i2c: mlxbf: prevent stack overflow in mlxbf_i2c_smbus_start_transaction()

[ Upstream commit de24aceb07d426b6f1c59f33889d6a964770547b ]

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>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/i2c/busses/i2c-mlxbf.c b/drivers/i2c/busses/i2c-mlxbf.c
index 612736906440d5e8dd08176a8b02f94f3b5aaaa4..ac93c0ccf53c541811e424aa6e8ed6b0d94b9e28 100644 (file)
--- a/drivers/i2c/busses/i2c-mlxbf.c
+++ b/drivers/i2c/busses/i2c-mlxbf.c
@@ -738,6 +738,9 @@ 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;