File 0120-ppc-pnv-check-size-before-data-buff.patch of Package qemu-testsuite.20749

From: Prasad J Pandit <pjp@fedoraproject.org>
Date: Fri, 26 Oct 2018 18:03:58 +0530
Subject: ppc/pnv: check size before data buffer access
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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 d07945e78eb6b593cd17a4640c1fc9eb35e3245d)
[BR: BSC#1114957 CVE-2018-18954]
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 hw/ppc/pnv_lpc.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/hw/ppc/pnv_lpc.c b/hw/ppc/pnv_lpc.c
index f03a80a29bf638df3b3132a1aee1..a0505e636217f09c0aaa48ff3360 100644
--- a/hw/ppc/pnv_lpc.c
+++ b/hw/ppc/pnv_lpc.c
@@ -161,9 +161,15 @@ 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) {