RBP: 00007fa6014b83d0 R08: 00007fa6013c3fa7 R09: 0000000000000038 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa6013c4210 R13: 0000000000000001 R14: 00746f687370616e R15: 616e732f7665642f (NULL device *): loading /lib/firmware/dvb-usb-dib0700-1.20.fw failed with error -12 (NULL device *): Direct firmware load for dvb-usb-dib0700-1.20.fw failed with error -12 (NULL device *): Falling back to sysfs fallback for: dvb-usb-dib0700-1.20.fw ====================================================== WARNING: possible circular locking dependency detected 6.10.0-syzkaller-08280-g68b59730459e #0 Not tainted ------------------------------------------------------ syz-executor800/5113 is trying to acquire lock: ffffffff8e1df830 (umhelper_sem){++++}-{3:3}, at: usermodehelper_read_trylock+0x140/0x300 kernel/umh.c:215 but task is already holding lock: ffffffff8ec7df88 (dpm_list_mtx){+.+.}-{3:3}, at: device_pm_lock drivers/base/power/main.c:113 [inline] ffffffff8ec7df88 (dpm_list_mtx){+.+.}-{3:3}, at: dpm_for_each_dev+0x2b/0xc0 drivers/base/power/main.c:1961 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (dpm_list_mtx){+.+.}-{3:3}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5753 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 device_pm_add+0x78/0x320 drivers/base/power/main.c:137 device_add+0x5e8/0xbf0 drivers/base/core.c:3642 fw_load_sysfs_fallback drivers/base/firmware_loader/fallback.c:86 [inline] fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:162 [inline] firmware_fallback_sysfs+0x307/0x9e0 drivers/base/firmware_loader/fallback.c:238 _request_firmware+0xcf5/0x12b0 drivers/base/firmware_loader/main.c:914 request_firmware_work_func+0x12a/0x280 drivers/base/firmware_loader/main.c:1165 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (umhelper_sem){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5136 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5753 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526 usermodehelper_read_trylock+0x140/0x300 kernel/umh.c:215 fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:147 [inline] firmware_fallback_sysfs+0x184/0x9e0 drivers/base/firmware_loader/fallback.c:238 _request_firmware+0xcf5/0x12b0 drivers/base/firmware_loader/main.c:914 request_firmware drivers/base/firmware_loader/main.c:963 [inline] cache_firmware drivers/base/firmware_loader/main.c:1265 [inline] __async_dev_cache_fw_image+0xe7/0x320 drivers/base/firmware_loader/main.c:1379 async_schedule_node_domain+0xdc/0x110 kernel/async.c:221 async_schedule_domain include/linux/async.h:72 [inline] dev_cache_fw_image+0x36d/0x3e0 drivers/base/firmware_loader/main.c:1435 dpm_for_each_dev+0x58/0xc0 drivers/base/power/main.c:1963 device_cache_fw_images drivers/base/firmware_loader/main.c:1485 [inline] fw_pm_notify+0x24a/0x2f0 drivers/base/firmware_loader/main.c:1536 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93 notifier_call_chain_robust kernel/notifier.c:128 [inline] blocking_notifier_call_chain_robust+0xe8/0x1e0 kernel/notifier.c:353 pm_notifier_call_chain_robust+0x2c/0x60 kernel/power/main.c:102 snapshot_open+0x1a1/0x280 kernel/power/user.c:77 misc_open+0x313/0x390 drivers/char/misc.c:165 chrdev_open+0x5b0/0x630 fs/char_dev.c:414 do_dentry_open+0x970/0x1440 fs/open.c:959 vfs_open+0x3e/0x330 fs/open.c:1089 do_open fs/namei.c:3727 [inline] path_openat+0x2b3e/0x3470 fs/namei.c:3886 do_filp_open+0x235/0x490 fs/namei.c:3913 do_sys_openat2+0x13e/0x1d0 fs/open.c:1416 do_sys_open fs/open.c:1431 [inline] __do_sys_openat fs/open.c:1447 [inline] __se_sys_openat fs/open.c:1442 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1442 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(dpm_list_mtx); lock(umhelper_sem); lock(dpm_list_mtx); rlock(umhelper_sem); *** DEADLOCK *** 5 locks held by syz-executor800/5113: #0: ffffffff8eb397e8 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x5c/0x390 drivers/char/misc.c:129 #1: ffffffff8e1e9468 (system_transition_mutex){+.