Per "SD Host Controller Standard Specification Version 7.00" chapter 2.2.1 SDMA System Address Register:
This register can be accessed only if no transaction is executing (i.e., after a transaction has stopped). With this fix, the following reproducer: https://paste.debian.net/plain/1185137 cannot be reproduced with the following QEMU command line: $ qemu-system-x86_64 -nographic -machine accel=qtest -m 512M \ -nodefaults -device sdhci-pci,sd-spec-version=3 \ -drive if=sd,index=0,file=null-co://,format=raw,id=mydrive \ -device sd-card,drive=mydrive -qtest stdio Cc: qemu-sta...@nongnu.org Fixes: CVE-2020-17380 Fixes: CVE-2020-25085 Fixes: CVE-2021-3409 Fixes: d7dfca0807a0 ("hw/sdhci: introduce standard SD host controller") Reported-by: Alexander Bulekov <alx...@bu.edu> Reported-by: Cornelius Aschermann (Ruhr-University Bochum) Reported-by: Muhammad Ramdhan Reported-by: Sergej Schumilo (Ruhr-University Bochum) Reported-by: Simon Wrner (Ruhr-University Bochum) Buglink: https://bugs.launchpad.net/qemu/+bug/1892960 Buglink: https://bugs.launchpad.net/qemu/+bug/1909418 Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1928146 Signed-off-by: Bin Meng <bmeng...@gmail.com> --- (no changes since v1) hw/sd/sdhci.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c index 1c5ab26..05cb281 100644 --- a/hw/sd/sdhci.c +++ b/hw/sd/sdhci.c @@ -1122,15 +1122,17 @@ sdhci_write(void *opaque, hwaddr offset, uint64_t val, unsigned size) switch (offset & ~0x3) { case SDHC_SYSAD: - s->sdmasysad = (s->sdmasysad & mask) | value; - MASKED_WRITE(s->sdmasysad, mask, value); - /* Writing to last byte of sdmasysad might trigger transfer */ - if (!(mask & 0xFF000000) && TRANSFERRING_DATA(s->prnsts) && s->blkcnt && - s->blksize && SDHC_DMA_TYPE(s->hostctl1) == SDHC_CTRL_SDMA) { - if (s->trnmod & SDHC_TRNS_MULTI) { - sdhci_sdma_transfer_multi_blocks(s); - } else { - sdhci_sdma_transfer_single_block(s); + if (!TRANSFERRING_DATA(s->prnsts)) { + s->sdmasysad = (s->sdmasysad & mask) | value; + MASKED_WRITE(s->sdmasysad, mask, value); + /* Writing to last byte of sdmasysad might trigger transfer */ + if (!(mask & 0xFF000000) && s->blkcnt && s->blksize && + SDHC_DMA_TYPE(s->hostctl1) == SDHC_CTRL_SDMA) { + if (s->trnmod & SDHC_TRNS_MULTI) { + sdhci_sdma_transfer_multi_blocks(s); + } else { + sdhci_sdma_transfer_single_block(s); + } } } break; -- 2.7.4
