| Message ID | 20190423104020.GA3133@mwanda (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 476c7e1d34f2a03b1aa5a924c50703053fe5f77c |
| Headers | show |
| Series | i3c: Fix a shift wrap bug in i3c_bus_set_addr_slot_status() | expand |
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index 1412abcff010..5f4bd52121fe 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -385,8 +385,9 @@ static void i3c_bus_set_addr_slot_status(struct i3c_bus *bus, u16 addr, return; ptr = bus->addrslots + (bitpos / BITS_PER_LONG); - *ptr &= ~(I3C_ADDR_SLOT_STATUS_MASK << (bitpos % BITS_PER_LONG)); - *ptr |= status << (bitpos % BITS_PER_LONG); + *ptr &= ~((unsigned long)I3C_ADDR_SLOT_STATUS_MASK << + (bitpos % BITS_PER_LONG)); + *ptr |= (unsigned long)status << (bitpos % BITS_PER_LONG); } static bool i3c_bus_dev_addr_is_avail(struct i3c_bus *bus, u8 addr)
The problem here is that addr can be I3C_BROADCAST_ADDR (126). That means we're shifting by (126 * 2) % 64 which is 60. The I3C_ADDR_SLOT_STATUS_MASK is an enum which is an unsigned int in GCC so shifts greater than 31 are undefined. Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- This patch is from static analysis. I really know what *ptr is used for and I haven't tested the code. The other question is would be testing this code on 32 bit systems. Please review carefully. drivers/i3c/master.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)