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Date: Sat, 18 May 2024 07:18:36 -0700
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Subject: [syzbot] [input?] possible deadlock in evdev_cleanup (2)
From: syzbot <syzbot+77a2ec57108df22d5c63@syzkaller.appspotmail.com>
To: dmitry.torokhov@gmail.com, linux-input@vger.kernel.org, 
	linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
Content-Type: text/plain; charset="UTF-8"

Hello,

syzbot found the following issue on:

HEAD commit:    fda5695d692c Merge branch 'for-next/core' into for-kernelci
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=14de17c0980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=95dc1de8407c7270
dashboard link: https://syzkaller.appspot.com/bug?extid=77a2ec57108df22d5c63
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10298620980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=134d3182980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/07f3214ff0d9/disk-fda5695d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/70e2e2c864e8/vmlinux-fda5695d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b259942a16dc/Image-fda5695d.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+77a2ec57108df22d5c63@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.9.0-rc7-syzkaller-gfda5695d692c #0 Not tainted
------------------------------------------------------
syz-executor144/6248 is trying to acquire lock:
ffff0000d6b65110 (&evdev->mutex){+.+.}-{3:3}, at: evdev_mark_dead drivers/input/evdev.c:1314 [inline]
ffff0000d6b65110 (&evdev->mutex){+.+.}-{3:3}, at: evdev_cleanup+0x38/0x16c drivers/input/evdev.c:1323

but task is already holding lock:
ffff800090ffb888 (input_mutex){+.+.}-{3:3}, at: __input_unregister_device+0x2a4/0x5c0 drivers/input/input.c:2219

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (input_mutex){+.+.}-{3:3}:
       __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608
       __mutex_lock kernel/locking/mutex.c:752 [inline]
       mutex_lock_interruptible_nested+0x2c/0x38 kernel/locking/mutex.c:826
       input_register_device+0x8dc/0xde8 drivers/input/input.c:2389
       uinput_create_device+0x360/0x528 drivers/input/misc/uinput.c:365
       uinput_ioctl_handler+0x8b0/0x16c0 drivers/input/misc/uinput.c:904
       uinput_ioctl+0x38/0x4c drivers/input/misc/uinput.c:1075
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:904 [inline]
       __se_sys_ioctl fs/ioctl.c:890 [inline]
       __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:890
       __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152
       el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
       el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
       el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598

-> #2 (&newdev->mutex){+.+.}-{3:3}:
       __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608
       __mutex_lock kernel/locking/mutex.c:752 [inline]
       mutex_lock_interruptible_nested+0x2c/0x38 kernel/locking/mutex.c:826
       uinput_request_send drivers/input/misc/uinput.c:151 [inline]
       uinput_request_submit+0x188/0x654 drivers/input/misc/uinput.c:182
       uinput_dev_upload_effect+0x170/0x218 drivers/input/misc/uinput.c:257
       input_ff_upload+0x49c/0x834 drivers/input/ff-core.c:150
       evdev_do_ioctl drivers/input/evdev.c:1183 [inline]
       evdev_ioctl_handler+0x1fd0/0x2d58 drivers/input/evdev.c:1272
       evdev_ioctl+0x38/0x4c drivers/input/evdev.c:1281
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:904 [inline]
       __se_sys_ioctl fs/ioctl.c:890 [inline]
       __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:890
       __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152
       el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
       el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
       el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598

-> #1 (&ff->mutex){+.+.}-{3:3}:
       __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608
       __mutex_lock kernel/locking/mutex.c:752 [inline]
       mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804
       input_ff_upload+0x31c/0x834 drivers/input/ff-core.c:120
       evdev_do_ioctl drivers/input/evdev.c:1183 [inline]
       evdev_ioctl_handler+0x1fd0/0x2d58 drivers/input/evdev.c:1272
       evdev_ioctl+0x38/0x4c drivers/input/evdev.c:1281
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:904 [inline]
       __se_sys_ioctl fs/ioctl.c:890 [inline]
       __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:890
       __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152
       el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
       el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
       el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598

