commit cee271678d0e3177a25d0fcb2fa5e051d48e4262
author Björn Töpel <bjorn.topel@intel.com> Mon Oct 08 19:40:16 2018 +0200
committer Daniel Borkmann <daniel@iogearbox.net> Thu Oct 11 10:19:01 2018 +0200
tree b63781801b81ccc68cda0d24417764e90ec138c1
parent 262f9d811c7608f1e74258ceecfe1fa213bdf912

xsk: do not call synchronize_net() under RCU read lock

The XSKMAP update and delete functions called synchronize_net(), which
can sleep. It is not allowed to sleep during an RCU read section.

Instead we need to make sure that the sock sk_destruct (xsk_destruct)
function is asynchronously called after an RCU grace period. Setting
the SOCK_RCU_FREE flag for XDP sockets takes care of this.

Fixes: fbfc504a24f5 ("bpf: introduce new bpf AF_XDP map type BPF_MAP_TYPE_XSKMAP")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>