Commit b7af938f authored by Dan Carpenter's avatar Dan Carpenter Committed by Wolfram Sang
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i2c: mux: harden i2c_mux_alloc() against integer overflows 



A couple years back we went through the kernel an automatically
converted size calculations to use struct_size() instead.  The
struct_size() calculation is protected against integer overflows.

However it does not make sense to use the result from struct_size()
for additional math operations as that would negate any safeness.

Fixes: 1f3b69b6 ("i2c: mux: Use struct_size() in devm_kzalloc()")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Acked-by: default avatarPeter Rosin <peda@axentia.se>
Reviewed-by: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
parent 37f071ec

drivers/i2c/i2c-mux.c

+3 −2
Original line number Diff line number Diff line
@@ -243,9 +243,10 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent, 
				   int (*deselect)(struct i2c_mux_core *, u32))

{

	struct i2c_mux_core *muxc;

	size_t mux_size;



	muxc = devm_kzalloc(dev, struct_size(muxc, adapter, max_adapters)

			    + sizeof_priv, GFP_KERNEL);

	mux_size = struct_size(muxc, adapter, max_adapters);

	muxc = devm_kzalloc(dev, size_add(mux_size, sizeof_priv), GFP_KERNEL);

	if (!muxc)

		return NULL;

	if (sizeof_priv)