The data->block[0] variable comes from user. Without proper check,
the variable may be very large to cause an out-of-bounds bug.
Fix this bug by checking the value of data->block[0] first.
Similar commit:
1. commit 39244cc7548 ("i2c: ismt: Fix an out-of-bounds bug in
ismt_access()")
2. commit 92fbb6d1296 ("i2c: xgene-slimpro: Fix out-of-bounds
bug in xgene_slimpro_i2c_xfer()")
Signed-off-by: Alex Guo <alexguo1...@gmail.com>
---
drivers/i2c/busses/i2c-powermac.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/i2c/busses/i2c-powermac.c
b/drivers/i2c/busses/i2c-powermac.c
index f99a2cc721a8..3a061b67716a 100644
--- a/drivers/i2c/busses/i2c-powermac.c
+++ b/drivers/i2c/busses/i2c-powermac.c
@@ -78,10 +78,14 @@ static s32 i2c_powermac_smbus_xfer( struct i2c_adapter*
adap,
* anywhere near a pmac i2c bus anyway ...
*/
case I2C_SMBUS_BLOCK_DATA:
+ if (data->block[0] < 1 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
+ return -EINVAL;
buf = data->block;
len = data->block[0] + 1;
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
+ if (data->block[0] < 1 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
+ return -EINVAL;
buf = &data->block[1];
len = data->block[0];
break;
--
2.34.1
