openbsd-ports/emulators/qemu/patches/patch-hw_block_fdc_c
sthen 78402cc18f Security fixes for qemu, from brad:
CVE-2015-3456  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.


CVE-2015-3209  pcnet: force the buffer access to be in bounds during tx

4096 is the maximum length per TMD and it is also currently the size of
the relay buffer pcnet driver uses for sending the packet data to QEMU
for further processing. With packet spanning multiple TMDs it can
happen that the overall packet size will be bigger than sizeof(buffer),
which results in memory corruption.

Fix this by only allowing to queue maximum sizeof(buffer) bytes.
2015-07-18 20:36:56 +00:00

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$OpenBSD: patch-hw_block_fdc_c,v 1.1 2015/07/18 20:36:57 sthen Exp $
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.
CVE-2015-3456
--- hw/block/fdc.c.orig Tue Jul 14 19:14:04 2015
+++ hw/block/fdc.c Tue Jul 14 19:18:07 2015
@@ -1512,7 +1512,7 @@ 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;
@@ -1521,8 +1521,8 @@ 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)) {
@@ -1867,10 +1867,13 @@ static void fdctrl_handle_option(FDCtrl *fdctrl, int d
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;
@@ -1970,7 +1973,7 @@ 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)) {
@@ -2019,7 +2022,9 @@ static void fdctrl_write_data(FDCtrl *fdctrl, uint32_t
}
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