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authorP J P <pjp@fedoraproject.org>2015-09-15 16:40:49 +0530
committerStefan Hajnoczi <stefanha@redhat.com>2015-09-15 12:51:14 +0100
commit9bbdbc66e5765068dce76e9269dce4547afd8ad4 (patch)
treebe69a5ef5c32570fe2bdabac54ff824580a65208 /hw/net/ne2000.c
parentb947ac2bf26479e710489739c465c8af336599e7 (diff)
net: add checks to validate ring buffer pointers(CVE-2015-5279)
Ne2000 NIC uses ring buffer of NE2000_MEM_SIZE(49152) bytes to process network packets. While receiving packets via ne2000_receive() routine, a local 'index' variable could exceed the ring buffer size, which could lead to a memory buffer overflow. Added other checks at initialisation. Reported-by: Qinghao Tang <luodalongde@gmail.com> Signed-off-by: P J P <pjp@fedoraproject.org> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'hw/net/ne2000.c')
-rw-r--r--hw/net/ne2000.c19
1 files changed, 15 insertions, 4 deletions
diff --git a/hw/net/ne2000.c b/hw/net/ne2000.c
index 53c704ad41..3798a3b2f2 100644
--- a/hw/net/ne2000.c
+++ b/hw/net/ne2000.c
@@ -221,6 +221,9 @@ ssize_t ne2000_receive(NetClientState *nc, const uint8_t *buf, size_t size_)
}
index = s->curpag << 8;
+ if (index >= NE2000_PMEM_END) {
+ index = s->start;
+ }
/* 4 bytes for header */
total_len = size + 4;
/* address for next packet (4 bytes for CRC) */
@@ -306,13 +309,19 @@ static void ne2000_ioport_write(void *opaque, uint32_t addr, uint32_t val)
offset = addr | (page << 4);
switch(offset) {
case EN0_STARTPG:
- s->start = val << 8;
+ if (val << 8 <= NE2000_PMEM_END) {
+ s->start = val << 8;
+ }
break;
case EN0_STOPPG:
- s->stop = val << 8;
+ if (val << 8 <= NE2000_PMEM_END) {
+ s->stop = val << 8;
+ }
break;
case EN0_BOUNDARY:
- s->boundary = val;
+ if (val << 8 < NE2000_PMEM_END) {
+ s->boundary = val;
+ }
break;
case EN0_IMR:
s->imr = val;
@@ -353,7 +362,9 @@ static void ne2000_ioport_write(void *opaque, uint32_t addr, uint32_t val)
s->phys[offset - EN1_PHYS] = val;
break;
case EN1_CURPAG:
- s->curpag = val;
+ if (val << 8 < NE2000_PMEM_END) {
+ s->curpag = val;
+ }
break;
case EN1_MULT ... EN1_MULT + 7:
s->mult[offset - EN1_MULT] = val;