)]}'
{
  "commit": "c19b7d35086b7d240f1ca3088b0079d2bd39ffb9",
  "tree": "8c32548ae448d6b4d4ecabc26f05b56da2f6df41",
  "parents": [
    "c391a40f71886b28c082b47270f0e856fa3e1150"
  ],
  "author": {
    "name": "Eric Dumazet",
    "email": "edumazet@google.com",
    "time": "Thu Sep 10 20:46:11 2026 +0000"
  },
  "committer": {
    "name": "Jakub Kicinski",
    "email": "kuba@kernel.org",
    "time": "Tue Sep 15 17:58:35 2026 -0700"
  },
  "message": "drop_monitor: use raw_cpu_ptr() in tracepoint probes\n\nsyzbot reported a preemption warning in sk_skb_reason_drop():\n\n BUG: using smp_processor_id() in preemptible [00000000] code: syz.0.17/5917\n caller is net_dm_packet_trace_kfree_skb_hit+0x119/0x350 net/core/drop_monitor.c:519\n\nIn net_dm_packet_trace_kfree_skb_hit(), data \u003d this_cpu_ptr(\u0026dm_cpu_data)\nis evaluated before spin_lock_irqsave(\u0026data-\u003edrop_queue.lock, flags).\nWhen kfree_skb() is called from preemptible context (e.g. process context\nduring close() on /dev/net/tun), preemption is enabled, triggering the\nCONFIG_DEBUG_PREEMPT warning in smp_processor_id().\n\nThe same pattern exists in net_dm_hw_trap_summary_probe() and\nnet_dm_hw_trap_packet_probe() for dm_hw_cpu_data.\n\nThis is a false positive because each per-cpu structure is protected\nby its own spinlock. If the task migrates to another CPU right after\nreading the per-cpu pointer, the lock still safely synchronizes\naccess to that queue.\n\nUse raw_cpu_ptr() instead of this_cpu_ptr() to silence\nCONFIG_DEBUG_PREEMPT without disturbing interrupt state or breaking\nPREEMPT_RT locking semantics.\n\nFixes: ca30707dee2b (\"drop_monitor: Add packet alert mode\")\nFixes: 5855357cd40e (\"drop_monitor: Prepare probe functions for devlink tracepoint\")\nReported-by: syzbot+dc57fd6722deb17e92af@syzkaller.appspotmail.com\nCloses: https://lore.kernel.org/netdev/6aa316b2.f81106d8.2ab401.0014.GAE@google.com/\nSigned-off-by: Eric Dumazet \u003cedumazet@google.com\u003e\nLink: https://patch.msgid.link/20260910204612.3762015-4-edumazet@google.com\nSigned-off-by: Jakub Kicinski \u003ckuba@kernel.org\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "873155ca72432924322bb7961996dd3430d052bc",
      "old_mode": 33188,
      "old_path": "net/core/drop_monitor.c",
      "new_id": "795c15dd1771a2a5f15e109d0ef2eed967c45443",
      "new_mode": 33188,
      "new_path": "net/core/drop_monitor.c"
    }
  ]
}