qemu-all: fix CVE-2015-3456

3 files changed, 87 insertions, 2 deletions

diff --git a/qemu-all/.md5sum b/qemu-all/.md5sum
index acbd37d55..b711d543d 100644
--- a/qemu-all/.md5sum
+++ b/qemu-all/.md5sum
@@ -1 +1,2 @@
+d2ec15ed5ad82e6bf0eb90bb9c27b656  CVE-3456.diff
 2fab3ea4460de9b57192e5b8b311f221  qemu-2.3.0.tar.bz2
diff --git a/qemu-all/CVE-3456.diff b/qemu-all/CVE-3456.diff
new file mode 100644
index 000000000..2844caa4d
--- /dev/null
+++ b/qemu-all/CVE-3456.diff
@@ -0,0 +1,81 @@
+From: Petr Matousek <pmatouse@redhat.com>
+Date: Wed, 6 May 2015 07:48:59 +0000 (+0200)
+Subject: fdc: force the fifo access to be in bounds of the allocated buffer
+X-Git-Url: http://git.qemu.org/?p=qemu.git;a=commitdiff_plain;h=e907746266721f305d67bc0718795fedee2e824c
+
+fdc: force the fifo access to be in bounds of the allocated buffer
+
+During processing of certain commands such as FD_CMD_READ_ID and
+FD_CMD_DRIVE_SPECIFICATION_COMMAND the fifo memory access could
+get out of bounds leading to memory corruption with values coming
+from the guest.
+
+Fix this by making sure that the index is always bounded by the
+allocated memory.
+
+This is CVE-2015-3456.
+
+Signed-off-by: Petr Matousek <pmatouse@redhat.com>
+Reviewed-by: John Snow <jsnow@redhat.com>
+Signed-off-by: John Snow <jsnow@redhat.com>
+---
+
+diff --git a/hw/block/fdc.c b/hw/block/fdc.c
+index f72a392..d8a8edd 100644
+--- a/hw/block/fdc.c
++++ b/hw/block/fdc.c
+@@ -1497,7 +1497,7 @@ static uint32_t fdctrl_read_data(FDCtrl *fdctrl)
+ {
+     FDrive *cur_drv;
+     uint32_t retval = 0;
+-    int pos;
++    uint32_t pos;
+ 
+     cur_drv = get_cur_drv(fdctrl);
+     fdctrl->dsr &= ~FD_DSR_PWRDOWN;
+@@ -1506,8 +1506,8 @@ static uint32_t fdctrl_read_data(FDCtrl *fdctrl)
+         return 0;
+     }
+     pos = fdctrl->data_pos;
++    pos %= FD_SECTOR_LEN;
+     if (fdctrl->msr & FD_MSR_NONDMA) {
+-        pos %= FD_SECTOR_LEN;
+         if (pos == 0) {
+             if (fdctrl->data_pos != 0)
+                 if (!fdctrl_seek_to_next_sect(fdctrl, cur_drv)) {
+@@ -1852,10 +1852,13 @@ static void fdctrl_handle_option(FDCtrl *fdctrl, int direction)
+ static void fdctrl_handle_drive_specification_command(FDCtrl *fdctrl, int direction)
+ {
+     FDrive *cur_drv = get_cur_drv(fdctrl);
++    uint32_t pos;
+ 
+-    if (fdctrl->fifo[fdctrl->data_pos - 1] & 0x80) {
++    pos = fdctrl->data_pos - 1;
++    pos %= FD_SECTOR_LEN;
++    if (fdctrl->fifo[pos] & 0x80) {
+         /* Command parameters done */
+-        if (fdctrl->fifo[fdctrl->data_pos - 1] & 0x40) {
++        if (fdctrl->fifo[pos] & 0x40) {
+             fdctrl->fifo[0] = fdctrl->fifo[1];
+             fdctrl->fifo[2] = 0;
+             fdctrl->fifo[3] = 0;
+@@ -1955,7 +1958,7 @@ static uint8_t command_to_handler[256];
+ static void fdctrl_write_data(FDCtrl *fdctrl, uint32_t value)
+ {
+     FDrive *cur_drv;
+-    int pos;
++    uint32_t pos;
+ 
+     /* Reset mode */
+     if (!(fdctrl->dor & FD_DOR_nRESET)) {
+@@ -2004,7 +2007,9 @@ static void fdctrl_write_data(FDCtrl *fdctrl, uint32_t value)
+     }
+ 
+     FLOPPY_DPRINTF("%s: %02x\n", __func__, value);
+-    fdctrl->fifo[fdctrl->data_pos++] = value;
++    pos = fdctrl->data_pos++;
++    pos %= FD_SECTOR_LEN;
++    fdctrl->fifo[pos] = value;
+     if (fdctrl->data_pos == fdctrl->data_len) {
+         /* We now have all parameters
+          * and will be able to treat the command
diff --git a/qemu-all/Pkgfile b/qemu-all/Pkgfile
index f63aa83ff..48ab6e500 100644
--- a/qemu-all/Pkgfile
+++ b/qemu-all/Pkgfile
@@ -7,12 +7,15 @@
  
 name=qemu-all
 version=2.3.0
-release=1
-source=(http://wiki.qemu.org/download/qemu-$version.tar.bz2)
+release=2
+source=(http://wiki.qemu.org/download/qemu-$version.tar.bz2
+        CVE-3456.diff)
 
 build() {
 
   cd qemu-$version
+  
+  patch -p1 -i $SRC/CVE-3456.diff
 
   ./configure --prefix=/usr \
       --cc="${CC:=gcc}" \