Hello,
An infinite loop issue in hw/net/eepro100.c emulator was reported by Mr
Qinghao Tang(CC'd here).
Below is a proposed fix patch and details about the issue.
===
From f06497dfefabbdd6f966a5d6c177d85cd0e5ecd8 Mon Sep 17 00:00:00 2001
From: Prasad J Pandit <p...@fedoraproject.org>
Date: Fri, 16 Oct 2015 11:33:27 +0530
Subject: eepro100: prevent an infinite loop over same command block
action_command() routine executes a chain of commands located
in the Command Block List(CBL). Each Command Block(CB) has a
link to the next CB in the list, given by 's->tx.link'.
This is used in conjunction with the base address 's->cu_base'.
An infinite loop unfolds if the 'link' to the next CB is
same as the previous one, the loop ends up executing the same
command over and over again.
Reported-by: Qinghao Tang <luodalon...@gmail.com>
Signed-off-by: Prasad J Pandit <p...@fedoraproject.org>
---
hw/net/eepro100.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/hw/net/eepro100.c b/hw/net/eepro100.c
index 60333b7..d76d108 100644
--- a/hw/net/eepro100.c
+++ b/hw/net/eepro100.c
@@ -863,6 +863,8 @@ static void action_command(EEPRO100State *s)
uint16_t ok_status = STATUS_OK;
s->cb_address = s->cu_base + s->cu_offset;
read_cb(s);
+ if (s->tx.link == s->cu_offset)
+ break;
bit_el = ((s->tx.command & COMMAND_EL) != 0);
bit_s = ((s->tx.command & COMMAND_S) != 0);
bit_i = ((s->tx.command & COMMAND_I) != 0);
--
2.4.3
===
Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
47AF CE69 3A90 54AA 9045 1053 DD13 3D32 FE5B 041F
