From cffb446e8fd19a14e1634c7a3a8b07be3f01d5c9 Mon Sep 17 00:00:00 2001 From: Bin Meng Date: Wed, 3 Mar 2021 20:26:39 +0800 Subject: [PATCH] hw/sd: sdhci: Reset the data pointer of s->fifo_buffer[] when a different block size is programmed MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit If the block size is programmed to a different value from the previous one, reset the data pointer of s->fifo_buffer[] so that s->fifo_buffer[] can be filled in using the new block size in the next transfer. With this fix, the following reproducer: outl 0xcf8 0x80001010 outl 0xcfc 0xe0000000 outl 0xcf8 0x80001001 outl 0xcfc 0x06000000 write 0xe000002c 0x1 0x05 write 0xe0000005 0x1 0x02 write 0xe0000007 0x1 0x01 write 0xe0000028 0x1 0x10 write 0x0 0x1 0x23 write 0x2 0x1 0x08 write 0xe000000c 0x1 0x01 write 0xe000000e 0x1 0x20 write 0xe000000f 0x1 0x00 write 0xe000000c 0x1 0x32 write 0xe0000004 0x2 0x0200 write 0xe0000028 0x1 0x00 write 0xe0000003 0x1 0x40 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-stable@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 Reported-by: Cornelius Aschermann (Ruhr-Universität Bochum) Reported-by: Sergej Schumilo (Ruhr-Universität Bochum) Reported-by: Simon Wörner (Ruhr-Universität 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 Tested-by: Alexander Bulekov Signed-off-by: Bin Meng Message-Id: <20210303122639.20004-6-bmeng.cn@gmail.com> Signed-off-by: Philippe Mathieu-Daudé CVE: CVE-2021-3409 CVE-2020-17380 Upstream-Status: Backport [import from ubuntu https://git.launchpad.net/ubuntu/+source/qemu/tree/debian/patches/CVE-2021-3409-5.patch?h=ubuntu/focal-security Upstream commit https://github.com/qemu/qemu/commit/cffb446e8fd19a14e1634c7a3a8b07be3f01d5c9 ] Signed-off-by: Chee Yang Lee --- hw/sd/sdhci.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/hw/sd/sdhci.c +++ b/hw/sd/sdhci.c @@ -1135,6 +1135,8 @@ sdhci_write(void *opaque, hwaddr offset, break; case SDHC_BLKSIZE: if (!TRANSFERRING_DATA(s->prnsts)) { + uint16_t blksize = s->blksize; + MASKED_WRITE(s->blksize, mask, extract32(value, 0, 12)); MASKED_WRITE(s->blkcnt, mask >> 16, value >> 16); @@ -1146,6 +1148,16 @@ sdhci_write(void *opaque, hwaddr offset, s->blksize = deposit32(s->blksize, 0, 12, s->buf_maxsz); } + + /* + * If the block size is programmed to a different value from + * the previous one, reset the data pointer of s->fifo_buffer[] + * so that s->fifo_buffer[] can be filled in using the new block + * size in the next transfer. + */ + if (blksize != s->blksize) { + s->data_count = 0; + } } break;