INFO: task syz-executor.3:27091 blocked for more than 143 seconds. Not tainted 5.7.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D29616 27091 7137 0x00000004 Call Trace: context_switch kernel/sched/core.c:3430 [inline] __schedule+0x8f3/0x1f90 kernel/sched/core.c:4156 schedule+0xd0/0x2a0 kernel/sched/core.c:4231 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4290 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7b3/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] do_fb_ioctl+0x1b5/0x6e0 drivers/video/fbdev/core/fbmem.c:1168 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:771 __do_sys_ioctl fs/ioctl.c:780 [inline] __se_sys_ioctl fs/ioctl.c:778 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:778 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca69 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f6330aaac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e4b40 RCX: 000000000045ca69 RDX: 0000000000000000 RSI: 0000000040044620 RDI: 0000000000000006 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002f3 R14: 00000000004c5722 R15: 00007f6330aab6d4 Showing all locks held in the system: 1 lock held by khungtaskd/1144: #0: ffffffff899be040 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5779 4 locks held by kworker/0:6/2518: 1 lock held by in:imklog/6530: #0: ffff8880a3626af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 2 locks held by agetty/6751: #0: ffff88809f36d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000eb42e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x220/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.3/27081: 1 lock held by syz-executor.3/27091: #0: ffff888218d5d078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218d5d078 (&fb_info->lock){+.+.}-{3:3}, at: do_fb_ioctl+0x1b5/0x6e0 drivers/video/fbdev/core/fbmem.c:1168 1 lock held by syz-executor.3/27130: #0: ffff888218d5d078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218d5d078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1144 Comm: khungtaskd Not tainted 5.7.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 2518 Comm: kworker/0:6 Not tainted 5.7.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events nsim_dev_trap_report_work RIP: 0010:unwind_next_frame+0x193/0x1df0 arch/x86/kernel/unwind_orc.c:446 Code: 41 f6 85 88 00 00 00 03 0f 85 b7 03 00 00 4d 8d 6f 35 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 0f b6 04 02 4c 89 ea <83> e2 07 38 d0 7f 08 84 c0 0f 85 0a 0a 00 00 4c 89 e1 41 0f b6 47 RSP: 0018:ffffc9000807f680 EFLAGS: 00000a03 RAX: 0000000000000000 RBX: 1ffff9200100fed8 RCX: 1ffffffff18d3624 RDX: ffffc9000807f78d RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000010200 R11: 000000000007001e R12: ffffc9000807f7a0 R13: ffffc9000807f78d R14: ffffc9000807f7a8 R15: ffffc9000807f758 FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561744f4aa40 CR3: 00000000a7ab3000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc mm/kasan/common.c:494 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:467 kmem_cache_alloc_node_trace+0x161/0x790 mm/slab.c:3595 __do_kmalloc_node mm/slab.c:3615 [inline] __kmalloc_node_track_caller+0x38/0x60 mm/slab.c:3630 __kmalloc_reserve.isra.0+0x39/0xe0 net/core/skbuff.c:142 __alloc_skb+0xef/0x5a0 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1083 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:500 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:557 [inline] nsim_dev_trap_report_work+0x2bb/0xbc0 drivers/net/netdevsim/dev.c:598 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351