CVE-2021-3409

The patch for CVE-2020-17380 and CVE-2020-25085, both involving a heap buffer overflow in the SDHCI controller emulation code of QEMU, was found to be incomplete. A malicious privileged guest could reproduce the same issues with specially crafted input, inducing a bogus transfer and subsequent out-of-bounds read/write access in sdhci_do_adma() or sdhci_sdma_transfer_multi_blocks(). CVE-2021-3409 was assigned to facilitate the tracking and backporting of the new patch.