CVE-2026-98207

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

mmc: spi: reset bytes_xfered before retrying CRC failures

mmc_spi_data_do() updates data->bytes_xfered after each block has been

transferred successfully. If a later block in the same data request

fails with a CRC error, data->bytes_xfered may therefore contain the

number of bytes completed before the failing block.

mmc_spi_request() has a private recovery path for such CRC failures. It

sends STOP_TRANSMISSION, clears data->error and jumps back to

crc_recover to issue the same command and data request again. However,

it does not clear data->bytes_xfered before the retry.

If the retry succeeds, the request is completed with the bytes from the

failed attempt still included in data->bytes_xfered. For a multi-block

request this can make the completed request report more bytes than were

transferred by the successful retry, and can even exceed the request size

when most blocks completed before the CRC error.

This is most likely to be observed on MMC-over-SPI systems where long

multi-block transfers occasionally hit a data CRC error but the

mmc_spi-internal retry succeeds. The data itself is retried, but the

completion accounting is not.

Clear data->bytes_xfered together with data->error before repeating the

request so the final completion reports only the bytes transferred by the

successful attempt.