From: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> Date: Tue, 6 Aug 2019 16:16:40 +0200 > In 'st_nci_i2c_read()', we allocate a sk_buff with a size of > ST_NCI_I2C_MIN_SIZE + len. > > However, later on, we first 'skb_reserve()' ST_NCI_I2C_MIN_SIZE bytes, then > we 'skb_put()' ST_NCI_I2C_MIN_SIZE bytes. > Finally, if 'len' is not 0, we 'skb_put()' 'len' bytes. > > So we use ST_NCI_I2C_MIN_SIZE*2 + len bytes. > > This is incorrect and should already panic. I guess that it does not occur > because of extra memory allocated because of some rounding. > > Fix it and allocate enough room for the 'skb_reserve()' and the 'skb_put()' > calls. > > Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> > --- > This patch is LIKELY INCORRECT. So think twice to what is the correct > solution before applying it. > Maybe the skb_reserve should be axed or some other sizes are incorrect. > There seems to be an issue, that's all I can say. The skb_reserve() should be removed, and the second memcpy() should remove the " + ST_NCI_I2C_MIN_SIZE". This SKB just get sent down to ndlc_recv() so the content returned from I2C should places at skb->data to be processed. Pretty clear this code was never tested.
