On Mon, 2017-08-14 at 21:31 +0200, Paolo Abeni wrote: > From: Al Viro <v...@zeniv.linux.org.uk> > > copy_linear_skb() is broken; both of its callers actually > expect 'len' to be the amount we are trying to copy, > not the offset of the end. > Fix it keeping the meanings of arguments in sync with what the > callers (both of them) expect. > Also restore a saner behavior on EFAULT (i.e. preserving > the iov_iter position in case of failure): > > The commit fd851ba9caa9 ("udp: harden copy_linear_skb()") > avoids the more destructive effect of the buggy > copy_linear_skb(), e.g. no more invalid memory access, but > said function still behaves incorrectly: when peeking with > offset it can fail with EINVAL instead of copying the > appropriate amount of memory. > > Reported-by: Sasha Levin <alexander.le...@verizon.com> > Fixes: b65ac44674dd ("udp: try to avoid 2 cache miss on dequeue") > Fixes: fd851ba9caa9 ("udp: harden copy_linear_skb()") > Signed-off-by: Al Viro <v...@zeniv.linux.org.uk> > Acked-by: Paolo Abeni <pab...@redhat.com> > Tested-by: Sasha Levin <alexander.le...@verizon.com> > ---
Oh well. Acked-by: Eric Dumazet <eduma...@google.com>