip is being suspended while random number generation operations are in progress. This could potentially result in system instability or denial of service conditions during system suspend operations (Kernel Patch).

The issue has been fixed by modifying the locking mechanism in the TPM driver. The fix involves locking the TPM chip before checking any chip->flags in both tpmpmsuspend() and tpmhwrngread() functions, and moving the TPMCHIPFLAGSUSPENDED check inside tpmget_random(). Users should update to kernel version 6.11.8 or later to receive the fix (Kernel Patch).