drivers/char/ipmi: memcpy, need additional 2 bytes to avoid memory overflow

When calling memcpy, read_data and write_data need additional 2 bytes.

  write_data:
    for checking:  "if (size > IPMI_MAX_MSG_LENGTH)"
    for operating: "memcpy(bt->write_data + 3, data + 1, size - 1)"

  read_data:
    for checking:  "if (msg_len < 3 || msg_len > IPMI_MAX_MSG_LENGTH)"
    for operating: "memcpy(data + 2, bt->read_data + 4, msg_len - 2)"

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/char/ipmi/ipmi_bt_sm.c b/drivers/char/ipmi/ipmi_bt_sm.c
index cdd4c09fda96..a22a7a502740 100644
--- a/drivers/char/ipmi/ipmi_bt_sm.c
+++ b/drivers/char/ipmi/ipmi_bt_sm.c
@@ -95,9 +95,9 @@ struct si_sm_data {
         enum bt_states  state;
         unsigned char   seq;            /* BT sequence number */
         struct si_sm_io *io;
-        unsigned char   write_data[IPMI_MAX_MSG_LENGTH];
+        unsigned char   write_data[IPMI_MAX_MSG_LENGTH + 2]; /* +2 for memcpy */
         int             write_count;
-        unsigned char   read_data[IPMI_MAX_MSG_LENGTH];
+        unsigned char   read_data[IPMI_MAX_MSG_LENGTH + 2]; /* +2 for memcpy */
         int             read_count;
         int             truncated;
         long            timeout;        /* microseconds countdown */