[ 95.849450][ T27] audit: type=1800 audit(1581868862.376:26): pid=9584 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 96.822895][ T27] kauditd_printk_skb: 2 callbacks suppressed [ 96.822907][ T27] audit: type=1800 audit(1581868863.366:29): pid=9584 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 96.850123][ T27] audit: type=1800 audit(1581868863.376:30): pid=9584 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.191' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 107.052499][ T9739] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 118.242353][ T9900] [ 118.244955][ T9900] ====================================================== [ 118.252020][ T9900] WARNING: possible circular locking dependency detected [ 118.259023][ T9900] 5.6.0-rc1-syzkaller #0 Not tainted [ 118.264632][ T9900] ------------------------------------------------------ [ 118.271749][ T9900] syz-executor713/9900 is trying to acquire lock: [ 118.278151][ T9900] ffff888092f7ea60 (&htab->buckets[i].lock){....}, at: htab_lru_map_delete_node+0xce/0x2f0 [ 118.288134][ T9900] [ 118.288134][ T9900] but task is already holding lock: [ 118.295494][ T9900] ffff88809ffb5218 (&l->lock){....}, at: bpf_lru_pop_free+0x67f/0x1670 [ 118.303747][ T9900] [ 118.303747][ T9900] which lock already depends on the new lock. [ 118.303747][ T9900] [ 118.314242][ T9900] [ 118.314242][ T9900] the existing dependency chain (in reverse order) is: [ 118.323488][ T9900] [ 118.323488][ T9900] -> #2 (&l->lock){....}: [ 118.330030][ T9900] _raw_spin_lock+0x2f/0x40 [ 118.335071][ T9900] bpf_lru_pop_free+0x67f/0x1670 [ 118.340529][ T9900] prealloc_lru_pop+0x2c/0xa0 [ 118.345716][ T9900] __htab_lru_percpu_map_update_elem+0x67e/0xa90 [ 118.352617][ T9900] bpf_percpu_hash_update+0x16e/0x210 [ 118.358563][ T9900] bpf_map_update_value.isra.0+0x2d7/0x8e0 [ 118.365338][ T9900] generic_map_update_batch+0x41f/0x610 [ 118.371518][ T9900] bpf_map_do_batch+0x3f5/0x510 [ 118.376889][ T9900] __do_sys_bpf+0x9b7/0x41e0 [ 118.382096][ T9900] __x64_sys_bpf+0x73/0xb0 [ 118.387032][ T9900] do_syscall_64+0xfa/0x790 [ 118.392151][ T9900] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 118.398639][ T9900] [ 118.398639][ T9900] -> #1 (&loc_l->lock){....}: [ 118.405486][ T9900] _raw_spin_lock_irqsave+0x95/0xcd [ 118.411195][ T9900] bpf_lru_push_free+0x250/0x5b0 [ 118.416658][ T9900] __htab_map_lookup_and_delete_batch+0x8d4/0x1540 [ 118.423729][ T9900] htab_lru_map_lookup_and_delete_batch+0x34/0x40 [ 118.430654][ T9900] bpf_map_do_batch+0x3f5/0x510 [ 118.436115][ T9900] __do_sys_bpf+0x1f7d/0x41e0 [ 118.441675][ T9900] __x64_sys_bpf+0x73/0xb0 [ 118.446642][ T9900] do_syscall_64+0xfa/0x790 [ 118.451656][ T9900] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 118.458048][ T9900] [ 118.458048][ T9900] -> #0 (&htab->buckets[i].lock){....}: [ 118.465763][ T9900] __lock_acquire+0x2596/0x4a00 [ 118.471169][ T9900] lock_acquire+0x190/0x410 [ 118.476178][ T9900] _raw_spin_lock_irqsave+0x95/0xcd [ 118.482024][ T9900] htab_lru_map_delete_node+0xce/0x2f0 [ 118.488073][ T9900] __bpf_lru_list_shrink+0xf9/0x470 [ 118.493800][ T9900] bpf_lru_pop_free+0x87c/0x1670 [ 118.499939][ T9900] prealloc_lru_pop+0x2c/0xa0 [ 118.505662][ T9900] __htab_lru_percpu_map_update_elem+0x67e/0xa90 [ 118.512496][ T9900] bpf_percpu_hash_update+0x16e/0x210 [ 118.518482][ T9900] bpf_map_update_value.isra.0+0x2d7/0x8e0 [ 118.524802][ T9900] generic_map_update_batch+0x41f/0x610 [ 118.530866][ T9900] bpf_map_do_batch+0x3f5/0x510 [ 118.536437][ T9900] __do_sys_bpf+0x9b7/0x41e0 [ 118.541715][ T9900] __x64_sys_bpf+0x73/0xb0 [ 118.546647][ T9900] do_syscall_64+0xfa/0x790 [ 118.551690][ T9900] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 118.558197][ T9900] [ 118.558197][ T9900] other info that might help us debug this: [ 118.558197][ T9900] [ 118.568434][ T9900] Chain exists of: [ 118.568434][ T9900] &htab->buckets[i].lock --> &loc_l->lock --> &l->lock [ 118.568434][ T9900] [ 118.581401][ T9900] Possible unsafe locking scenario: [ 118.581401][ T9900] [ 118.588947][ T9900] CPU0 CPU1 [ 118.594300][ T9900] ---- ---- [ 118.599779][ T9900] lock(&l->lock); [ 118.603573][ T9900] lock(&loc_l->lock); [ 118.610225][ T9900] lock(&l->lock); [ 118.616675][ T9900] lock(&htab->buckets[i].lock); [ 118.621688][ T9900] [ 118.621688][ T9900] *** DEADLOCK *** [ 118.621688][ T9900] [ 118.629843][ T9900] 3 locks held by syz-executor713/9900: [ 118.635378][ T9900] #0: ffffffff89bac240 (rcu_read_lock){....