[3.11.y.z extended stable] Patch "Char: ipmi_bt_sm, fix infinite loop" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    Char: ipmi_bt_sm, fix infinite loop

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 936d66d579d8ac4b9b077cd31fa23c5dd77dd2db Mon Sep 17 00:00:00 2001
From: Jiri Slaby <jslaby at suse.cz>
Date: Mon, 14 Apr 2014 09:46:50 -0500
Subject: Char: ipmi_bt_sm, fix infinite loop

commit a94cdd1f4d30f12904ab528152731fb13a812a16 upstream.

In read_all_bytes, we do

  unsigned char i;
  ...
  bt->read_data[0] = BMC2HOST;
  bt->read_count = bt->read_data[0];
  ...
  for (i = 1; i <= bt->read_count; i++)
    bt->read_data[i] = BMC2HOST;

If bt->read_data[0] == bt->read_count == 255, we loop infinitely in the
'for' loop.  Make 'i' an 'int' instead of 'char' to get rid of the
overflow and finish the loop after 255 iterations every time.

Signed-off-by: Jiri Slaby <jslaby at suse.cz>
Reported-and-debugged-by: Rui Hui Dian <rhdian at novell.com>
Cc: Tomas Cech <tcech at suse.cz>
Cc: Corey Minyard <minyard at acm.org>
Cc: <openipmi-developer at lists.sourceforge.net>
Signed-off-by: Corey Minyard <cminyard at mvista.com>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/char/ipmi/ipmi_bt_sm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/char/ipmi/ipmi_bt_sm.c b/drivers/char/ipmi/ipmi_bt_sm.c
index a22a7a5..8156caf 100644
--- a/drivers/char/ipmi/ipmi_bt_sm.c
+++ b/drivers/char/ipmi/ipmi_bt_sm.c
@@ -352,7 +352,7 @@ static inline void write_all_bytes(struct si_sm_data *bt)

 static inline int read_all_bytes(struct si_sm_data *bt)
 {
-	unsigned char i;
+	unsigned int i;

 	/*
 	 * length is "framing info", minimum = 4: NetFn, Seq, Cmd, cCode.
--
1.9.1