6ae81ced3788 ("af_packet: tone down the Tx-ring unsupported spew.")

[Zubin Mithra <zsm@xxxxxxxxxxxx>]

Hello,

Syzkaller has triggered a WARNING in packet_set_ring when fuzzing a 4.4 kernel with the following stacktrace.
Call Trace:
  __dump_stack lib/dump_stack.c:15 [inline]
  dump_stack+0xc1/0x124 lib/dump_stack.c:51
  panic+0x1a7/0x351 kernel/panic.c:115
  warn_slowpath_common+0x12a/0x140 kernel/panic.c:463
  warn_slowpath_fmt+0xb0/0xe0 kernel/panic.c:479
  packet_set_ring+0x13ed/0x19c0 net/packet/af_packet.c:4104
  packet_setsockopt+0x53e/0x21d0 net/packet/af_packet.c:3578
  SYSC_setsockopt net/socket.c:1766 [inline]
  SyS_setsockopt+0x15d/0x240 net/socket.c:1745
  entry_SYSCALL_64_fastpath+0x12/0x72


Could the following patch be applied in v4.4.y? It is present in v4.9.y. Applying this patch could
allow the fuzzer to explore more codepaths.
* 6ae81ced3788 ("af_packet: tone down the Tx-ring unsupported spew.")


Thanks,
- Zubin