====================================================== WARNING: possible circular locking dependency detected 5.10.161 #1 Not tainted ------------------------------------------------------ syz-executor.3/31138 is trying to acquire lock: ffff888048598958 (&sighand->siglock){-.-.}-{2:2}, at: __lock_task_sighand+0xd3/0x2f0 kernel/signal.c:1391 but task is already holding lock: ffff88800d067578 (&tty->read_wait){....}-{2:2}, at: __wake_up_common_lock+0xb4/0x140 kernel/sched/wait.c:122 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&tty->read_wait){....}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x60 kernel/locking/spinlock.c:159 __wake_up_common_lock+0xb4/0x140 kernel/sched/wait.c:122 pty_flush_buffer+0x124/0x160 drivers/tty/pty.c:225 tty_driver_flush_buffer+0x60/0x80 drivers/tty/tty_ioctl.c:95 tty_ldisc_hangup+0xdb/0x690 drivers/tty/tty_ldisc.c:726 __tty_hangup.part.0+0x510/0x9b0 drivers/tty/tty_io.c:624 __tty_hangup drivers/tty/tty_io.c:574 [inline] tty_vhangup drivers/tty/tty_io.c:697 [inline] tty_ioctl+0x1212/0x1840 drivers/tty/tty_io.c:2683 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xc6 -> #1 (&tty->ctrl_lock){....}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x60 kernel/locking/spinlock.c:159 __proc_set_tty+0x2c/0x620 drivers/tty/tty_jobctrl.c:98 proc_set_tty drivers/tty/tty_jobctrl.c:121 [inline] tiocsctty drivers/tty/tty_jobctrl.c:387 [inline] tty_jobctrl_ioctl+0x582/0xe20 drivers/tty/tty_jobctrl.c:564 tty_ioctl+0x1365/0x1840 drivers/tty/tty_io.c:2737 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xc6 -> #0 (&sighand->siglock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain kernel/locking/lockdep.c:3728 [inline] __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4954 lock_acquire kernel/locking/lockdep.c:5565 [inline] lock_acquire+0x197/0x490 kernel/locking/lockdep.c:5530 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x60 kernel/locking/spinlock.c:159 __lock_task_sighand+0xd3/0x2f0 kernel/signal.c:1391 lock_task_sighand include/linux/sched/signal.h:693 [inline] task_work_add+0x1df/0x2b0 kernel/task_work.c:58 io_req_task_work_add fs/io_uring.c:2070 [inline] __io_async_wake+0x40b/0x8d0 fs/io_uring.c:4950 __wake_up_common+0x14c/0x4c0 kernel/sched/wait.c:93 __wake_up_common_lock+0xd0/0x140 kernel/sched/wait.c:123 tty_ldisc_lock+0x40/0xb0 drivers/tty/tty_ldisc.c:335 tty_set_ldisc+0x92/0x680 drivers/tty/tty_ldisc.c:562 tiocsetd drivers/tty/tty_io.c:2420 [inline] tty_ioctl+0x6cc/0x1840 drivers/tty/tty_io.c:2679 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xc6 other info that might help us debug this: Chain exists of: &sighand->siglock --> &tty->ctrl_lock --> &tty->read_wait Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&tty->read_wait); lock(&tty->ctrl_lock); lock(&tty->read_wait); lock(&sighand->siglock); *** DEADLOCK *** 3 locks held by syz-executor.3/31138: #0: ffff88800d0671c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_lock+0xbd/0x120 drivers/tty/tty_mutex.c:19 #1: ffff88800d067578 (&tty->read_wait){....}-{2:2}, at: __wake_up_common_lock+0xb4/0x140 kernel/sched/wait.c:122 #2: ffffffff84ff82e0 (rcu_read_lock){....}-{1:2}, at: __lock_task_sighand+0x0/0x2f0 kernel/signal.c:1353 stack backtrace: CPU: 1 PID: 31138 Comm: syz-executor.3 Not tainted 5.10.161 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 check_noncircular+0x263/0x2e0 kernel/locking/lockdep.c:2123 check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain kernel/locking/lockdep.c:3728 [inline] __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4954 lock_acquire kernel/locking/lockdep.c:5565 [inline] lock_acquire+0x197/0x490 kernel/locking/lockdep.c:5530 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x60 kernel/locking/spinlock.c:159 __lock_task_sighand+0xd3/0x2f0 kernel/signal.c:1391 lock_task_sighand