CVE-2025-68773: spi: fsl-cpm: Check length parity before switching to 16 bit mode
In the Linux kernel, the following vulnerability has been resolved:
spi: fsl-cpm: Check length parity before switching to 16 bit mode
Commit fc96ec826bce ("spi: fsl-cpm: Use 16 bit mode for large transfers with even size") failed to make sure that the size is really even before switching to 16 bit mode. Until recently the problem went unnoticed because kernfs uses a pre-allocated bounce buffer of size PAGESIZE for reading EEPROM.
But commit 8ad6249c51d0 ("eeprom: at25: convert to spi-mem API") introduced an additional dynamically allocated bounce buffer whose size is exactly the size of the transfer, leading to a buffer overrun in the fsl-cpm driver when that size is odd.
Add the missing length parity verification and remain in 8 bit mode when the length is not even.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
Apply the fix from commit fc96ec826bce by ensuring the spi: fsl-cpm driver “Check length parity before switching to 16 bit mode” so the transfer size is really even before moving out of 8 bit mode.
Event History
Frequently Asked Questions
What is the severity of CVE-2025-68773?
CVE-2025-68773 is classified as a high-severity vulnerability due to its potential impact on data integrity.
How do I fix CVE-2025-68773?
To fix CVE-2025-68773, it is recommended to update to the patched version of the Linux kernel that addresses this vulnerability.
What systems are affected by CVE-2025-68773?
CVE-2025-68773 affects various versions of the Linux kernel that utilizes the fsl-cpm SPI driver.
What are the consequences of not addressing CVE-2025-68773?
Failing to address CVE-2025-68773 may allow attackers to exploit the vulnerability, potentially leading to data corruption during SPI transactions.
How does CVE-2025-68773 impact SPI communication?
CVE-2025-68773 can introduce issues during 16-bit mode switching in SPI communication, particularly with large data transfers.