On Fri, Jun 14, 2024 at 12:41 PM Florian Westphal <fw@xxxxxxxxx> wrote: > > syzkaller builds (CONFIG_DEBUG_NET=y) frequently trigger a debug > hint in pskb_may_pull. > > We'd like to retain this debug check because it might hint at integer > overflows and other issues (kernel code should pull headers, not huge > value). > > In bpf case, this splat isn't interesting at all: such (nonsensical) bpf > programs are typically generated by a fuzzer anyway. > > Do what Eric suggested and suppress such warning. > > For CONFIG_DEBUG_NET=n we don't need the extra check because > pskb_may_pull will do the right thing: return an error without the > WARN() backtrace. > > Reported-by: syzbot+0c4150bff9fff3bf023c@xxxxxxxxxxxxxxxxxxxxxxxxx > Closes: https://syzkaller.appspot.com/bug?extid=0c4150bff9fff3bf023c > Fixes: 219eee9c0d16 ("net: skbuff: add overflow debug check to pull/push helpers") > Link: https://lore.kernel.org/netdev/9f254c96-54f2-4457-b7ab-1d9f6187939c@xxxxxxxxx/ > Suggested-by: Eric Dumazet <edumazet@xxxxxxxxxx> > Signed-off-by: Florian Westphal <fw@xxxxxxxxx> > --- Thanks Florian Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
