lockdep null-ptr-deref

Qian Cai
2020-09-29T14:33:23Z

I tried to add a few new Kconfig options like LEDS_TRIGGERS instantly trigger a
warning during the boot, and then there is null-ptr-deref in lockdep below. Any
idea?

[ 16.487309] WARNING: possible irq lock inversion dependency detected
[ 16.488313] 5.9.0-rc7-next-20200928+ #9 Not tainted
[ 16.488936] --------------------------------------------------------
[ 16.489767] swapper/6/0 just changed the state of lock:
[ 16.490449] ffff8889eea6f418 (&host->lock){-...}-{2:2}, at: ata_bmdma_interrupt+0x1e/0x530 [libata]
__ata_sff_interrupt at /home/linux-mm/linux-next/drivers/ata/libata-sff.c:1534
(inlined by) ata_bmdma_interrupt at /home/linux-mm/linux-next/drivers/ata/libata-sff.c:2832
[ 16.491639] but this lock took another, HARDIRQ-READ-unsafe lock in the past:
[ 16.492561] (&trig->leddev_list_lock){.+.?}-{2:2}
[ 16.492565]
[ 16.492565]
[ 16.492565] and interrupts could create inverse lock ordering between them.
[ 16.492565]
[ 16.494635]
[ 16.494635] other info that might help us debug this:
[ 16.495479] Possible interrupt unsafe locking scenario:
[ 16.495479]
[ 16.496360] CPU0 CPU1
[ 16.496941] ---- ----
[ 16.497542] lock(&trig->leddev_list_lock);
[ 16.498095] local_irq_disable();
[ 16.498864] lock(&host->lock);
[ 16.499611] lock(&trig->leddev_list_lock);
[ 16.500481] <Interrupt>
[ 16.500833] lock(&host->lock);
[ 16.501289]
[ 16.501289] *** DEADLOCK ***
[ 16.501289]
[ 16.502044] no locks held by swapper/6/0.
[ 16.502566]
[ 16.502566] the shortest dependencies between 2nd lock and 1st lock:
[ 16.503578] -> (&trig->leddev_list_lock){.+.?}-{2:2} {
[ 16.504259] HARDIRQ-ON-R at:
[ 16.504692] lock_acquire+0x17f/0x7e0
[ 16.505411] _raw_read_lock+0x38/0x70
[ 16.506120] led_trigger_event+0x2b/0xb0
led_trigger_event at drivers/leds/led-triggers.c:386
(inlined by) led_trigger_event at drivers/leds/led-triggers.c:377
[ 16.506868] kbd_propagate_led_state+0x5d/0x80
[ 16.507680] kbd_bh+0x14d/0x1d0
[ 16.508335] tasklet_action_common.isra.13+0x23a/0x2e0
[ 16.509235] __do_softirq+0x1ce/0x828
[ 16.509940] run_ksoftirqd+0x26/0x50
[ 16.510647] smpboot_thread_fn+0x30f/0x740
[ 16.511413] kthread+0x357/0x420
[ 16.512068] ret_from_fork+0x22/0x30
[ 16.512762] IN-SOFTIRQ-R at:
[ 16.513187] lock_acquire+0x17f/0x7e0
[ 16.513891] _raw_read_lock+0x38/0x70
[ 16.514602] led_trigger_event+0x2b/0xb0
[ 16.515356] kbd_propagate_led_state+0x5d/0x80
[ 16.516165] kbd_bh+0x14d/0x1d0
[ 16.516810] tasklet_action_common.isra.13+0x23a/0x2e0
[ 16.517701] __do_softirq+0x1ce/0x828
[ 16.518418] run_ksoftirqd+0x26/0x50
[ 16.519119] smpboot_thread_fn+0x30f/0x740
[ 16.519874] kthread+0x357/0x420
[ 16.520460] scsi 0:0:0:0: Direct-Access ATA QEMU HARDDISK 2.5+ PQ: 0 ANSI: 5
[ 16.520528] ret_from_fork+0x22/0x30
[ 16.520531] SOFTIRQ-ON-R at:
[ 16.522704] lock_acquire+0x17f/0x7e0
[ 16.523423] _raw_read_lock+0x5d/0x70
[ 16.524124] led_trigger_event+0x2b/0xb0
[ 16.524865] kbd_propagate_led_state+0x5d/0x80
[ 16.525671] kbd_start+0xd2/0xf0
[ 16.526332] input_register_handle+0x282/0x4f0
[ 16.527142] kbd_connect+0xc0/0x120
[ 16.527826] input_attach_handler+0x10a/0x170
[ 16.528758] input_register_device.cold.22+0xac/0x29d
[ 16.529651] atkbd_connect+0x58f/0x810
[ 16.530374] serio_connect_driver+0x4a/0x70
[ 16.531144] really_probe+0x222/0xb20
[ 16.531861] driver_probe_device+0x1f6/0x380
[ 16.532650] device_driver_attach+0xea/0x120
[ 16.533441] __driver_attach+0xf5/0x270
[ 16.534172] bus_for_each_dev+0x11c/0x1b0
