INFO: task syz-executor.0:5441 blocked for more than 143 seconds. Not tainted 6.8.0-rc1-syzkaller-gecb1b8288dc7 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:28256 pid:5441 tgid:5441 ppid:5440 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0xf12/0x5c00 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0xe9/0x270 kernel/sched/core.c:6817 schedule_timeout+0x257/0x290 kernel/time/timer.c:2159 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x3e0/0x5f0 kernel/sched/completion.c:116 __do_sys_io_destroy fs/aio.c:1468 [inline] __se_sys_io_destroy fs/aio.c:1446 [inline] __x64_sys_io_destroy+0x183/0x1d0 fs/aio.c:1446 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x456e69 RSP: 002b:00007fbe2afff0d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000cf RAX: ffffffffffffffda RBX: 000000000055bf80 RCX: 0000000000456e69 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fbe2b805000 RBP: 00000000004b0ca0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004b0297 R13: 000000000000000b R14: 000000000055bf80 R15: 00007fffe16d1808 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d1acba0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8d1acba0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8d1acba0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614 2 locks held by getty/4821: #0: ffff8880293750a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc6/0x1490 drivers/tty/n_tty.c:2201 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc1-syzkaller-gecb1b8288dc7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x277/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x299/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf87/0x1210 kernel/hung_task.c:379 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4494 Comm: syslogd Not tainted 6.8.0-rc1-syzkaller-gecb1b8288dc7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 RIP: 0010:check_kcov_mode kernel/kcov.c:175 [inline] RIP: 0010:write_comp_data+0x2f/0x80 kernel/kcov.c:236 Code: f8 49 89 f1 65 48 8b 14 25 80 c2 03 00 65 8b 05 7f a4 7b 7e a9 00 01 ff 00 74 0f f6 c4 01 74 59 8b 82 fc 15 00 00 85 c0 74 4f <8b> 82 d8 15 00 00 83 f8 03 75 44 48 8b 82 e0 15 00 00 8b 92 dc 15 RSP: 0018:ffffc9000312f490 EFLAGS: 00000246 RAX: 0000000080000001 RBX: 0000000000000003 RCX: ffffffff813a4c8d RDX: ffff888045ed5940 RSI: 0000000000000004 RDI: 0000000000000001 RBP: ffffffff8ac9ccc0 R08: 0000000000000001 R09: 0000000000000004 R10: 0000000000000002 R11: 0000000000000001 R12: 0000000000000002 R13: 0000000000000001 R14: 0000000000000003 R15: 0000000000000002 FS: 00007f3e341ef380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000002948938 CR3: 000000002c269000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __sanitizer_cov_trace_switch+0x54/0x90 kernel/kcov.c:341 unwind_next_frame+0x77d/0x2390 arch/x86/kernel/unwind_orc.c:581 arch_stack_walk+0xfa/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x96/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3f/0x60 mm/kasan/generic.c:640 poison_slab_object mm/kasan/common.c:241 [inline] __kasan_slab_free+0x121/0x1b0 mm/kasan/common.c:257 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2121 [inline] slab_free mm/slub.c:4299 [inline] kfree+0x124/0x360 mm/slub.c:4409 skb_kfree_head net/core/skbuff.c:986 [inline] skb_free_head+0x110/0x1b0 net/core/skbuff.c:998 skb_release_data+0x5ba/0x870 net/core/skbuff.c:1028 skb_release_all net/core/skbuff.c:1094 [inline] __kfree_skb net/core/skbuff.c:1108 [inline] consume_skb net/core/skbuff.c:1324 [inline] consume_skb+0xd2/0x170 net/core/skbuff.c:1318 __unix_dgram_recvmsg+0x814/0xee0 net/unix/af_unix.c:2468 unix_dgram_recvmsg+0xc3/0xf0 net/unix/af_unix.c:2485 sock_recvmsg_nosec net/socket.c:1046 [inline] sock_recvmsg+0xe2/0x170 net/socket.c:1068 sock_read_iter+0x2c3/0x3c0 net/socket.c:1138 call_read_iter include/linux/fs.h:2079 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x9f3/0xb70 fs/read_write.c:476 ksys_read+0x1f0/0x250 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f3e34343b6a Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007fffa1581328 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f3e34343b6a RDX: 00000000000000ff RSI: 000055c6c9ef3950 RDI: 0000000000000000 RBP: 000055c6c9ef3910 R08: 0000000000000001 R09: 0000000000000000 R10: 00007f3e344e23a3 R11: 0000000000000246 R12: 000055c6c9ef39ac R13: 000055c6c9ef3950 R14: 0000000000000000 R15: 00007f3e34520a80