usb 3-1: USB disconnect, device number 40 ================================================================== BUG: KASAN: slab-use-after-free in hdm_disconnect+0x227/0x250 drivers/most/most_usb.c:1125 Read of size 8 at addr ffff888050e41898 by task kworker/1:1/43 CPU: 1 UID: 0 PID: 43 Comm: kworker/1:1 Not tainted 6.16.0-rc4-syzkaller-00013-g66701750d556 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xcd/0x680 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 hdm_disconnect+0x227/0x250 drivers/most/most_usb.c:1125 usb_unbind_interface+0x1da/0x9a0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:569 [inline] device_remove+0x122/0x170 drivers/base/dd.c:561 __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x44b/0x620 drivers/base/dd.c:1295 bus_remove_device+0x22f/0x420 drivers/base/bus.c:579 device_del+0x396/0x9f0 drivers/base/core.c:3881 usb_disable_device+0x355/0x7d0 drivers/usb/core/message.c:1418 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2316 hub_port_connect drivers/usb/core/hub.c:5375 [inline] hub_port_connect_change drivers/usb/core/hub.c:5675 [inline] port_event drivers/usb/core/hub.c:5835 [inline] hub_event+0x1c57/0x4fa0 drivers/usb/core/hub.c:5917 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 43: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] hdm_probe+0xb3/0x19a0 drivers/most/most_usb.c:959 usb_probe_interface+0x300/0x9c0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x241/0xa90 drivers/base/dd.c:657 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:957 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:462 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1029 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537 device_add+0x1148/0x1a70 drivers/base/core.c:3692 usb_set_configuration+0x1187/0x1e20 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:250 usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x241/0xa90 drivers/base/dd.c:657 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:957 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:462 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1029 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537 device_add+0x1148/0x1a70 drivers/base/core.c:3692 usb_new_device+0xd07/0x1a20 drivers/usb/core/hub.c:2663 hub_port_connect drivers/usb/core/hub.c:5535 [inline] hub_port_connect_change drivers/usb/core/hub.c:5675 [inline] port_event drivers/usb/core/hub.c:5835 [inline] hub_event+0x2eb7/0x4fa0 drivers/usb/core/hub.c:5917 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 43: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4842 device_release+0xa1/0x240 drivers/base/core.c:2568 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1e7/0x5a0 lib/kobject.c:737 put_device drivers/base/core.c:3800 [inline] device_unregister+0x2f/0xc0 drivers/base/core.c:3923 hdm_disconnect+0x10b/0x250 drivers/most/most_usb.c:1123 usb_unbind_interface+0x1da/0x9a0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:569 [inline] device_remove+0x122/0x170 drivers/base/dd.c:561 __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x44b/0x620 drivers/base/dd.c:1295 bus_remove_device+0x22f/0x420 drivers/base/bus.c:579 device_del+0x396/0x9f0 drivers/base/core.c:3881 usb_disable_device+0x355/0x7d0 drivers/usb/core/message.c:1418 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2316 hub_port_connect drivers/usb/core/hub.c:5375 [inline] hub_port_connect_change drivers/usb/core/hub.c:5675 [inline] port_event drivers/usb/core/hub.c:5835 [inline] hub_event+0x1c57/0x4fa0 drivers/usb/core/hub.c:5917 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff888050e40000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 6296 bytes inside of freed 8192-byte region [ffff888050e40000, ffff888050e42000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x50e40 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b842280 ffffea000093ba00 dead000000000002 raw: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842280 ffffea000093ba00 dead000000000002 head: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001439001 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 16240, tgid 16239 (syz.0.2541), ts 817923026848, free_ts 816650288684 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab mm/slub.c:2619 [inline] new_slab+0x23b/0x330 mm/slub.c:2673 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3949 __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4354 kmalloc_noprof include/linux/slab.h:905 [inline] audit_log_d_path+0xe7/0x200 kernel/audit.c:2149 audit_log_d_path_exe+0x46/0x70 kernel/audit.c:2219 audit_log_task+0x31d/0x3f0 kernel/auditsc.c:2957 audit_seccomp+0x79/0x290 kernel/auditsc.c:3004 seccomp_log kernel/seccomp.c:1033 [inline] __seccomp_filter+0x7b6/0xea0 kernel/seccomp.c:1328 __secure_computing+0x287/0x3b0 kernel/seccomp.c:1388 syscall_trace_enter+0x89/0x260 kernel/entry/common.c:52 syscall_enter_from_user_mode_work include/linux/entry-common.h:170 [inline] syscall_enter_from_user_mode include/linux/entry-common.h:200 [inline] do_syscall_64+0x347/0x4c0 arch/x86/entry/syscall_64.c:90 page last free pid 16211 tgid 16203 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4204 taskstats_tgid_alloc kernel/taskstats.c:576 [inline] taskstats_exit+0x654/0xbe0 kernel/taskstats.c:615 do_exit+0x5d9/0x2bd0 kernel/exit.c:940 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888050e41780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888050e41800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888050e41880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888050e41900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888050e41980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================