include/linux/sched/signal.h:693 [inline] task_work_add+0x1df/0x2b0 kernel/task_work.c:58 io_req_task_work_add fs/io_uring.c:2070 [inline] __io_async_wake+0x40b/0x8d0 fs/io_uring.c:4950 __wake_up_common+0x14c/0x4c0 kernel/sched/wait.c:93 __wake_up_common_lock+0xd0/0x140 kernel/sched/wait.c:123 tty_ldisc_lock+0x40/0xb0 drivers/tty/tty_ldisc.c:335 tty_set_ldisc+0x92/0x680 drivers/tty/tty_ldisc.c:562 tiocsetd drivers/tty/tty_io.c:2420 [inline] tty_ioctl+0x6cc/0x1840 drivers/tty/tty_io.c:2679 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xc6 RIP: 0033:0x7f27812d1b19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f277e847188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f27813e4f60 RCX: 00007f27812d1b19 RDX: 00000000200000c0 RSI: 0000000000005423 RDI: 0000000000000004 RBP: 00007f278132bf6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd6b13b51f R14: 00007f277e847300 R15: 0000000000022000 EXT4-fs (loop6): couldn't mount as ext2 due to feature incompatibilities EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue EXT4-fs (loop6): couldn't mount as ext2 due to feature incompatibilities print_req_error: 26 callbacks suppressed blk_update_request: I/O error, dev loop5, sector 2 op 0x0:(READ) flags 0x1000 phys_seg 1 prio class 0 EXT4-fs (loop5): unable to read superblock EXT4-fs (loop5): mounted filesystem without journal. Opts: (null) netlink: 4080 bytes leftover after parsing attributes in process `syz-executor.1'. EXT4-fs (loop6): couldn't mount as ext2 due to feature incompatibilities 9pnet: p9_fd_create_tcp (31137): problem connecting socket to 127.0.0.1 netlink: 4080 bytes leftover after parsing attributes in process `syz-executor.1'. EXT4-fs (loop6): couldn't mount as ext2 due to feature incompatibilities EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue EXT4-fs (loop5): mounted filesystem without journal. Opts: (null) EXT4-fs (loop5): mounted filesystem without journal. Opts: (null) netlink: 4080 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 4080 bytes leftover after parsing attributes in process `syz-executor.1'. blk_update_request: I/O error, dev loop5, sector 2 op 0x0:(READ) flags 0x1000 phys_seg 1 prio class 0 EXT4-fs (loop5): unable to read superblock 9pnet: p9_fd_create_tcp (31679): problem connecting socket to 127.0.0.1 serio: Serial port tty24 Option 'ŒÐþàB€Ž!ǯR ™–Â1u¡±Bî$×êè’YØ}Àb›Ž¿dpØ|chùºù~ú°þ„¤ù—ÂĨŽH&Û¾­-K ßÂøƒø1³‡Ú6³\' to dns_resolver key: bad/missing value TCP: request_sock_TCPv6: Possible SYN flooding on port 20000. Sending cookies. Check SNMP counters. serio: Serial port tty24 Option 'ŒÐþàB€Ž!ǯR ™–Â1u¡±Bî$×êè’YØ}Àb›Ž¿dpØ|chùºù~ú°þ„¤ù—ÂĨŽH&Û¾­-K ßÂøƒø1³‡Ú6³\' to dns_resolver key: bad/missing value serio: Serial port tty24 Option 'ŒÐþàB€Ž!ǯR ™–Â1u¡±Bî$×êè’YØ}Àb›Ž¿dpØ|chùºù~ú°þ„¤ù—ÂĨŽH&Û¾­-K ßÂøƒø1³‡Ú6³\' to dns_resolver key: bad/missing value serio: Serial port tty24 Option 'ŒÐþàB€Ž!ǯR ™–Â1u¡±Bî$×êè’YØ}Àb›Ž¿dpØ|chùºù~ú°þ„¤ù—ÂĨŽH&Û¾­-K ßÂøƒø1³‡Ú6³\' to dns_resolver key: bad/missing value ieee80211 phy49: Selected rate control algorithm 'minstrel_ht' ieee80211 phy50: Selected rate control algorithm 'minstrel_ht' ieee80211 phy51: Selected rate control algorithm 'minstrel_ht' ieee80211 phy52: Selected rate control algorithm 'minstrel_ht' EXT4-fs warning (device sda): verify_group_input:146: Cannot add at group 511 (only 16 groups) EXT4-fs warning (device sda): verify_group_input:146: Cannot add at group 511 (only 16 groups) audit: type=1400 audit(1672504504.177:87): avc: denied { checkpoint_restore } for pid=33005 comm="syz-executor.2" capability=40 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=capability2 permissive=1 EXT4-fs warning (device sda): verify_group_input:146: Cannot add at group 511 (only 16 groups) EXT4-fs warning (device sda): verify_group_input:146: Cannot add at group 511 (only 16 groups)