ppc/pnv: check size before data buffer access

While performing PowerNV memory r/w operations, the access length
'sz' could exceed the data[4] buffer size. Add check to avoid OOB
access.

Reported-by: Moguofang <moguofang@huawei.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
(cherry picked from commit d07945e78e)
*CVE-2018-18954
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
stable-3.0
Prasad J Pandit 2018-10-26 18:03:58 +05:30 committed by Michael Roth
parent 345fab6ffe
commit 8d25276172
1 changed files with 7 additions and 1 deletions

View File

@ -155,9 +155,15 @@ static void pnv_lpc_do_eccb(PnvLpcController *lpc, uint64_t cmd)
/* XXX Check for magic bits at the top, addr size etc... */
unsigned int sz = (cmd & ECCB_CTL_SZ_MASK) >> ECCB_CTL_SZ_LSH;
uint32_t opb_addr = cmd & ECCB_CTL_ADDR_MASK;
uint8_t data[4];
uint8_t data[8];
bool success;
if (sz > sizeof(data)) {
qemu_log_mask(LOG_GUEST_ERROR,
"ECCB: invalid operation at @0x%08x size %d\n", opb_addr, sz);
return;
}
if (cmd & ECCB_CTL_READ) {
success = opb_read(lpc, opb_addr, data, sz);
if (success) {