Description
In the Linux kernel, the following vulnerability has been resolved: i2c: rtl9300: ensure data length is within supported range Add an explicit check for the xfer length to 'rtl9300_i2c_config_xfer' to ensure the data length isn't within the supported range. In particular a data length of 0 is not supported by the hardware and causes unintended or destructive behaviour. This limitation becomes obvious when looking at the register documentation [1]. 4 bits are reserved for DATA_WIDTH and the value of these 4 bits is used as N + 1, allowing a data length range of 1 <= len <= 16. Affected by this is the SMBus Quick Operation which works with a data length of 0. Passing 0 as the length causes an underflow of the value due to: (len - 1) & 0xf and effectively specifying a transfer length of 16 via the registers. This causes a 16-byte write operation instead of a Quick Write. For example, on SFP modules without write-protected EEPROM this soft-bricks them by overwriting some initial bytes. For completeness, also add a quirk for the zero length. [1] https://svanheule.net/realtek/longan/register/i2c_mst1_ctrl2
Product status
c366be720235301fdadf67e6f1ea6ff32669c074 before c91382328fc89f73144d5582f2d8f1dd3e41c8f7
c366be720235301fdadf67e6f1ea6ff32669c074 before 06418cb5a1a542a003fdb4ad8e76ea542d57cfba
6.13
Any version before 6.13
6.16.8
6.17
References
git.kernel.org/...c/c91382328fc89f73144d5582f2d8f1dd3e41c8f7
git.kernel.org/...c/06418cb5a1a542a003fdb4ad8e76ea542d57cfba
