We are seeing a WARN due to local_bh_disable called with interrupts disabled with CONFIG_IRQSOFF_TRACER / CONFIG_PREEMPT_TRACER. Here is the WARN trace 1833.210427: <6> Call trace: 1833.212833: <2> [<ffffffc000088530>] dump_backtrace+0x0/0x270 1833.212838: <2> [<ffffffc0000887b0>] show_stack+0x10/0x1c 1833.212853: <2> [<ffffffc000c6edac>] dump_stack+0x74/0xb8 1833.212862: <2> [<ffffffc0000a0fe4>] warn_slowpath_common+0x88/0xb0 1833.212865: <2> [<ffffffc0000a10d0>] warn_slowpath_null+0x14/0x20 1833.212870: <2> [<ffffffc0000a46dc>] __local_bh_disable_ip+0x4c/0xc8 1833.212882: <2> [<ffffffc000ae2788>] destroy_conntrack+0x90/0x184 1833.212888: <2> [<ffffffc000adcd50>] nf_conntrack_destroy+0x28/0x38 1833.212896: <2> [<ffffffc000a97550>] skb_release_head_state+0xa4/0xe0 1833.212900: <2> [<ffffffc000a977e0>] __kfree_skb+0x10/0xbc 1833.212904: <2> [<ffffffc000a976bc>] kfree_skb+0xb4/0xdc 1833.212912: <2> [<ffffffc000aa4660>] flush_backlog+0x88/0x120 1833.212922: <2> [<ffffffc00010e544>] flush_smp_call_function_queue+0xb4/0x154 1833.212926: <2> [<ffffffc00010efcc>] generic_smp_call_function_single_interrupt+0xc/0x18 1833.212932: <2> [<ffffffc000091050>] handle_IPI+0x120/0x338 1833.212937: <2> [<ffffffc000081580>] gic_handle_irq+0xb8/0xdc Here is the callstack which leads to this WARN. netdev_run_todo on_each_cpu //This disables irq with local_irq_save(flags) flush_backlog kfree_skb .. destroy_conntrack //This disables irq's again through local_bh_disable I noticed that this was introduced by commit ca7433df3a ("netfilter: conntrack: seperate expect locking from nf_conntrack_lock "). Since interrupts are already disabled when flush_backlog is called, is it expected to disable bottom halves in destroy_conntrack? -- Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html