releases/5.0.15/i3c-fix-a-shift-wrap-bug-in-i3c_bus_set_addr_slot_status.patch

   1 From 476c7e1d34f2a03b1aa5a924c50703053fe5f77c Mon Sep 17 00:00:00 2001
   2 From: Dan Carpenter <dan.carpenter@oracle.com>
   3 Date: Tue, 23 Apr 2019 13:40:20 +0300
   4 Subject: i3c: Fix a shift wrap bug in i3c_bus_set_addr_slot_status()
   5
   6 From: Dan Carpenter <dan.carpenter@oracle.com>
   7
   8 commit 476c7e1d34f2a03b1aa5a924c50703053fe5f77c upstream.
   9
  10 The problem here is that addr can be I3C_BROADCAST_ADDR (126).  That
  11 means we're shifting by (126 * 2) % 64 which is 60.  The
  12 I3C_ADDR_SLOT_STATUS_MASK is an enum which is an unsigned int in GCC
  13 so shifts greater than 31 are undefined.
  14
  15 Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure")
  16 Cc: <stable@vger.kernel.org>
  17 Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
  18 Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
  19 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  20
  21 ---
  22  drivers/i3c/master.c |    5 +++--
  23  1 file changed, 3 insertions(+), 2 deletions(-)
  24
  25 --- a/drivers/i3c/master.c
  26 +++ b/drivers/i3c/master.c
  27 @@ -385,8 +385,9 @@ static void i3c_bus_set_addr_slot_status
  28                 return;
  29
  30         ptr = bus->addrslots + (bitpos / BITS_PER_LONG);
  31 -       *ptr &= ~(I3C_ADDR_SLOT_STATUS_MASK << (bitpos % BITS_PER_LONG));
  32 -       *ptr |= status << (bitpos % BITS_PER_LONG);
  33 +       *ptr &= ~((unsigned long)I3C_ADDR_SLOT_STATUS_MASK <<
  34 +                                               (bitpos % BITS_PER_LONG));
  35 +       *ptr |= (unsigned long)status << (bitpos % BITS_PER_LONG);
  36  }
  37
  38  static bool i3c_bus_dev_addr_is_avail(struct i3c_bus *bus, u8 addr)