diff options
Diffstat (limited to 'xsa133-qemuu.patch')
| -rw-r--r-- | xsa133-qemuu.patch | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/xsa133-qemuu.patch b/xsa133-qemuu.patch new file mode 100644 index 000000000000..95f3dcc21e5b --- /dev/null +++ b/xsa133-qemuu.patch @@ -0,0 +1,84 @@ +From ac7ddbe342d7aa2303c39ca731cc6229dbbd739b Mon Sep 17 00:00:00 2001 +From: Petr Matousek <pmatouse@redhat.com> +Date: Wed, 6 May 2015 09:48:59 +0200 +Subject: [PATCH] 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> +--- + hw/block/fdc.c | 17 +++++++++++------ + 1 file changed, 11 insertions(+), 6 deletions(-) + +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 +-- +2.1.0 + + |