From: Dan Carpenter Date: Thu, 15 Sep 2022 11:30:58 +0000 (+0300) Subject: i2c: mux: harden i2c_mux_alloc() against integer overflows X-Git-Tag: v5.19.12~15 X-Git-Url: http://git.itanic.dy.fi/?p=linux-stable;a=commitdiff_plain;h=7f0dcbb0e5576b7a8232306c61334104a822ebf4 i2c: mux: harden i2c_mux_alloc() against integer overflows [ Upstream commit b7af938f4379a884f15713319648a7653497a907 ] 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: 1f3b69b6b939 ("i2c: mux: Use struct_size() in devm_kzalloc()") Signed-off-by: Dan Carpenter Acked-by: Peter Rosin Reviewed-by: Gustavo A. R. Silva Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c index 774507b54b57..313904be5f3b 100644 --- a/drivers/i2c/i2c-mux.c +++ b/drivers/i2c/i2c-mux.c @@ -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)