-> #0 (&evdev->mutex){+.+.}-{3:3}:
       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+0x3384/0x763c kernel/locking/lockdep.c:5137
       lock_acquire+0x248/0x73c kernel/locking/lockdep.c:5754
       __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608
       __mutex_lock kernel/locking/mutex.c:752 [inline]
       mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804
       evdev_mark_dead drivers/input/evdev.c:1314 [inline]
       evdev_cleanup+0x38/0x16c drivers/input/evdev.c:1323
       evdev_disconnect+0x58/0xc0 drivers/input/evdev.c:1407
       __input_unregister_device+0x31c/0x5c0 drivers/input/input.c:2222
       input_unregister_device+0xb0/0xfc drivers/input/input.c:2440
       uinput_destroy_device+0x5a4/0x79c drivers/input/misc/uinput.c:299
       uinput_release+0x44/0x60 drivers/input/misc/uinput.c:744
       __fput+0x30c/0x738 fs/file_table.c:422
       ____fput+0x20/0x30 fs/file_table.c:450
       task_work_run+0x230/0x2e0 kernel/task_work.c:180
       exit_task_work include/linux/task_work.h:38 [inline]
       do_exit+0x4e4/0x1ac8 kernel/exit.c:878
       do_group_exit+0x194/0x22c kernel/exit.c:1027
       __do_sys_exit_group kernel/exit.c:1038 [inline]
       __se_sys_exit_group kernel/exit.c:1036 [inline]
       pid_child_should_wake+0x0/0x1dc kernel/exit.c:1036
       __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152
       el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
       el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
       el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598

other info that might help us debug this:

Chain exists of:
  &evdev->mutex --> &newdev->mutex --> input_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(input_mutex);
                               lock(&newdev->mutex);
                               lock(input_mutex);
  lock(&evdev->mutex);

 *** DEADLOCK ***

1 lock held by syz-executor144/6248:
 #0: ffff800090ffb888 (input_mutex){+.+.}-{3:3}, at: __input_unregister_device+0x2a4/0x5c0 drivers/input/input.c:2219

stack backtrace:
CPU: 0 PID: 6248 Comm: syz-executor144 Not tainted 6.9.0-rc7-syzkaller-gfda5695d692c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call trace:
 dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:317
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:324
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:114
 dump_stack+0x1c/0x28 lib/dump_stack.c:123
 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2060
 check_noncircular+0x310/0x404 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+0x3384/0x763c kernel/locking/lockdep.c:5137
 lock_acquire+0x248/0x73c kernel/locking/lockdep.c:5754
 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608
 __mutex_lock kernel/locking/mutex.c:752 [inline]
 mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804
 evdev_mark_dead drivers/input/evdev.c:1314 [inline]
 evdev_cleanup+0x38/0x16c drivers/input/evdev.c:1323
 evdev_disconnect+0x58/0xc0 drivers/input/evdev.c:1407
 __input_unregister_device+0x31c/0x5c0 drivers/input/input.c:2222
 input_unregister_device+0xb0/0xfc drivers/input/input.c:2440
 uinput_destroy_device+0x5a4/0x79c drivers/input/misc/uinput.c:299
 uinput_release+0x44/0x60 drivers/input/misc/uinput.c:744
 __fput+0x30c/0x738 fs/file_table.c:422
 ____fput+0x20/0x30 fs/file_table.c:450
 task_work_run+0x230/0x2e0 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x4e4/0x1ac8 kernel/exit.c:878
 do_group_exit+0x194/0x22c kernel/exit.c:1027
 __do_sys_exit_group kernel/exit.c:1038 [inline]
 __se_sys_exit_group kernel/exit.c:1036 [inline]
 pid_child_should_wake+0x0/0x1dc kernel/exit.c:1036
 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598


---
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