Hello, syzbot found the following issue on: HEAD commit: ed30a4a51bb1 Linux 6.9-rc5 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=111df107180000 kernel config: https://syzkaller.appspot.com/x/.config?x=545d4b3e07d6ccbc dashboard link: https://syzkaller.appspot.com/bug?extid=87da1f0dd6b631f8bfb9 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/3d0f558a8144/disk-ed30a4a5.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/ca1e84aa7770/vmlinux-ed30a4a5.xz kernel image: https://storage.googleapis.com/syzbot-assets/9183b6bdee8e/bzImage-ed30a4a5.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+87da1f0dd6b631f8bfb9@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc5-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/26340 is trying to acquire lock: ffff888062bca570 (&tty->read_wait){....}-{2:2}, at: __wake_up_common_lock kernel/sched/wait.c:105 [inline] ffff888062bca570 (&tty->read_wait){....}-{2:2}, at: __wake_up+0x1c/0x60 kernel/sched/wait.c:127 but task is already holding lock: ffff88807e9eb4c0 (&tty->ctrl.lock){....}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] ffff88807e9eb4c0 (&tty->ctrl.lock){....}-{2:2}, at: pty_flush_buffer+0xaf/0x120 drivers/tty/pty.c:213 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&tty->ctrl.lock){....}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __proc_set_tty+0x2c/0x6b0 drivers/tty/tty_jobctrl.c:102 tty_open_proc_set_tty+0x1f6/0x250 drivers/tty/tty_jobctrl.c:154 tty_open+0xdb0/0x1020 drivers/tty/tty_io.c:2184 chrdev_open+0x26d/0x6f0 fs/char_dev.c:414 do_dentry_open+0x8da/0x18c0 fs/open.c:955 do_open fs/namei.c:3642 [inline] path_openat+0x1dfb/0x2990 fs/namei.c:3799 do_filp_open+0x1dc/0x430 fs/namei.c:3826 do_sys_openat2+0x17a/0x1e0 fs/open.c:1406 do_sys_open fs/open.c:1421 [inline] __do_sys_openat fs/open.c:1437 [inline] __se_sys_openat fs/open.c:1432 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1432 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (&sighand->siglock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __lock_task_sighand+0xc2/0x340 kernel/signal.c:1414 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x290/0x300 kernel/signal.c:1453 bpf_send_signal_common+0x2e8/0x3a0 kernel/trace/bpf_trace.c:881 ____bpf_send_signal_thread kernel/trace/bpf_trace.c:898 [inline] bpf_send_signal_thread+0x16/0x20 kernel/trace/bpf_trace.c:896 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:1997 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2236 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run4+0x176/0x460 kernel/trace/bpf_trace.c:2422 __bpf_trace_mmap_lock_acquire_returned+0x134/0x180 include/trace/events/mmap_lock.h:52 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline] __mmap_lock_do_trace_acquire_returned+0x456/0x790 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:166 [inline] get_mmap_lock_carefully mm/memory.c:5633 [inline] lock_mm_and_find_vma+0xeb/0x580 mm/memory.c:5693 do_user_addr_fault+0x29c/0x1080 arch/x86/mm/fault.c:1385 handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1563 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 rep_movs_alternative+0x4a/0x70 arch/x86/lib/copy_user_64.S:65 copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:131 [inline] copy_to_user_iter lib/iov_iter.c:25 [inline] iterate_ubuf include/linux/iov_iter.h:29 [inline] iterate_and_advance2 include/linux/iov_iter.h:245 [inline] iterate_and_advance include/linux/iov_iter.h:271 [inline] _copy_to_iter+0x37e/0x1110 lib/iov_iter.c:185 copy_page_to_iter lib/iov_iter.c:362 [inline] copy_page_to_iter+0xf1/0x180 lib/iov_iter.c:349 pipe_read+0x543/0x1400 fs/pipe.c:327 call_read_iter include/linux/fs.h:2104 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x9fd/0xb80 fs/read_write.c:476 ksys_read+0x1f8/0x260 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (lock#10){+.+.}-{2:2}: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_acquire_returned+0x97/0x790 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:166 [inline] stack_map_get_build_id_offset+0x5df/0x7d0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x6bf/0x700 kernel/bpf/stackmap.c:449 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1985 [inline] bpf_get_stack_raw_tp+0x124/0x160 kernel/trace/bpf_trace.c:1975 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:1997 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2236 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run3+0x167/0x440 kernel/trace/bpf_trace.c:2421 __bpf_trace_workqueue_queue_work+0x101/0x140 include/trace/events/workqueue.h:23 trace_workqueue_queue_work include/trace/events/workqueue.h:23 [inline] __queue_work+0x627/0x1020 kernel/workqueue.c:2382 queue_work_on+0xf4/0x120 kernel/workqueue.c:2435 queue_work include/linux/workqueue.h:605 [inline] loop_queue_work drivers/block/loop.c:882 [inline] loop_queue_rq+0x5e5/0x1210 drivers/block/loop.c:1874 __blk_mq_issue_directly+0xe0/0x270 block/blk-mq.c:2595 blk_mq_try_issue_directly+0x1c8/0x410 block/blk-mq.c:2654 blk_mq_submit_bio+0x18fd/0x20f0 block/blk-mq.c:3019 __submit_bio+0xfd/0x310 block/blk-core.c:621 __submit_bio_noacct_mq block/blk-core.c:700 [inline] submit_bio_noacct_nocheck+0x98a/0xd50 block/blk-core.c:729 submit_bio_noacct+0x746/0x1ba0 block/blk-core.c:839 submit_bh fs/buffer.c:2809 [inline] __bread_slow fs/buffer.c:1267 [inline] __bread_gfp+0x1ac/0x370 fs/buffer.c:1477 sb_bread_unmovable include/linux/buffer_head.h:327 [inline] ntfs_bread+0xd9/0x210 fs/ntfs3/fsntfs.c:1025 ntfs_read_run_nb+0x3a0/0x8f0 fs/ntfs3/fsntfs.c:1245 ntfs_read_bh+0x3c/0xb0 fs/ntfs3/fsntfs.c:1313 mi_read+0x1e7/0x660 fs/ntfs3/record.c:133 ntfs_read_mft fs/ntfs3/inode.c:70 [inline] ntfs_iget5+0x4c2/0x3860 fs/ntfs3/inode.c:532 ntfs_fill_super+0x22ae/0x4490 fs/ntfs3/super.c:1328 get_tree_bdev+0x36f/0x610 fs/super.c:1614 vfs_get_tree+0x8f/0x380 fs/super.c:1779 do_new_mount fs/namespace.c:3352 [inline] path_mount+0x14e6/0x1f20 fs/namespace.c:3679 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount fs/namespace.c:3875 [inline] __x64_sys_mount+0x297/0x320 fs/namespace.c:3875 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&pool->lock){-.-.}-{2:2}: __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 __queue_work+0x39e/0x1020 kernel/workqueue.c:2360 queue_work_on+0xf4/0x120 kernel/workqueue.c:2435 queue_work include/linux/workqueue.h:605 [inline] schedule_work include/linux/workqueue.h:666 [inline] p9_pollwake+0xc1/0x1d0 net/9p/trans_fd.c:538 __wake_up_common+0x131/0x1e0 kernel/sched/wait.c:89 __wake_up_common_lock kernel/sched/wait.c:106 [inline] __wake_up+0x31/0x60 kernel/sched/wait.c:127 tty_set_termios+0x6db/0x9b0 drivers/tty/tty_ioctl.c:352 set_termios+0x57e/0x7f0 drivers/tty/tty_ioctl.c:516 tty_mode_ioctl+0x9dc/0xd20 drivers/tty/tty_ioctl.c:826 n_tty_ioctl_helper+0x4b/0x2b0 drivers/tty/tty_ioctl.c:986 n_tty_ioctl+0x7f/0x370 drivers/tty/n_tty.c:2511 tty_ioctl+0x6fa/0x1590 drivers/tty/tty_io.c:2812 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:890 [inline] __x64_sys_ioctl+0x193/0x220 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&tty->read_wait){....}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __wake_up_common_lock kernel/sched/wait.c:105 [inline] __wake_up+0x1c/0x60 kernel/sched/wait.c:127 pty_flush_buffer+0xf0/0x120 drivers/tty/pty.c:215 tty_driver_flush_buffer+0x61/0x80 drivers/tty/tty_ioctl.c:85 tty_ldisc_hangup+0xde/0x6a0 drivers/tty/tty_ldisc.c:694 __tty_hangup.part.0+0x426/0x8c0 drivers/tty/tty_io.c:630 __tty_hangup drivers/tty/tty_io.c:697 [inline] tty_vhangup drivers/tty/tty_io.c:700 [inline] tty_vhangup drivers/tty/tty_io.c:697 [inline] tty_ioctl+0xf4e/0x1590 drivers/tty/tty_io.c:2743 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:890 [inline] __x64_sys_ioctl+0x193/0x220 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &tty->read_wait --> &sighand->siglock --> &tty->ctrl.lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&tty->ctrl.lock); lock(&sighand->siglock); lock(&tty->ctrl.lock); lock(&tty->read_wait); *** DEADLOCK *** 3 locks held by syz-executor.4/26340: #0: ffff88807e9eb1c0 (&tty->legacy_mutex/1){+.+.}-{3:3}, at: __tty_hangup.part.0+0xbe/0x8c0 drivers/tty/tty_io.c:590 #1: ffff88807e9eb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref drivers/tty/tty_ldisc.c:263 [inline] #1: ffff88807e9eb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_hangup+0x30/0x6a0 drivers/tty/tty_ldisc.c:690 #2: ffff88807e9eb4c0 (&tty->ctrl.lock){....}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] #2: ffff88807e9eb4c0 (&tty->ctrl.lock){....}-{2:2}, at: pty_flush_buffer+0xaf/0x120 drivers/tty/pty.c:213 stack backtrace: CPU: 0 PID: 26340 Comm: syz-executor.4 Not tainted 6.9.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __wake_up_common_lock kernel/sched/wait.c:105 [inline] __wake_up+0x1c/0x60 kernel/sched/wait.c:127 pty_flush_buffer+0xf0/0x120 drivers/tty/pty.c:215 tty_driver_flush_buffer+0x61/0x80 drivers/tty/tty_ioctl.c:85 tty_ldisc_hangup+0xde/0x6a0 drivers/tty/tty_ldisc.c:694 __tty_hangup.part.0+0x426/0x8c0 drivers/tty/tty_io.c:630 __tty_hangup drivers/tty/tty_io.c:697 [inline] tty_vhangup drivers/tty/tty_io.c:700 [inline] tty_vhangup drivers/tty/tty_io.c:697 [inline] tty_ioctl+0xf4e/0x1590 drivers/tty/tty_io.c:2743 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:890 [inline] __x64_sys_ioctl+0x193/0x220 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5d1667dea9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5d173780c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f5d167abf80 RCX: 00007f5d1667dea9 RDX: 0000000000000000 RSI: 0000000000005437 RDI: 0000000000000006 RBP: 00007f5d166ca4a4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f5d167abf80 R15: 00007ffe8e31ef58 </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
