CVE-2026-98207

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux061c6c847eeb11743e489a16e907b41c6f9042b6 < 7d2f0ec16b300645f20435a6c3827b15e01419afaffected
LinuxLinux061c6c847eeb11743e489a16e907b41c6f9042b6 < d1acf4b9f6e9697406ce84ee9acfb92e094d5c7aaffected
LinuxLinux061c6c847eeb11743e489a16e907b41c6f9042b6 < 0b8c8504593409954ed1a60db4e437d814e04023affected
LinuxLinux061c6c847eeb11743e489a16e907b41c6f9042b6 < da4929ee78ee701c3717543840798fedff66c430affected
LinuxLinux061c6c847eeb11743e489a16e907b41c6f9042b6 < 57f5e29db63f7c80f1805d89234a74dcdbf60231affected
LinuxLinux061c6c847eeb11743e489a16e907b41c6f9042b6 < 4885e587f1afa9e1a573ab66f8c4d94d7b836d86affected
LinuxLinux061c6c847eeb11743e489a16e907b41c6f9042b6 < 3ae80c1fb7de4d3331427a955a44807745ac5a33affected
LinuxLinux061c6c847eeb11743e489a16e907b41c6f9042b6 < 8b0cc8707f65e0f51912e764e1b309b2559db1ecaffected
LinuxLinux2.6.37affected
LinuxLinux0 < 2.6.37unaffected
LinuxLinux5.10.271 <= 5.10.*unaffected
LinuxLinux5.15.222 <= 5.15.*unaffected
LinuxLinux6.1.189 <= 6.1.*unaffected
LinuxLinux6.6.158 <= 6.6.*unaffected
LinuxLinux6.12.112 <= 6.12.*unaffected
LinuxLinux6.18.54 <= 6.18.*unaffected
LinuxLinux7.2.8 <= 7.2.*unaffected
LinuxLinux7.3-rc4 <= *unaffected

Weaknesses

References