From dfba99f17feb6d4a129da19d38df1bcd8579d1c3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Tue, 1 Sep 2020 15:22:06 +0200 Subject: [PATCH] hw/sd/sdhci: Fix DMA Transfer Block Size field MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The 'Transfer Block Size' field is 12-bit wide. See section '2.2.2. Block Size Register (Offset 004h)' in datasheet. Two different bug reproducer available: - https://bugs.launchpad.net/qemu/+bug/1892960 - https://ruhr-uni-bochum.sciebo.de/s/NNWP2GfwzYKeKwE?path=%2Fsdhci_oob_write1 Cc: qemu-stable@nongnu.org Buglink: https://bugs.launchpad.net/qemu/+bug/1892960 Fixes: d7dfca0807a ("hw/sdhci: introduce standard SD host controller") Reported-by: Alexander Bulekov Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Prasad J Pandit Tested-by: Alexander Bulekov Message-Id: <20200901140411.112150-3-f4bug@amsat.org> Upstream-Status: Backport CVE: CVE-2020-25085 Signed-off-by: Armin Kuster --- hw/sd/sdhci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: qemu-4.2.0/hw/sd/sdhci.c =================================================================== --- qemu-4.2.0.orig/hw/sd/sdhci.c +++ qemu-4.2.0/hw/sd/sdhci.c @@ -1129,7 +1129,7 @@ sdhci_write(void *opaque, hwaddr offset, break; case SDHC_BLKSIZE: if (!TRANSFERRING_DATA(s->prnsts)) { - MASKED_WRITE(s->blksize, mask, value); + MASKED_WRITE(s->blksize, mask, extract32(value, 0, 12)); MASKED_WRITE(s->blkcnt, mask >> 16, value >> 16); }