INFO: task syz-executor.0:29105 blocked for more than 143 seconds. Not tainted 5.7.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27280 29105 7022 0x00004004 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4083 schedule+0x188/0x220 kernel/sched/core.c:4158 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4217 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x498/0x580 fs/char_dev.c:414 cd_forget+0x150/0x150 include/linux/spinlock.h:393 do_dentry_open+0x82e/0x10b0 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x2790/0x38b0 fs/namei.c:3346 trace_hardirqs_on_thunk+0x1a/0x1c arch/x86/entry/thunk_64.S:41 trace_hardirqs_on_thunk+0x1a/0x1c arch/x86/entry/thunk_64.S:41 do_filp_open+0x191/0x3a0 fs/namei.c:3373 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock+0x24/0x40 kernel/locking/spinlock.c:183 spin_unlock include/linux/spinlock.h:393 [inline] __alloc_fd+0x566/0x600 fs/file.c:534 do_sys_openat2+0x463/0x770 fs/open.c:1148 do_sys_open fs/open.c:1164 [inline] __do_sys_openat fs/open.c:1178 [inline] __se_sys_openat fs/open.c:1173 [inline] __x64_sys_openat+0x1c8/0x1f0 fs/open.c:1173 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Showing all locks held in the system: 1 lock held by khungtaskd/1141: #0: ffffffff892e85d0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 net/mptcp/pm_netlink.c:860 5 locks held by kworker/0:9/4080: 1 lock held by in:imklog/6681: #0: ffff88809e1a3af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x25d/0x2f0 fs/file.c:826 2 locks held by agetty/6722: #0: ffff8880a6b16098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:267 #1: ffffc900010c02e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x260/0x1bc0 drivers/tty/n_tty.c:2156 2 locks held by agetty/6724: #0: ffff8880a7845098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:267 #1: ffffc900010f02e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x260/0x1bc0 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.0/29046: 1 lock held by syz-executor.0/29105: #0: ffff888218839078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218839078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1141 Comm: khungtaskd Not tainted 5.7.0-rc6-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+0x1e9/0x30e lib/dump_stack.c:118 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101 arch_trigger_cpumask_backtrace+0x10/0x10 arch/x86/kernel/apic/hw_nmi.c:38 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xd2a/0xd40 kernel/hung_task.c:289 kthread+0x353/0x380 kernel/kthread.c:268 hungtask_pm_notify+0x50/0x50 kernel/hung_task.c:265 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247 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: 4080 Comm: kworker/0:9 Not tainted 5.7.0-rc6-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:memcpy_erms+0x8/0x10 arch/x86/lib/memcpy_64.S:57 Code: eb a8 eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 f3 a4 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe 7c 35 RSP: 0018:ffffc900020dfaa8 EFLAGS: 00000002 RAX: ffffc900020dfac0 RBX: ffffc900020dfac0 RCX: 0000000000000000 RDX: 0000000000000040 RSI: ffff8880a03abb40 RDI: ffffc900020dfb00 RBP: ffffc900020dfb40 R08: dffffc0000000000 R09: fffff5200041bf60 R10: fffff5200041bf60 R11: 0000000000000000 R12: ffff8880a03abb00 R13: dffffc0000000000 R14: ffffc900020dfb88 R15: 0000000000000014 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c000067c80 CR3: 00000000a029e000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: chacha_block_generic+0x50/0xbb0 lib/crypto/chacha.c:82 atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:694 [inline] queued_spin_lock include/asm-generic/qspinlock.h:78 [inline] do_raw_spin_lock+0xfe/0x800 kernel/locking/spinlock_debug.c:113 chacha20_block include/crypto/chacha.h:40 [inline] _extract_crng+0x2c0/0x370 drivers/char/random.c:1010 extract_crng drivers/char/random.c:1026 [inline] _get_random_bytes+0x163/0x1b0 drivers/char/random.c:1562 __alloc_skb+0x380/0x4f0 net/core/skbuff.c:242 skb_put+0x114/0x1e0 net/core/skbuff.c:1866 eth_random_addr include/linux/etherdevice.h:224 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:499 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:549 [inline] nsim_dev_trap_report_work+0x317/0xb40 drivers/net/netdevsim/dev.c:590 process_one_work+0x76e/0xfd0 kernel/workqueue.c:2268 worker_thread+0xa7f/0x1450 kernel/workqueue.c:2414 kthread+0x353/0x380 kernel/kthread.c:268 rcu_lock_release+0x20/0x20 include/linux/rcupdate.h:213 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351