CVE-2022-48806 Information

Description

In the Linux kernel the following vulnerability has been resolved:

eeprom: ee1004: limit i2c reads to I2C_SMBUS_BLOCK_MAX

Commit effa453168a7 (\i2c: i801: Don’t silently correct invalid transfer size) revealed that ee1004_eeprom_read() did not properly limit how many bytes to read at once.

In particular i2c_smbus_read_i2c_block_data_or_emulated() takes the length to read as an u8. If count == 256 after taking into account the offset and page boundary the cast to u8 overflows. And this is common when user space tries to read the entire EEPROM at once.

To fix it limit each read to I2C_SMBUS_BLOCK_MAX (32) bytes already the maximum length i2c_smbus_read_i2c_block_data_or_emulated() allows.

Reference

https://git.kernel.org/stable/c/3937c35493ee2847aaefcfa5460e94b7443eef49 https://git.kernel.org/stable/c/a37960df7eac3cc8094bd1ab84864e9e32c91345 https://git.kernel.org/stable/c/9a5f471ae380f9fcb9756d453c12ca1f8595a93c https://git.kernel.org/stable/c/9443ddeb3754e9e382a396b50adc1961301713ce https://git.kernel.org/stable/c/c0689e46be23160d925dca95dfc411f1a0462708