CVE-2026-23353

In the Linux kernel, the following vulnerability has been resolved:

ice: fix crash in ethtool offline loopback test

Since the conversion of ice to page pool, the ethtool loopback test
crashes:

 BUG: kernel NULL pointer dereference, address: 000000000000000c
 #PF: supervisor write access in kernel mode
 #PF: error_code(0x0002) - not-present page
 PGD 1100f1067 P4D 0
 Oops: Oops: 0002 [#1] SMP NOPTI
 CPU: 23 UID: 0 PID: 5904 Comm: ethtool Kdump: loaded Not tainted 6.19.0-0.rc7.260128g1f97d9dcf5364.49.eln154.x86_64 #1 PREEMPT(lazy)
 Hardware name: [...]
 RIP: 0010:ice_alloc_rx_bufs+0x1cd/0x310 [ice]
 Code: 83 6c 24 30 01 66 41 89 47 08 0f 84 c0 00 00 00 41 0f b7 dc 48 8b 44 24 18 48 c1 e3 04 41 bb 00 10 00 00 48 8d 2c 18 8b 04 24 <89> 45 0c 41 8b 4d 00 49 d3 e3 44 3b 5c 24 24 0f 83 ac fe ff ff 44
 RSP: 0018:ff7894738aa1f768 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: 0000000000000700 RDI: 0000000000000000
 RBP: 0000000000000000 R08: ff16dcae79880200 R09: 0000000000000019
 R10: 0000000000000001 R11: 0000000000001000 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: ff16dcae6c670000
 FS:  00007fcf428850c0(0000) GS:ff16dcb149710000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000000000000000c CR3: 0000000121227005 CR4: 0000000000773ef0
 PKRU: 55555554
 Call Trace:
  <TASK>
  ice_vsi_cfg_rxq+0xca/0x460 [ice]
  ice_vsi_cfg_rxqs+0x54/0x70 [ice]
  ice_loopback_test+0xa9/0x520 [ice]
  ice_self_test+0x1b9/0x280 [ice]
  ethtool_self_test+0xe5/0x200
  __dev_ethtool+0x1106/0x1a90
  dev_ethtool+0xbe/0x1a0
  dev_ioctl+0x258/0x4c0
  sock_do_ioctl+0xe3/0x130
  __x64_sys_ioctl+0xb9/0x100
  do_syscall_64+0x7c/0x700
  entry_SYSCALL_64_after_hwframe+0x76/0x7e
  [...]

It crashes because we have not initialized libeth for the rx ring.

Fix it by treating ICE_VSI_LB VSIs slightly more like normal PF VSIs and
letting them have a q_vector. It's just a dummy, because the loopback
test does not use interrupts, but it contains a napi struct that can be
passed to libeth_rx_fq_create() called from ice_vsi_cfg_rxq() ->
ice_rxq_pp_create().