[PATCH v3 4/9] i2c-mlxbf: prevent stack overflow in mlxbf_i2c_smbus_start_transaction()

Asmaa Mnebhi
2022-09-08T17:36:23Z

memcpy() is called in a loop while 'operation->length' upper bound
is not checked and 'data_idx' also increments.

Fixes: b5b5b32081cd206b ("i2c: mlxbf: I2C SMBus driver for Mellanox BlueField SoC")
Reviewed-by: Khalil Blaiech <kblaiech@nvidia.com>
Signed-off-by: Asmaa Mnebhi <asmaa@nvidia.com>
---
drivers/i2c/busses/i2c-mlxbf.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/i2c/busses/i2c-mlxbf.c b/drivers/i2c/busses/i2c-mlxbf.c
index da0bdbd66e2e..a8c5fef3f1cd 100644
--- a/drivers/i2c/busses/i2c-mlxbf.c
+++ b/drivers/i2c/busses/i2c-mlxbf.c
@@ -731,6 +731,9 @@ mlxbf_i2c_smbus_start_transaction(struct mlxbf_i2c_priv *priv,
if (flags & MLXBF_I2C_F_WRITE) {
write_en = 1;
write_len += operation->length;
+ if (data_idx + operation->length >
+ MLXBF_I2C_MASTER_DATA_DESC_SIZE)
+ return -ENOBUFS;
memcpy(data_desc + data_idx,
operation->buffer, operation->length);
data_idx += operation->length;
--
2.30.1