[PATCH] i2c: Several PEC-related fixes in software SMBus emulation

Fix several errors in I2C SMBus emulation when PEC is used:
* Weird logic error in SMBus Write Word transactions.
* Wrong buffer size, affecting SMBus Block Write transactions.
* Potential buffer overrun in SMBus Block Write transactions.

From: Hideki Iwamoto <h-iwamoto@kit.hi-ho.ne.jp>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
 drivers/i2c/i2c-core.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index b55097d57b7a995bfc48b33d3a374cec0503680d..9583a54ce16baf18531713543dd5eab5ca628a05 100644 (file)
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -864,7 +864,7 @@ static int i2c_smbus_add_pec(u16 addr, u8 command, int size,
                        break;
                case I2C_SMBUS_BYTE_DATA:
                        buf[2] = data->byte;
-                       data->word = buf[2] ||
+                       data->word = buf[2] |
                                    (i2c_smbus_pec(3, buf, NULL) << 8);
                        size = I2C_SMBUS_WORD_DATA;
                        break;
@@ -1033,8 +1033,8 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
          need to use only one message; when reading, we need two. We initialize
          most things with sane defaults, to keep the code below somewhat
          simpler. */
-       unsigned char msgbuf0[34];
-       unsigned char msgbuf1[34];
+       unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3];
+       unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2];
        int num = read_write == I2C_SMBUS_READ?2:1;
        struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 }, 
                                  { addr, flags | I2C_M_RD, 0, msgbuf1 }
@@ -1097,7 +1097,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
                        }
                        if(size == I2C_SMBUS_BLOCK_DATA_PEC)
                                (msg[0].len)++;
-                       for (i = 1; i <= msg[0].len; i++)
+                       for (i = 1; i < msg[0].len; i++)
                                msgbuf0[i] = data->block[i-1];
                }
                break;