usb 2-1: USB disconnect, device number 30 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 4354 at lib/refcount.c:28 refcount_warn_saturate+0x13c/0x174 lib/refcount.c:28 refcount_t: underflow; use-after-free. Modules linked in: Kernel panic - not syncing: kernel: panic_on_warn set ... CPU: 0 UID: 0 PID: 4354 Comm: kworker/0:54 Not tainted 6.16.0-rc1-syzkaller #0 PREEMPT Hardware name: ARM-Versatile Express Workqueue: usb_hub_wq hub_event Call trace: [<80201a00>] (dump_backtrace) from [<80201afc>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257) r7:00000000 r6:8282083c r5:00000000 r4:82259bd0 [<80201ae4>] (show_stack) from [<8021fd94>] (__dump_stack lib/dump_stack.c:94 [inline]) [<80201ae4>] (show_stack) from [<8021fd94>] (dump_stack_lvl+0x54/0x7c lib/dump_stack.c:120) [<8021fd40>] (dump_stack_lvl) from [<8021fdd4>] (dump_stack+0x18/0x1c lib/dump_stack.c:129) r5:00000000 r4:82a6dd18 [<8021fdbc>] (dump_stack) from [<80202614>] (panic+0x120/0x374 kernel/panic.c:382) [<802024f4>] (panic) from [<802585b8>] (check_panic_on_warn kernel/panic.c:273 [inline]) [<802024f4>] (panic) from [<802585b8>] (get_taint+0x0/0x1c kernel/panic.c:268) r3:8280c684 r2:00000001 r1:822406fc r0:822480ac r7:808c00f4 [<80258544>] (check_panic_on_warn) from [<8025871c>] (__warn+0x80/0x188 kernel/panic.c:777) [<8025869c>] (__warn) from [<80258a0c>] (warn_slowpath_fmt+0x1e8/0x1f4 kernel/panic.c:812) r8:00000009 r7:822b1be4 r6:dfaa1bfc r5:85882400 r4:00000000 [<80258828>] (warn_slowpath_fmt) from [<808c00f4>] (refcount_warn_saturate+0x13c/0x174 lib/refcount.c:28) r10:00000001 r9:829ca3e8 r8:858c4088 r7:858c7874 r6:84aa87b4 r5:858c7800 r4:83d21c00 [<808bffb8>] (refcount_warn_saturate) from [<819fce88>] (__refcount_sub_and_test include/linux/refcount.h:400 [inline]) [<808bffb8>] (refcount_warn_saturate) from [<819fce88>] (__refcount_dec_and_test include/linux/refcount.h:432 [inline]) [<808bffb8>] (refcount_warn_saturate) from [<819fce88>] (refcount_dec_and_test include/linux/refcount.h:450 [inline]) [<808bffb8>] (refcount_warn_saturate) from [<819fce88>] (kref_put include/linux/kref.h:64 [inline]) [<808bffb8>] (refcount_warn_saturate) from [<819fce88>] (kobject_put+0x158/0x1f4 lib/kobject.c:737) [<819fcd30>] (kobject_put) from [<80b307e8>] (put_device+0x18/0x1c drivers/base/core.c:3800) r7:858c7874 r6:84aa87b4 r5:858c7800 r4:84aa8000 [<80b307d0>] (put_device) from [<81418e74>] (hdm_disconnect+0x90/0x9c drivers/most/most_usb.c:1129) [<81418de4>] (hdm_disconnect) from [<80e8cd04>] (usb_unbind_interface+0x84/0x2b4 drivers/usb/core/driver.c:458) r7:858c7874 r6:858c7830 r5:00000000 r4:858c4000 [<80e8cc80>] (usb_unbind_interface) from [<80b38870>] (device_remove drivers/base/dd.c:569 [inline]) [<80e8cc80>] (usb_unbind_interface) from [<80b38870>] (device_remove+0x64/0x6c drivers/base/dd.c:561) r10:00000001 r9:858c4088 r8:00000044 r7:858c7874 r6:829ca3e8 r5:00000000 r4:858c7830 [<80b3880c>] (device_remove) from [<80b39d60>] (__device_release_driver drivers/base/dd.c:1272 [inline]) [<80b3880c>] (device_remove) from [<80b39d60>] (device_release_driver_internal+0x18c/0x200 drivers/base/dd.c:1295) r5:00000000 r4:858c7830 [<80b39bd4>] (device_release_driver_internal) from [<80b39dec>] (device_release_driver+0x18/0x1c drivers/base/dd.c:1318) r9:858c4088 r8:8335cc40 r7:8335cc38 r6:8335cc0c r5:858c7830 r4:8335cc30 [<80b39dd4>] (device_release_driver) from [<80b37ec4>] (bus_remove_device+0xcc/0x120 drivers/base/bus.c:579) [<80b37df8>] (bus_remove_device) from [<80b32220>] (device_del+0x148/0x38c drivers/base/core.c:3881) r9:858c4088 r8:85882400 r7:04208060 r6:00000000 r5:858c7830 r4:858c7874 [<80b320d8>] (device_del) from [<80e8a754>] (usb_disable_device+0xd4/0x1e8 drivers/usb/core/message.c:1418) r10:00000001 r9:00000000 r8:00000000 r7:858c7800 r6:858c4000 r5:84899748 r4:60000013 [<80e8a680>] (usb_disable_device) from [<80e7f4d0>] (usb_disconnect+0xec/0x29c drivers/usb/core/hub.c:2316) r9:83d21600 r8:858c40cc r7:84282000 r6:858c4088 r5:858c4000 r4:60000013 [<80e7f3e4>] (usb_disconnect) from [<80e82190>] (hub_port_connect drivers/usb/core/hub.c:5375 [inline]) [<80e7f3e4>] (usb_disconnect) from [<80e82190>] (hub_port_connect_change drivers/usb/core/hub.c:5675 [inline]) [<80e7f3e4>] (usb_disconnect) from [<80e82190>] (port_event drivers/usb/core/hub.c:5835 [inline]) [<80e7f3e4>] (usb_disconnect) from [<80e82190>] (hub_event+0xe78/0x194c drivers/usb/core/hub.c:5917) r10:00000001 r9:00000100 r8:83d03300 r7:858c4000 r6:84281800 r5:84282210 r4:00000001 [<80e81318>] (hub_event) from [<8027e2e8>] (process_one_work+0x1b4/0x4f4 kernel/workqueue.c:3238) r10:8335ce70 r9:8326f405 r8:85882400 r7:dddced40 r6:8326f400 r5:83d03300 r4:85a6a100 [<8027e134>] (process_one_work) from [<8027ef30>] (process_scheduled_works kernel/workqueue.c:3321 [inline]) [<8027e134>] (process_one_work) from [<8027ef30>] (worker_thread+0x1fc/0x3d8 kernel/workqueue.c:3402) r10:61c88647 r9:85882400 r8:85a6a12c r7:82804d40 r6:dddced40 r5:dddced60 r4:85a6a100 [<8027ed34>] (worker_thread) from [<80285f5c>] (kthread+0x12c/0x280 kernel/kthread.c:464) r10:00000000 r9:85a6a100 r8:8027ed34 r7:dfed1e60 r6:85a6a000 r5:85882400 r4:00000001 [<80285e30>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137) Exception stack(0xdfaa1fb0 to 0xdfaa1ff8) 1fa0: 00000000 00000000 00000000 00000000 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80285e30 r4:853ec900 Rebooting in 86400 seconds..