On Tue, 2020-12-15 at 01:44 -0800, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 7f376f19 Merge tag 'mtd/fixes-for-5.10-rc8' of git://git.k.. > git tree: net > console output: https://syzkaller.appspot.com/x/log.txt?x=13842287500000 > kernel config: https://syzkaller.appspot.com/x/.config?x=3416bb960d5c705d > dashboard link: https://syzkaller.appspot.com/bug?extid=8971da381fb5a31f542d > compiler: gcc (GCC) 10.1.0-syz 20200507 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=128c5745500000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17a1f123500000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+8971da381fb5a31f5...@syzkaller.appspotmail.com > > general protection fault, probably for non-canonical address > 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN > KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] > CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.10.0-rc7-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0010:taprio_dequeue_soft+0x22e/0xa40 net/sched/sch_taprio.c:544 > Code: 24 18 e8 d5 3e 4c fa 48 8b 44 24 10 80 38 00 0f 85 4c 07 00 00 48 8b 93 > c0 02 00 00 49 63 c5 4c 8d 24 c2 4c 89 e0 48 c1 e8 03 <80> 3c 28 00 0f 85 3c > 07 00 00 4d 8b 24 24 4d 85 e4 0f 84 87 03 00 > RSP: 0018:ffffc90000d90e08 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: ffff8880282e3800 RCX: ffffffff8723c557 > RDX: 0000000000000000 RSI: ffffffff8723c59b RDI: 0000000000000005 > RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8ebaf667 > R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000401 R15: ffff88801917e000 > FS: 0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000020000600 CR3: 0000000013cdc000 CR4: 00000000001506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <IRQ> > dequeue_skb net/sched/sch_generic.c:263 [inline] > qdisc_restart net/sched/sch_generic.c:366 [inline] > __qdisc_run+0x1ae/0x15e0 net/sched/sch_generic.c:384 > qdisc_run include/net/pkt_sched.h:131 [inline] > qdisc_run include/net/pkt_sched.h:123 [inline] > net_tx_action+0x4b9/0xbf0 net/core/dev.c:4915 > __do_softirq+0x2a0/0x9f6 kernel/softirq.c:298 > asm_call_irq_on_stack+0xf/0x20 > </IRQ> > __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] > run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] > do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77 > invoke_softirq kernel/softirq.c:393 [inline] > __irq_exit_rcu kernel/softirq.c:423 [inline] > irq_exit_rcu+0x132/0x200 kernel/softirq.c:435 > sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1091 > asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631 > RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] > RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:79 [inline] > RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:169 [inline] > RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline] > RIP: 0010:acpi_idle_do_entry+0x1c9/0x250 drivers/acpi/processor_idle.c:517 > Code: 5d 07 88 f8 84 db 75 ac e8 44 0f 88 f8 e8 bf cd 8d f8 e9 0c 00 00 00 e8 > 35 0f 88 f8 0f 00 2d 9e 86 c0 00 e8 29 0f 88 f8 fb f4 <9c> 5b 81 e3 00 02 00 > 00 fa 31 ff 48 89 de e8 84 07 88 f8 48 85 db > RSP: 0018:ffffc90000d27d18 EFLAGS: 00000293 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff19d8e91 > RDX: ffff888010d98000 RSI: ffffffff88e7f547 RDI: 0000000000000000 > RBP: ffff888014e50064 R08: 0000000000000001 R09: 0000000000000001 > R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 > R13: ffff888014e50000 R14: ffff888014e50064 R15: ffff88801747a804 > acpi_idle_enter+0x361/0x500 drivers/acpi/processor_idle.c:648 > cpuidle_enter_state+0x1b1/0xc80 drivers/cpuidle/cpuidle.c:237 > cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:351 > call_cpuidle kernel/sched/idle.c:158 [inline] > cpuidle_idle_call kernel/sched/idle.c:239 [inline] > do_idle+0x3e1/0x590 kernel/sched/idle.c:299 > cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:395 > start_secondary+0x266/0x340 arch/x86/kernel/smpboot.c:266 > secondary_startup_64_no_verify+0xb0/0xbb > Modules linked in: > ---[ end trace 86b7dd17b9a0a261 ]--- > RIP: 0010:taprio_dequeue_soft+0x22e/0xa40 net/sched/sch_taprio.c:544 > Code: 24 18 e8 d5 3e 4c fa 48 8b 44 24 10 80 38 00 0f 85 4c 07 00 00 48 8b 93 > c0 02 00 00 49 63 c5 4c 8d 24 c2 4c 89 e0 48 c1 e8 03 <80> 3c 28 00 0f 85 3c > 07 00 00 4d 8b 24 24 4d 85 e4 0f 84 87 03 00 > RSP: 0018:ffffc90000d90e08 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: ffff8880282e3800 RCX: ffffffff8723c557 > RDX: 0000000000000000 RSI: ffffffff8723c59b RDI: 0000000000000005 > RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8ebaf667 > R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000401 R15: ffff88801917e000 > FS: 0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000020000600 CR3: 0000000013cdc000 CR4: 00000000001506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkal...@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this issue, for details see: > https://goo.gl/tpsmEJ#testing-patches >
I think we need to flush "child" qdiscs before freeing them in taprio_destroy(): I will try a small patch in the afternoon. thanks! -- davide
