usb 6-1: New USB device found, idVendor=0424, idProduct=c001, bcdDevice=cc.b0 usb 6-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 usb 6-1: Product: syz usb 6-1: Manufacturer: syz usb 6-1: SerialNumber: syz usb 6-1: USB disconnect, device number 8 ================================================================== BUG: KASAN: slab-use-after-free in hdm_disconnect+0x10d/0x1c0 drivers/most/most_usb.c:1125 Read of size 8 at addr ffff88805c941898 by task kworker/1:3/5861 CPU: 1 PID: 5861 Comm: kworker/1:3 Not tainted 6.6.100-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: usb_hub_wq hub_event Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xac/0x200 mm/kasan/report.c:466 kasan_report+0x117/0x150 mm/kasan/report.c:579 hdm_disconnect+0x10d/0x1c0 drivers/most/most_usb.c:1125 usb_unbind_interface+0x1f2/0x870 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:569 [inline] __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x4cb/0x7a0 drivers/base/dd.c:1295 bus_remove_device+0x342/0x400 drivers/base/bus.c:576 device_del+0x50b/0x900 drivers/base/core.c:3872 usb_disable_device+0x3e9/0x8a0 drivers/usb/core/message.c:1416 usb_disconnect+0x34c/0x8a0 drivers/usb/core/hub.c:2315 hub_port_connect drivers/usb/core/hub.c:5369 [inline] hub_port_connect_change drivers/usb/core/hub.c:5669 [inline] port_event drivers/usb/core/hub.c:5833 [inline] hub_event+0x1cef/0x49c0 drivers/usb/core/hub.c:5915 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Allocated by task 5861: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] hdm_probe+0x96/0x13e0 drivers/most/most_usb.c:959 usb_probe_interface+0x5a4/0xb00 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x25b/0xb40 drivers/base/dd.c:658 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:800 driver_probe_device+0x4f/0x420 drivers/base/dd.c:830 __device_attach_driver+0x2ca/0x520 drivers/base/dd.c:958 bus_for_each_drv+0x24b/0x2d0 drivers/base/bus.c:459 __device_attach+0x2b5/0x400 drivers/base/dd.c:1030 bus_probe_device+0x180/0x260 drivers/base/bus.c:534 device_add+0x85b/0xc20 drivers/base/core.c:3683 usb_set_configuration+0x1a79/0x20c0 drivers/usb/core/message.c:2207 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:238 usb_probe_device+0x13d/0x280 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x25b/0xb40 drivers/base/dd.c:658 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:800 driver_probe_device+0x4f/0x420 drivers/base/dd.c:830 __device_attach_driver+0x2ca/0x520 drivers/base/dd.c:958 bus_for_each_drv+0x24b/0x2d0 drivers/base/bus.c:459 __device_attach+0x2b5/0x400 drivers/base/dd.c:1030 bus_probe_device+0x180/0x260 drivers/base/bus.c:534 device_add+0x85b/0xc20 drivers/base/core.c:3683 usb_new_device+0xa31/0x1630 drivers/usb/core/hub.c:2660 hub_port_connect drivers/usb/core/hub.c:5529 [inline] hub_port_connect_change drivers/usb/core/hub.c:5669 [inline] port_event drivers/usb/core/hub.c:5833 [inline] hub_event+0x2962/0x49c0 drivers/usb/core/hub.c:5915 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Freed by task 5861: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1806 [inline] slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1832 slab_free mm/slub.c:3816 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3829 device_release+0x96/0x1c0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x221/0x470 lib/kobject.c:737 hdm_disconnect+0xf3/0x1c0 drivers/most/most_usb.c:1123 usb_unbind_interface+0x1f2/0x870 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:569 [inline] __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x4cb/0x7a0 drivers/base/dd.c:1295 bus_remove_device+0x342/0x400 drivers/base/bus.c:576 device_del+0x50b/0x900 drivers/base/core.c:3872 usb_disable_device+0x3e9/0x8a0 drivers/usb/core/message.c:1416 usb_disconnect+0x34c/0x8a0 drivers/usb/core/hub.c:2315 hub_port_connect drivers/usb/core/hub.c:5369 [inline] hub_port_connect_change drivers/usb/core/hub.c:5669 [inline] port_event drivers/usb/core/hub.c:5833 [inline] hub_event+0x1cef/0x49c0 drivers/usb/core/hub.c:5915 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 The buggy address belongs to the object at ffff88805c940000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 6296 bytes inside of freed 8192-byte region [ffff88805c940000, ffff88805c942000) The buggy address belongs to the physical page: page:ffffea0001725000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5c940 head:ffffea0001725000 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 ksm flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017842280 ffffea000092bc00 0000000000000003 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 0x1d2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 12412, tgid 12411 (syz.6.1405), ts 700172068230, free_ts 700161459917 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 alloc_slab_page+0x5d/0x170 mm/slub.c:1876 allocate_slab mm/slub.c:2023 [inline] new_slab+0x87/0x2e0 mm/slub.c:2076 ___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230 __slab_alloc mm/slub.c:3329 [inline] __slab_alloc_node mm/slub.c:3382 [inline] slab_alloc_node mm/slub.c:3475 [inline] __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027 kmalloc_reserve+0x117/0x260 net/core/skbuff.c:581 pskb_expand_head+0x185/0x1230 net/core/skbuff.c:2099 __pskb_pull_tail+0xb5/0x1790 net/core/skbuff.c:2661 pskb_may_pull_reason include/linux/skbuff.h:2677 [inline] pskb_may_pull include/linux/skbuff.h:2685 [inline] skb_ensure_writable+0x312/0x450 net/core/skbuff.c:5949 __bpf_try_make_writable net/core/filter.c:1673 [inline] sk_skb_try_make_writable net/core/filter.c:1896 [inline] ____sk_skb_pull_data net/core/filter.c:1910 [inline] sk_skb_pull_data+0x89/0xd0 net/core/filter.c:1899 0xffffffffa00007f6 bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline] __bpf_prog_run include/linux/filter.h:612 [inline] bpf_prog_run include/linux/filter.h:619 [inline] bpf_prog_run_pin_on_cpu include/linux/filter.h:636 [inline] sk_psock_verdict_recv+0x2aa/0x980 net/core/skmsg.c:1225 unix_stream_read_skb+0x11d/0x2d0 net/unix/af_unix.c:2709 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1154 [inline] free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429 discard_slab mm/slub.c:2122 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2662 put_cpu_partial+0x17c/0x250 mm/slub.c:2738 __slab_free+0x31d/0x410 mm/slub.c:3686 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3485 [inline] kmem_cache_alloc_node+0x150/0x330 mm/slub.c:3530 __alloc_skb+0x108/0x2c0 net/core/skbuff.c:640 alloc_skb include/linux/skbuff.h:1284 [inline] alloc_skb_with_frags+0xca/0x7c0 net/core/skbuff.c:6328 sock_alloc_send_pskb+0x857/0x990 net/core/sock.c:2799 unix_stream_sendmsg+0x476/0xba0 net/unix/af_unix.c:-1 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595 ___sys_sendmsg+0x220/0x290 net/socket.c:2649 Memory state around the buggy address: ffff88805c941780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805c941800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805c941880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805c941900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805c941980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================