In the Linux kernel, the following vulnerability has been resolved: Input: rmi_smbus - fix out-of-bounds read in rmi_smb_write_block() When chunking writes into SMBus blocks in rmi_smb_write_block(), the loop calculates block_len using…

Overview

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

Input: rmi_smbus - fix out-of-bounds read in rmi_smb_write_block()

When chunking writes into SMBus blocks in rmi_smb_write_block(), the loop calculates block_len using the original total length (len) instead of the remaining length (cur_len).

If len is greater than 32 bytes (SMB_MAX_COUNT), block_len remains 32 for every iteration, even on the final partial chunk where fewer than 32 bytes remain. This causes smb_block_write() to read 32 bytes from the advanced data buffer pointer, reading past the end of the input buffer.

Fix this by calculating block_len using cur_len and advancing the buffer and address pointers by block_len.

Remediation

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