Reformulate bpf_dettachd() to acquire the BIF_LOCK() as well as

BPFD_LOCK() when removing a descriptor from an interface descriptor
list.  Hold both over the operation, and do a better job at
maintaining the invariant that you can't find partially connected
descriptors on an active interface descriptor list.

This appears to close a race that resulted in the kernel performing
a NULL pointer dereference when BPF sessions are detached during
heavy network activity on SMP systems.

RELENG_5 candidate.

0 files changed, 0 insertions, 0 deletions