[ 16.534924] serio_handle_event+0x1df/0x7f0
[ 16.535701] process_one_work+0x842/0x1410
[ 16.536470] worker_thread+0x87/0xb40
[ 16.537178] kthread+0x357/0x420
[ 16.537828] ret_from_fork+0x22/0x30
[ 16.538674] INITIAL USE at:
[ 16.539220] lock_acquire+0x17f/0x7e0
[ 16.540116] _raw_read_lock+0x38/0x70
[ 16.540999] led_trigger_event+0x2b/0xb0
[ 16.541923] kbd_propagate_led_state+0x5d/0x80
[ 16.542879] kbd_bh+0x14d/0x1d0
[ 16.543538] tasklet_action_common.isra.13+0x23a/0x2e0
[ 16.544427] __do_softirq+0x1ce/0x828
[ 16.545117] run_ksoftirqd+0x26/0x50
[ 16.545807] smpboot_thread_fn+0x30f/0x740
[ 16.546566] kthread+0x357/0x420
[ 16.547227] ret_from_fork+0x22/0x30
[ 16.547899] (null) at:
[ 16.548298] general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN PTI
[ 16.549666] KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
[ 16.550644] CPU: 6 PID: 0 Comm: swapper/6 Not tainted 5.9.0-rc7-next-20200928+ #9
[ 16.551615] Hardware name: Red Hat KVM, BIOS 1.14.0-1.module+el8.3.0+7638+07cf13d2 04/01/2014
[ 16.552722] RIP: 0010:print_shortest_lock_dependencies.cold.65+0x10b/0x2a4
print_shortest_lock_dependencies.cold.65+0x10b/0x2a4:
print_lock_trace at kernel/locking/lockdep.c:1751
(inlined by) print_lock_class_header at kernel/locking/lockdep.c:2240
(inlined by) print_shortest_lock_dependencies at kernel/locking/lockdep.c:2263
[ 16.553613] Code: 41 01 c6 4c 89 e8 48 c1 e8 03 45 01 fe 80 3c 18 00 74 08 4c 89 ef e8 db e2 ac fe 49 8b 45 00 48 8d 78 14 48 89 fa 48 c1 ea 03 <0f> b6 0c 1a 48 89 fa 83 e2 07 83 c2 03 38 ca 7c 08 84 c9 0f 82
[ 16.555983] RSP: 0018:ffff888a7eb09988 EFLAGS: 00010003
[ 16.556658] RAX: 0000000000000001 RBX: dffffc0000000000 RCX: 0000000000000027
[ 16.557571] RDX: 0000000000000002 RSI: 0000000000000004 RDI: 0000000000000015
[ 16.558499] RBP: ffffffffb3dd5888 R08: ffffed114fd640c2 R09: ffffed114fd640c2
[ 16.559420] R10: ffff888a7eb2060b R11: ffffed114fd640c1 R12: 0000000000000009
[ 16.560329] R13: ffffffffb3dd5928 R14: 000000000000000f R15: 0000000000000001
[ 16.561237] FS: 0000000000000000(0000) GS:ffff888a7eb00000(0000) knlGS:0000000000000000
[ 16.562264] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 16.562989] CR2: 00007fdc00f597a0 CR3: 000000091f02e006 CR4: 0000000000770ee0
[ 16.563909] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 16.564818] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 16.565728] PKRU: 55555554
[ 16.566080] Call Trace:
[ 16.566410] <IRQ>
[ 16.566679] print_irq_inversion_bug.cold.66+0x31b/0x36e
print_irq_inversion_bug at kernel/locking/lockdep.c:3771
(inlined by) print_irq_inversion_bug at kernel/locking/lockdep.c:3716
[ 16.567369] mark_lock.part.49+0x116a/0x1900
[ 16.567915] ? print_usage_bug+0x1f0/0x1f0
[ 16.568456] ? __lock_acquire+0xc66/0x3ac0
[ 16.568983] ? print_usage_bug+0x1f0/0x1f0
[ 16.569521] ? mark_lock.part.49+0x107/0x1900
[ 16.570085] __lock_acquire+0x14ec/0x3ac0
[ 16.570610] ? static_obj+0xb0/0xc0
[ 16.571064] ? lockdep_hardirqs_on_prepare+0x4d0/0x4d0
[ 16.571731] ? rcu_read_lock_sched_held+0xa1/0xd0
[ 16.572347] lock_acquire+0x17f/0x7e0
[ 16.572825] ? ata_bmdma_interrupt+0x1e/0x530 [libata]
[ 16.573494] ? rcu_read_unlock+0x40/0x40
[ 16.573994] ? __lock_acquire+0x1864/0x3ac0
[ 16.574543] _raw_spin_lock_irqsave+0x35/0x50
[ 16.575111] ? ata_bmdma_interrupt+0x1e/0x530 [libata]
[ 16.575779] ? ata_bmdma_port_intr+0x320/0x320 [libata]
[ 16.576460] ata_bmdma_interrupt+0x1e/0x530 [libata]
[ 16.577092] ? rcu_read_lock_bh_held+0xb0/0xb0
