On 19.10.2020 04:54, Jia-Ju Bai wrote: > In rtl8180_tx(), skb->data is mapped to streaming DMA on line 476: > mapping = dma_map_single(..., skb->data, ...); > > On line 459, skb->data is assigned to hdr after cast: > struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; > > Then hdr->seq_ctrl is accessed on lines 540 and 541: > hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG); > hdr->seq_ctrl |= cpu_to_le16(priv->seqno); > > These DMA accesses may cause data inconsistency between CPU and hardwre. > > To fix this problem, hdr->seq_ctrl is accessed before the DMA mapping. > This looks like a bug fix to me, shouldn't this have a Fixes: tag and be CC'ed to stable@? Maciej