+.}-{3:3}, at: lock_system_sleep+0x60/0xa0 kernel/power/main.c:56 #2: ffffffff8e209910 ((pm_chain_head).rwsem){++++}-{3:3}, at: blocking_notifier_call_chain_robust+0xac/0x1e0 kernel/notifier.c:352 #3: ffffffff8ec82ee8 (fw_lock){+.+.}-{3:3}, at: device_cache_fw_images drivers/base/firmware_loader/main.c:1483 [inline] #3: ffffffff8ec82ee8 (fw_lock){+.+.}-{3:3}, at: fw_pm_notify+0x232/0x2f0 drivers/base/firmware_loader/main.c:1536 #4: ffffffff8ec7df88 (dpm_list_mtx){+.+.}-{3:3}, at: device_pm_lock drivers/base/power/main.c:113 [inline] #4: ffffffff8ec7df88 (dpm_list_mtx){+.+.}-{3:3}, at: dpm_for_each_dev+0x2b/0xc0 drivers/base/power/main.c:1961 stack backtrace: CPU: 0 PID: 5113 Comm: syz-executor800 Not tainted 6.10.0-syzkaller-08280-g68b59730459e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2186 check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5136 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5753 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526 usermodehelper_read_trylock+0x140/0x300 kernel/umh.c:215 fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:147 [inline] firmware_fallback_sysfs+0x184/0x9e0 drivers/base/firmware_loader/fallback.c:238 _request_firmware+0xcf5/0x12b0 drivers/base/firmware_loader/main.c:914 request_firmware drivers/base/firmware_loader/main.c:963 [inline] cache_firmware drivers/base/firmware_loader/main.c:1265 [inline] __async_dev_cache_fw_image+0xe7/0x320 drivers/base/firmware_loader/main.c:1379 async_schedule_node_domain+0xdc/0x110 kernel/async.c:221 async_schedule_domain include/linux/async.h:72 [inline] dev_cache_fw_image+0x36d/0x3e0 drivers/base/firmware_loader/main.c:1435 dpm_for_each_dev+0x58/0xc0 drivers/base/power/main.c:1963 device_cache_fw_images drivers/base/firmware_loader/main.c:1485 [inline] fw_pm_notify+0x24a/0x2f0 drivers/base/firmware_loader/main.c:1536 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93 notifier_call_chain_robust kernel/notifier.c:128 [inline] blocking_notifier_call_chain_robust+0xe8/0x1e0 kernel/notifier.c:353 pm_notifier_call_chain_robust+0x2c/0x60 kernel/power/main.c:102 snapshot_open+0x1a1/0x280 kernel/power/user.c:77 misc_open+0x313/0x390 drivers/char/misc.c:165 chrdev_open+0x5b0/0x630 fs/char_dev.c:414 do_dentry_open+0x970/0x1440 fs/open.c:959 vfs_open+0x3e/0x330 fs/open.c:1089 do_open fs/namei.c:3727 [inline] path_openat+0x2b3e/0x3470 fs/namei.c:3886 do_filp_open+0x235/0x490 fs/namei.c:3913 do_sys_openat2+0x13e/0x1d0 fs/open.c:1416 do_sys_open fs/open.c:1431 [inline] __do_sys_openat fs/open.c:1447 [inline] __se_sys_openat fs/open.c:1442 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1442 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa6014370c9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 1d 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:00007fa6013c4208 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fa6014b83d8 RCX: 00007fa6014370c9 RDX: 0000000000000000 RSI: 0000000020000080 RDI: ffffffffffffff9c RBP: 00007fa6014b83d0 R08: 00007fa6013c3fa7 R09: 0000000000000038 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa6013c4210 R13: 0000000000000001 R14: 00746f687370616e R15: 616e732f7665642f