In the Linux kernel, the following vulnerability has been resolved:
virtionet: Fix napiskbcacheput warning
After the commit bdacf3e34945 ("net: Use nested-BH locking for napialloccache.") was merged, the following warning began to appear:
 WARNING: CPU: 5 PID: 1 at net/core/skbuff.c:1451 napi_skb_cache_put+0x82/0x4b0
  __warn+0x12f/0x340
  napi_skb_cache_put+0x82/0x4b0
  napi_skb_cache_put+0x82/0x4b0
  report_bug+0x165/0x370
  handle_bug+0x3d/0x80
  exc_invalid_op+0x1a/0x50
  asm_exc_invalid_op+0x1a/0x20
  __free_old_xmit+0x1c8/0x510
  napi_skb_cache_put+0x82/0x4b0
  __free_old_xmit+0x1c8/0x510
  __free_old_xmit+0x1c8/0x510
  __pfx___free_old_xmit+0x10/0x10
The issue arises because virtio is assuming it's running in NAPI context even when it's not, such as in the netpoll case.
To resolve this, modify virtnetpolltx() to only set NAPI when budget is available. Same for virtnetpollcleantx(), which always assumed that it was in a NAPI context.