Warning: Permanently added '10.128.0.153' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 91.481107][ T9712] [ 91.483571][ T9712] ====================================================== [ 91.490687][ T9712] WARNING: possible circular locking dependency detected [ 91.497696][ T9712] 5.6.0-rc3-syzkaller #0 Not tainted [ 91.503104][ T9712] ------------------------------------------------------ [ 91.510107][ T9712] syz-executor517/9712 is trying to acquire lock: [ 91.516777][ T9712] ffff88809849f2a0 (&tty->termios_rwsem){++++}, at: n_tty_receive_buf_common+0x8a/0x2b70 [ 91.526577][ T9712] [ 91.526577][ T9712] but task is already holding lock: [ 91.533932][ T9712] ffffffff8a13cc40 (sel_lock){+.+.}, at: paste_selection+0x15a/0x4d0 [ 91.542000][ T9712] [ 91.542000][ T9712] which lock already depends on the new lock. [ 91.542000][ T9712] [ 91.552385][ T9712] [ 91.552385][ T9712] the existing dependency chain (in reverse order) is: [ 91.561995][ T9712] [ 91.561995][ T9712] -> #2 (sel_lock){+.+.}: [ 91.568495][ T9712] __mutex_lock+0x156/0x13c0 [ 91.573594][ T9712] mutex_lock_nested+0x16/0x20 [ 91.578870][ T9712] set_selection_kernel+0x39d/0x13d0 [ 91.584729][ T9712] set_selection_user+0x95/0xd9 [ 91.590083][ T9712] tioclinux+0x11c/0x480 [ 91.594838][ T9712] vt_ioctl+0x1a41/0x26c0 [ 91.599674][ T9712] tty_ioctl+0xa37/0x14f0 [ 91.604512][ T9712] ksys_ioctl+0x123/0x180 [ 91.609346][ T9712] __x64_sys_ioctl+0x73/0xb0 [ 91.614797][ T9712] do_syscall_64+0xfa/0x790 [ 91.619854][ T9712] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 91.626408][ T9712] [ 91.626408][ T9712] -> #1 (console_lock){+.+.}: [ 91.633258][ T9712] console_lock+0x47/0x80 [ 91.638099][ T9712] con_flush_chars+0x3d/0xa0 [ 91.643195][ T9712] n_tty_write+0xc85/0x1080 [ 91.648206][ T9712] tty_write+0x496/0x7f0 [ 91.653073][ T9712] __vfs_write+0x8a/0x110 [ 91.657908][ T9712] vfs_write+0x268/0x5d0 [ 91.662774][ T9712] ksys_write+0x14f/0x290 [ 91.667629][ T9712] __x64_sys_write+0x73/0xb0 [ 91.672904][ T9712] do_syscall_64+0xfa/0x790 [ 91.677917][ T9712] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 91.684429][ T9712] [ 91.684429][ T9712] -> #0 (&tty->termios_rwsem){++++}: [ 91.691929][ T9712] __lock_acquire+0x2596/0x4a00 [ 91.697283][ T9712] lock_acquire+0x190/0x410 [ 91.702290][ T9712] down_read+0x95/0x430 [ 91.706951][ T9712] n_tty_receive_buf_common+0x8a/0x2b70 [ 91.712998][ T9712] n_tty_receive_buf2+0x34/0x40 [ 91.718352][ T9712] tty_ldisc_receive_buf+0xad/0x1c0 [ 91.724071][ T9712] paste_selection+0x1ff/0x4d0 [ 91.729358][ T9712] tioclinux+0x133/0x480 [ 91.734350][ T9712] vt_ioctl+0x1a41/0x26c0 [ 91.739226][ T9712] tty_ioctl+0xa37/0x14f0 [ 91.744063][ T9712] ksys_ioctl+0x123/0x180 [ 91.748897][ T9712] __x64_sys_ioctl+0x73/0xb0 [ 91.754003][ T9712] do_syscall_64+0xfa/0x790 [ 91.759020][ T9712] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 91.765417][ T9712] [ 91.765417][ T9712] other info that might help us debug this: [ 91.765417][ T9712] [ 91.775641][ T9712] Chain exists of: [ 91.775641][ T9712] &tty->termios_rwsem --> console_lock --> sel_lock [ 91.775641][ T9712] [ 91.788125][ T9712] Possible unsafe locking scenario: [ 91.788125][ T9712] [ 91.795770][ T9712] CPU0 CPU1 [ 91.801127][ T9712] ---- ---- [ 91.806600][ T9712] lock(sel_lock); [ 91.810456][ T9712] lock(console_lock); [ 91.817234][ T9712] lock(sel_lock); [ 91.823705][ T9712] lock(&tty->termios_rwsem); [ 91.828557][ T9712] [ 91.828557][ T9712] *** DEADLOCK *** [ 91.828557][ T9712] [ 91.836946][ T9712] 3 locks held by syz-executor517/9712: [ 91.842473][ T9712] #0: ffff88809849f090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 91.851586][ T9712] #1: ffff8880aa5be0a8 (&buf->lock){+.