[ 16.577676] ? find_held_lock+0x33/0x1c0
[ 16.578205] ? ata_bmdma_port_intr+0x320/0x320 [libata]
[ 16.578875] __handle_irq_event_percpu+0xeb/0x5f0
[ 16.579491] handle_irq_event_percpu+0x73/0x140
[ 16.580072] ? __handle_irq_event_percpu+0x5f0/0x5f0
[ 16.580714] ? rwlock_bug.part.1+0x90/0x90
[ 16.581251] ? do_raw_spin_unlock+0x14b/0x230
[ 16.581805] handle_irq_event+0xa1/0x130
[ 16.582324] handle_edge_irq+0x1ee/0x770
[ 16.582841] asm_call_irq_on_stack+0x12/0x20
[ 16.583416] </IRQ>
[ 16.583699] common_interrupt+0xe2/0x180
[ 16.584225] asm_common_interrupt+0x1e/0x40
[ 16.584760] RIP: 0010:default_idle+0x18/0x20
[ 16.585323] Code: 5d e9 bc cd 35 ff cc cc cc cc cc cc cc cc cc cc cc cc 0f 1f 44 00 00 e8 96 07 6b fe e9 07 00 00 00 0f 00 2d 4a 98 5b 00 fb f4 <c3> 0f 1f 80 00 00 00 00 0f 1f 44 00 00 53 be 08 00 00 00 65 4b
[ 16.587687] RSP: 0018:ffff888107317df8 EFLAGS: 00000202
[ 16.588378] RAX: 0000000000008ca1 RBX: 0000000000000006 RCX: ffffffffb143f2e0
[ 16.589297] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffb1464e4a
[ 16.590207] RBP: 0000000000000006 R08: 0000000000000001 R09: 0000000000000001
[ 16.591109] R10: ffff888a7eb360eb R11: ffffed114fd66c1d R12: ffffffffb2d6fca0
[ 16.592012] R13: 0000000000000000 R14: 1ffff11020e62fc6 R15: 0000000000000000
[ 16.592931] ? rcu_eqs_enter.constprop.75+0xa0/0xc0
[ 16.593572] ? default_idle+0xa/0x20
[ 16.594034] ? default_idle+0xa/0x20
[ 16.594511] default_idle_call+0xa0/0x370
[ 16.595028] do_idle+0x3c1/0x570
[ 16.595462] ? arch_cpu_idle_exit+0x40/0x40
[ 16.595995] ? lockdep_hardirqs_on_prepare+0x32b/0x4d0
[ 16.596663] ? _raw_spin_unlock_irqrestore+0x39/0x40
[ 16.597306] cpu_startup_entry+0x19/0x20
[ 16.597817] start_secondary+0x250/0x2f0
[ 16.598342] ? set_cpu_sibling_map+0x2430/0x2430
[ 16.598935] ? start_cpu0+0xc/0xc
[ 16.599378] secondary_startup_64_no_verify+0xb8/0xbb
[ 16.600017] Modules linked in: crct10dif_pclmul crc32_pclmul crc32c_intel virtiofs ata_piix ghash_clmulni_intel fuse libata serio_raw e1000(+) sunrpc dm_mirror dm_region_hash dm_log dm_mod
[ 16.602209] ---[ end trace f713527030b9fc6e ]---
[ 16.602804] RIP: 0010:print_shortest_lock_dependencies.cold.65+0x10b/0x2a4
[ 16.603695] Code: 41 01 c6 4c 89 e8 48 c1 e8 03 45 01 fe 80 3c 18 00 74 08 4c 89 ef e8 db e2 ac fe 49 8b 45 00 48 8d 78 14 48 89 fa 48 c1 ea 03 <0f> b6 0c 1a 48 89 fa 83 e2 07 83 c2 03 38 ca 7c 08 84 c9 0f 82
[ 16.606060] RSP: 0018:ffff888a7eb09988 EFLAGS: 00010003
[ 16.606730] RAX: 0000000000000001 RBX: dffffc0000000000 RCX: 0000000000000027
[ 16.607640] RDX: 0000000000000002 RSI: 0000000000000004 RDI: 0000000000000015
[ 16.608568] RBP: ffffffffb3dd5888 R08: ffffed114fd640c2 R09: ffffed114fd640c2
[ 16.609495] R10: ffff888a7eb2060b R11: ffffed114fd640c1 R12: 0000000000000009
[ 16.610410] R13: ffffffffb3dd5928 R14: 000000000000000f R15: 0000000000000001
[ 16.611322] FS: 0000000000000000(0000) GS:ffff888a7eb00000(0000) knlGS:0000000000000000
[ 16.612351] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 16.613078] CR2: 00007fdc00f597a0 CR3: 000000091f02e006 CR4: 0000000000770ee0
[ 16.613980] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 16.614903] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 16.615824] PKRU: 55555554
[ 16.616177] Kernel panic - not syncing: Fatal exception in interrupt
[ 16.617445] Kernel Offset: 0x2e600000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[ 16.618792] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---