On Thu, Jan 7, 2021 at 3:53 PM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > On Thu, 7 Jan 2021 11:47:02 -0800 > Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > > On Wed, Jan 6, 2021 at 8:45 PM Willem de Bruijn <willemb@xxxxxxxxxx> wrote: > > > > > > But there are three other kmap_atomic callers under net/ that do not > > > loop at all, so assume non-compound pages. In esp_output_head, > > > esp6_output_head and skb_seq_read. The first two directly use > > > skb_page_frag_refill, which can allocate compound (but not > > > __GFP_HIGHMEM) pages, and the third can be inserted with > > > netfilter xt_string in the path of tcp transmit skbs, which can also > > > have compound pages. I think that these could similarly access > > > data beyond the end of the kmap_atomic mapped page. I'll take > > > a closer look. > > > > Thanks. > > > > Note that I have flushed my random one-liner patch from my system, and > > expect to get a proper fix through the normal networking pulls. > > > > And _if_ the networking people feel that my one-liner was the proper > > fix, you can use it and add my sign-off if you want to, but it really > > was more of a "this is the quick ugly fix for testing" rather than > > anything else. I do think it is the proper fix as is. If no one else has comments, I can submit it through the net tree. It won't address the other issues that became apparent only as a result of this. I'm preparing separate patches for those. > Please add: > > Link: https://lore.kernel.org/linux-mm/20210106180132.41dc249d@xxxxxxxxxxxxxxxxxx/ > Reported-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> > > And if you take Linus's patch, please add my: > > Tested-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> > > and if you come up with another patch, please send it to me for testing. > > Thanks! Will do, thanks.