}, at: bpf_percpu_hash_update+0x0/0x210 [ 118.644741][ T9900] #1: ffffe8ffffc46828 (&loc_l->lock){....}, at: bpf_lru_pop_free+0x32b/0x1670 [ 118.653940][ T9900] #2: ffff88809ffb5218 (&l->lock){....}, at: bpf_lru_pop_free+0x67f/0x1670 [ 118.664436][ T9900] [ 118.664436][ T9900] stack backtrace: [ 118.670336][ T9900] CPU: 0 PID: 9900 Comm: syz-executor713 Not tainted 5.6.0-rc1-syzkaller #0 [ 118.678987][ T9900] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 118.689039][ T9900] Call Trace: [ 118.692337][ T9900] dump_stack+0x197/0x210 [ 118.696668][ T9900] print_circular_bug.isra.0.cold+0x163/0x172 [ 118.702784][ T9900] check_noncircular+0x32e/0x3e0 [ 118.707720][ T9900] ? do_huge_pmd_anonymous_page+0x1454/0x1a50 [ 118.713884][ T9900] ? print_circular_bug.isra.0+0x230/0x230 [ 118.719914][ T9900] ? do_huge_pmd_anonymous_page+0x1454/0x1a50 [ 118.725985][ T9900] ? alloc_list_entry+0xc0/0xc0 [ 118.730838][ T9900] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 118.737083][ T9900] ? find_first_zero_bit+0x9a/0xc0 [ 118.742191][ T9900] __lock_acquire+0x2596/0x4a00 [ 118.747135][ T9900] ? do_raw_spin_unlock+0x181/0x270 [ 118.752342][ T9900] ? mark_held_locks+0xf0/0xf0 [ 118.757134][ T9900] ? __kasan_check_read+0x11/0x20 [ 118.762150][ T9900] ? __lock_acquire+0x16f2/0x4a00 [ 118.767177][ T9900] lock_acquire+0x190/0x410 [ 118.771666][ T9900] ? htab_lru_map_delete_node+0xce/0x2f0 [ 118.777299][ T9900] _raw_spin_lock_irqsave+0x95/0xcd [ 118.782667][ T9900] ? htab_lru_map_delete_node+0xce/0x2f0 [ 118.788342][ T9900] htab_lru_map_delete_node+0xce/0x2f0 [ 118.793814][ T9900] ? __kasan_check_write+0x14/0x20 [ 118.798980][ T9900] __bpf_lru_list_shrink+0xf9/0x470 [ 118.804176][ T9900] bpf_lru_pop_free+0x87c/0x1670 [ 118.809204][ T9900] prealloc_lru_pop+0x2c/0xa0 [ 118.814028][ T9900] __htab_lru_percpu_map_update_elem+0x67e/0xa90 [ 118.820365][ T9900] bpf_percpu_hash_update+0x16e/0x210 [ 118.825783][ T9900] bpf_map_update_value.isra.0+0x2d7/0x8e0 [ 118.831757][ T9900] generic_map_update_batch+0x41f/0x610 [ 118.837298][ T9900] ? generic_map_delete_batch+0x6a0/0x6a0 [ 118.843068][ T9900] ? __fget_light+0x1ad/0x270 [ 118.847744][ T9900] ? generic_map_delete_batch+0x6a0/0x6a0 [ 118.853556][ T9900] bpf_map_do_batch+0x3f5/0x510 [ 118.858425][ T9900] __do_sys_bpf+0x9b7/0x41e0 [ 118.863011][ T9900] ? find_held_lock+0x35/0x130 [ 118.867865][ T9900] ? bpf_prog_load+0x1820/0x1820 [ 118.872903][ T9900] ? lock_downgrade+0x920/0x920 [ 118.877743][ T9900] ? handle_mm_fault+0x292/0xa50 [ 118.883220][ T9900] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 118.888668][ T9900] ? do_syscall_64+0x26/0x790 [ 118.893332][ T9900] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 118.899398][ T9900] ? do_syscall_64+0x26/0x790 [ 118.904065][ T9900] __x64_sys_bpf+0x73/0xb0 [ 118.908482][ T9900] do_syscall_64+0xfa/0x790 [ 118.912973][ T9900] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 118.918948][ T9900] RIP: 0033:0x446b19 [ 118.922856][ T9900] Code: e8 bc b4 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 executing program [ 118.942444][ T9900] RSP: 002b:00007f5fab28adb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 [ 118.950847][ T9900] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 0000000000446b19 [ 118.959016][ T9900] RDX: 0000000000000038 RSI: 0000000020000040 RDI: 000000000000001a [ 118.966986][ T9900] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 118.974954][ T9900] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 118.983157][ T9900] R13: 00007fffd97b3baf R14: 00007f5fab28b9c0 R15: 0000000000000000 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program