usb 7-1: USB disconnect, device number 5 ================================================================== BUG: KASAN: use-after-free in hdm_disconnect+0x109/0x1c0 drivers/most/most_usb.c:1125 Read of size 8 at addr ffff88807d259960 by task kworker/0:3/4193 CPU: 0 PID: 4193 Comm: kworker/0:3 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: usb_hub_wq hub_event Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 hdm_disconnect+0x109/0x1c0 drivers/most/most_usb.c:1125 usb_unbind_interface+0x1ee/0x860 drivers/usb/core/driver.c:458 __device_release_driver drivers/base/dd.c:1229 [inline] device_release_driver_internal+0x4b4/0x750 drivers/base/dd.c:1262 bus_remove_device+0x2e2/0x400 drivers/base/bus.c:531 device_del+0x628/0xa70 drivers/base/core.c:3600 usb_disable_device+0x3e2/0x890 drivers/usb/core/message.c:1414 usb_disconnect+0x348/0x8a0 drivers/usb/core/hub.c:2287 hub_port_connect drivers/usb/core/hub.c:5341 [inline] hub_port_connect_change drivers/usb/core/hub.c:5637 [inline] port_event drivers/usb/core/hub.c:5799 [inline] hub_event+0x1e9f/0x5560 drivers/usb/core/hub.c:5881 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 process_scheduled_works kernel/workqueue.c:2373 [inline] worker_thread+0xdca/0x12a0 kernel/workqueue.c:2459 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 4193: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:735 [inline] hdm_probe+0x8f/0x13d0 drivers/most/most_usb.c:959 usb_probe_interface+0x5a0/0xaf0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x175/0x200 drivers/base/bus.c:429 __device_attach+0x29b/0x460 drivers/base/dd.c:979 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3412 usb_set_configuration+0x1991/0x1fd0 drivers/usb/core/message.c:2165 usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238 usb_probe_device+0x139/0x270 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x175/0x200 drivers/base/bus.c:429 __device_attach+0x29b/0x460 drivers/base/dd.c:979 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3412 usb_new_device+0xd53/0x1640 drivers/usb/core/hub.c:2632 hub_port_connect drivers/usb/core/hub.c:5497 [inline] hub_port_connect_change drivers/usb/core/hub.c:5637 [inline] port_event drivers/usb/core/hub.c:5799 [inline] hub_event+0x2dd9/0x5560 drivers/usb/core/hub.c:5881 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Freed by task 4193: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 device_release+0x92/0x1c0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:713 [inline] kobject_release lib/kobject.c:744 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x21d/0x460 lib/kobject.c:761 hdm_disconnect+0xef/0x1c0 drivers/most/most_usb.c:1123 usb_unbind_interface+0x1ee/0x860 drivers/usb/core/driver.c:458 __device_release_driver drivers/base/dd.c:1229 [inline] device_release_driver_internal+0x4b4/0x750 drivers/base/dd.c:1262 bus_remove_device+0x2e2/0x400 drivers/base/bus.c:531 device_del+0x628/0xa70 drivers/base/core.c:3600 usb_disable_device+0x3e2/0x890 drivers/usb/core/message.c:1414 usb_disconnect+0x348/0x8a0 drivers/usb/core/hub.c:2287 hub_port_connect drivers/usb/core/hub.c:5341 [inline] hub_port_connect_change drivers/usb/core/hub.c:5637 [inline] port_event drivers/usb/core/hub.c:5799 [inline] hub_event+0x1e9f/0x5560 drivers/usb/core/hub.c:5881 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 process_scheduled_works kernel/workqueue.c:2373 [inline] worker_thread+0xdca/0x12a0 kernel/workqueue.c:2459 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 insert_work+0x54/0x3d0 kernel/workqueue.c:1366 __queue_work+0x9c5/0xd50 kernel/workqueue.c:1532 queue_work_on+0x11d/0x1d0 kernel/workqueue.c:1559 kref_put include/linux/kref.h:65 [inline] sg_release+0x1d0/0x2c0 drivers/scsi/sg.c:405 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff88807d258000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 6496 bytes inside of 8192-byte region [ffff88807d258000, ffff88807d25a000) The buggy address belongs to the page: page:ffffea0001f49600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7d258 head:ffffea0001f49600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea00007d2a00 0000000200000002 ffff888016842280 raw: 0000000000000000 0000000080020002 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x52a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 4190, ts 68529412011, free_ts 67601037485 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] __kmalloc+0x1cd/0x330 mm/slub.c:4408 kmalloc_array include/linux/slab.h:644 [inline] batadv_hash_new+0x77/0x290 net/batman-adv/hash.c:52 batadv_originator_init+0x50/0x1d0 net/batman-adv/originator.c:227 batadv_mesh_init+0x387/0x700 net/batman-adv/main.c:193 batadv_softif_init_late+0x9b6/0xe50 net/batman-adv/soft-interface.c:810 register_netdevice+0x612/0x16b0 net/core/dev.c:10327 __rtnl_newlink net/core/rtnetlink.c:3524 [inline] rtnl_newlink+0x114c/0x17d0 net/core/rtnetlink.c:3572 rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2507 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] __sys_sendto+0x423/0x580 net/socket.c:2063 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x94/0x280 mm/page_alloc.c:3396 put_page include/linux/mm.h:1258 [inline] __skb_frag_unref include/linux/skbuff.h:3254 [inline] skb_release_data+0x3fa/0x850 net/core/skbuff.c:672 skb_release_all net/core/skbuff.c:742 [inline] __kfree_skb+0x4c/0x60 net/core/skbuff.c:756 sk_eat_skb include/net/sock.h:2778 [inline] tcp_recvmsg_locked+0x14d5/0x2760 net/ipv4/tcp.c:2517 tcp_recvmsg+0x350/0x710 net/ipv4/tcp.c:2563 inet_recvmsg+0x136/0x1e0 net/ipv4/af_inet.c:868 sock_recvmsg_nosec net/socket.c:966 [inline] sock_recvmsg net/socket.c:984 [inline] sock_read_iter+0x2a2/0x340 net/socket.c:1057 call_read_iter include/linux/fs.h:2166 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x725/0xcf0 fs/read_write.c:485 ksys_read+0x14d/0x250 fs/read_write.c:623 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff88807d259800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807d259880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807d259900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807d259980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807d259a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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