+.}, at: tty_buffer_lock_exclusive+0x30/0x40 [ 91.860958][ T9712] #2: ffffffff8a13cc40 (sel_lock){+.+.}, at: paste_selection+0x15a/0x4d0 [ 91.869605][ T9712] [ 91.869605][ T9712] stack backtrace: [ 91.875627][ T9712] CPU: 0 PID: 9712 Comm: syz-executor517 Not tainted 5.6.0-rc3-syzkaller #0 [ 91.884482][ T9712] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 91.894683][ T9712] Call Trace: [ 91.898094][ T9712] dump_stack+0x197/0x210 [ 91.902415][ T9712] print_circular_bug.isra.0.cold+0x163/0x172 [ 91.908620][ T9712] check_noncircular+0x32e/0x3e0 [ 91.913556][ T9712] ? print_circular_bug.isra.0+0x230/0x230 [ 91.919414][ T9712] ? alloc_list_entry+0xc0/0xc0 [ 91.924275][ T9712] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 91.930507][ T9712] ? find_first_zero_bit+0x9a/0xc0 [ 91.935714][ T9712] __lock_acquire+0x2596/0x4a00 [ 91.940557][ T9712] ? save_trace+0x49/0x830 [ 91.944968][ T9712] ? mark_held_locks+0xf0/0xf0 [ 91.950008][ T9712] lock_acquire+0x190/0x410 [ 91.954508][ T9712] ? n_tty_receive_buf_common+0x8a/0x2b70 [ 91.960228][ T9712] down_read+0x95/0x430 [ 91.964384][ T9712] ? n_tty_receive_buf_common+0x8a/0x2b70 [ 91.970104][ T9712] ? down_read_killable+0x490/0x490 [ 91.975296][ T9712] n_tty_receive_buf_common+0x8a/0x2b70 [ 91.980957][ T9712] ? paste_selection+0x15a/0x4d0 [ 91.986007][ T9712] ? mark_lock+0xc2/0x1220 [ 91.990665][ T9712] ? mutex_trylock+0x2d0/0x2d0 [ 91.995494][ T9712] ? mark_held_locks+0xa4/0xf0 [ 92.000260][ T9712] ? lockdep_hardirqs_on+0x421/0x5e0 [ 92.005669][ T9712] n_tty_receive_buf2+0x34/0x40 [ 92.010576][ T9712] tty_ldisc_receive_buf+0xad/0x1c0 [ 92.015766][ T9712] ? n_tty_receive_buf_common+0x2b70/0x2b70 [ 92.021657][ T9712] paste_selection+0x1ff/0x4d0 [ 92.026414][ T9712] ? sel_pos+0x90/0x90 [ 92.030474][ T9712] ? lock_downgrade+0x920/0x920 [ 92.035313][ T9712] ? wake_up_q+0x140/0x140 [ 92.039716][ T9712] tioclinux+0x133/0x480 [ 92.043953][ T9712] vt_ioctl+0x1a41/0x26c0 [ 92.048273][ T9712] ? complete_change_console+0x3a0/0x3a0 [ 92.054016][ T9712] ? tomoyo_execute_permission+0x4a0/0x4a0 [ 92.060005][ T9712] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 92.065889][ T9712] ? tty_jobctrl_ioctl+0x50/0xd40 [ 92.070913][ T9712] ? complete_change_console+0x3a0/0x3a0 [ 92.076543][ T9712] tty_ioctl+0xa37/0x14f0 [ 92.080871][ T9712] ? tty_vhangup+0x30/0x30 [ 92.085287][ T9712] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 92.091637][ T9712] ? do_vfs_ioctl+0x568/0x13b0 [ 92.096389][ T9712] ? ioctl_file_clone+0x180/0x180 [ 92.101412][ T9712] ? file_open_root+0x430/0x430 [ 92.106394][ T9712] ? tomoyo_file_ioctl+0x23/0x30 [ 92.111324][ T9712] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 92.117561][ T9712] ? security_file_ioctl+0x8d/0xc0 [ 92.122667][ T9712] ? tty_vhangup+0x30/0x30 [ 92.127194][ T9712] ksys_ioctl+0x123/0x180 [ 92.131519][ T9712] __x64_sys_ioctl+0x73/0xb0 [ 92.136223][ T9712] do_syscall_64+0xfa/0x790 [ 92.140972][ T9712] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 92.146857][ T9712] RIP: 0033:0x440239 [ 92.150741][ T9712] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 5b 14 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 92.170467][ T9712] RSP: 002b:00007ffe25f55738 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 92.179009][ T9712] RAX: ffffffffffffffda RBX: 00000000