[PATCH 3.4 21/27] Char: ipmi_bt_sm, fix infinite loop

Greg Kroah-Hartman
2014-04-24T22:08:58Z

From: Jiri Slaby <jslaby@suse.cz>

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@suse.cz>
Reported-and-debugged-by: Rui Hui Dian <rhdian@novell.com>
Cc: Tomas Cech <tcech@suse.cz>
Cc: Corey Minyard <minyard@acm.org>
Cc: <openipmi-developer@lists.sourceforge.net>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/char/ipmi/ipmi_bt_sm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- 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(struc

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.