| From 00837731d254908a841d69298a4f9f077babaf24 Mon Sep 17 00:00:00 2001 |
| From: Stefan Weil <sw@weilnetz.de> |
| Date: Fri, 20 Nov 2015 08:42:33 +0100 |
| Subject: [PATCH] eepro100: Prevent two endless loops |
| |
| http://lists.nongnu.org/archive/html/qemu-devel/2015-11/msg04592.html |
| shows an example how an endless loop in function action_command can |
| be achieved. |
| |
| During my code review, I noticed a 2nd case which can result in an |
| endless loop. |
| |
| Reported-by: Qinghao Tang <luodalongde@gmail.com> |
| Signed-off-by: Stefan Weil <sw@weilnetz.de> |
| Signed-off-by: Jason Wang <jasowang@redhat.com> |
| |
| Upstream-Status: Backport |
| |
| http://git.qemu.org/?p=qemu.git;a=commit;h=00837731d254908a841d69298a4f9f077babaf24 |
| |
| CVE: CVE-2015-8345 |
| [Yocto # 9013] |
| |
| Signed-off-by: Armin Kuster <akuster@mvista.com> |
| |
| --- |
| hw/net/eepro100.c | 16 ++++++++++++++++ |
| 1 file changed, 16 insertions(+) |
| |
| diff --git a/hw/net/eepro100.c b/hw/net/eepro100.c |
| index 60333b7..685a478 100644 |
| --- a/hw/net/eepro100.c |
| +++ b/hw/net/eepro100.c |
| @@ -774,6 +774,11 @@ static void tx_command(EEPRO100State *s) |
| #if 0 |
| uint16_t tx_buffer_el = lduw_le_pci_dma(&s->dev, tbd_address + 6); |
| #endif |
| + if (tx_buffer_size == 0) { |
| + /* Prevent an endless loop. */ |
| + logout("loop in %s:%u\n", __FILE__, __LINE__); |
| + break; |
| + } |
| tbd_address += 8; |
| TRACE(RXTX, logout |
| ("TBD (simplified mode): buffer address 0x%08x, size 0x%04x\n", |
| @@ -855,6 +860,10 @@ static void set_multicast_list(EEPRO100State *s) |
| |
| static void action_command(EEPRO100State *s) |
| { |
| + /* The loop below won't stop if it gets special handcrafted data. |
| + Therefore we limit the number of iterations. */ |
| + unsigned max_loop_count = 16; |
| + |
| for (;;) { |
| bool bit_el; |
| bool bit_s; |
| @@ -870,6 +879,13 @@ static void action_command(EEPRO100State *s) |
| #if 0 |
| bool bit_sf = ((s->tx.command & COMMAND_SF) != 0); |
| #endif |
| + |
| + if (max_loop_count-- == 0) { |
| + /* Prevent an endless loop. */ |
| + logout("loop in %s:%u\n", __FILE__, __LINE__); |
| + break; |
| + } |
| + |
| s->cu_offset = s->tx.link; |
| TRACE(OTHER, |
| logout("val=(cu start), status=0x%04x, command=0x%04x, link=0x%08x\n", |
| -- |
| 2.3.5 |
| |