From db916870a839346767b6d5ca7d0eed3128ba5fea Mon Sep 17 00:00:00 2001 From: Bin Meng Date: Wed, 3 Mar 2021 20:26:39 +0800 Subject: [PATCH 6/6] 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=UTF-8 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 Upstream-Status: Backport [cffb446e8fd19a14e1634c7a3a8b07be3f01d5c9] CVE: CVE-2021-3409 Signed-off-by: Sakib Sajal --- hw/sd/sdhci.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c index 6c780126e..216842420 100644 --- a/hw/sd/sdhci.c +++ b/hw/sd/sdhci.c @@ -1140,6 +1140,8 @@ sdhci_write(void *opaque, hwaddr offset, uint64_t val, unsigned size) 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); @@ -1151,6 +1153,16 @@ sdhci_write(void *opaque, hwaddr offset, uint64_t val, unsigned size) 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; -- 2.29.2