================================================================== BUG: KASAN: slab-use-after-free in find_endpoint drivers/usb/gadget/udc/dummy_hcd.c:1602 [inline] BUG: KASAN: slab-use-after-free in dummy_timer+0xd0f/0x4b30 drivers/usb/gadget/udc/dummy_hcd.c:1874 Read of size 1 at addr ffff88805dbe2512 by task ktimers/0/16 CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 find_endpoint drivers/usb/gadget/udc/dummy_hcd.c:1602 [inline] dummy_timer+0xd0f/0x4b30 drivers/usb/gadget/udc/dummy_hcd.c:1874 __run_hrtimer kernel/time/hrtimer.c:2065 [inline] __hrtimer_run_queues+0x3eb/0xaf0 kernel/time/hrtimer.c:2122 hrtimer_run_softirq+0x18f/0x260 kernel/time/hrtimer.c:2139 handle_softirqs+0x1d9/0x6c0 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] run_ktimerd+0x69/0x100 kernel/softirq.c:1155 smpboot_thread_fn+0x57c/0xa80 kernel/smpboot.c:160 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 14250: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3cd/0x670 mm/slub.c:5486 _kmalloc_noprof include/linux/slab.h:969 [inline] _kzalloc_noprof include/linux/slab.h:1290 [inline] genradix_alloc_node include/linux/generic-radix-tree.h:101 [inline] __genradix_ptr_alloc+0x352/0x4a0 lib/generic-radix-tree.c:69 __genradix_prealloc+0x44/0x90 lib/generic-radix-tree.c:216 sctp_stream_alloc_out+0x7a/0x100 net/sctp/stream.c:104 sctp_send_add_streams+0x1d6/0x400 net/sctp/stream.c:455 sctp_setsockopt+0x7b9/0x12c0 net/sctp/socket.c:4753 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2408 __sys_setsockopt net/socket.c:2433 [inline] __do_sys_setsockopt net/socket.c:2439 [inline] __se_sys_setsockopt net/socket.c:2436 [inline] __x64_sys_setsockopt+0x143/0x1b0 net/socket.c:2436 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 14249: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2706 [inline] slab_free mm/slub.c:6388 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6703 genradix_free_recurse+0x5d/0xa0 lib/generic-radix-tree.c:204 genradix_free_recurse+0x5d/0xa0 lib/generic-radix-tree.c:204 sctp_stream_free+0x262/0x2a0 net/sctp/stream.c:191 sctp_association_free+0x26d/0x7f0 net/sctp/associola.c:351 sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:950 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1336 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1204 [inline] sctp_do_sm+0x3fce/0x5d50 net/sctp/sm_sideeffect.c:1175 sctp_primitive_ABORT+0x98/0xc0 net/sctp/primitive.c:104 sctp_close+0x2cf/0x950 net/sctp/socket.c:1527 inet_release+0x143/0x190 net/ipv4/af_inet.c:442 __sock_release+0xa0/0x1f0 net/socket.c:739 sock_close+0x1c/0x30 net/socket.c:1541 __fput+0x42a/0xa80 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:339 [inline] do_syscall_64+0x33d/0x530 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88805dbe2400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 274 bytes inside of freed 512-byte region [ffff88805dbe2400, ffff88805dbe2600) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5dbe0 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813fe37c80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813fe37c80 dead000000000100 dead000000000122 head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 0080000000000002 ffffffffffffff01 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3332, tgid 3332 (kworker/u8:24), ts 91294214911 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x264c/0x26c0 mm/page_alloc.c:3955 __alloc_frozen_pages_noprof+0x222/0x5b0 mm/page_alloc.c:5394 alloc_slab_page mm/slub.c:3295 [inline] allocate_slab+0x7c/0x5e0 mm/slub.c:3410 new_slab mm/slub.c:3456 [inline] refill_objects+0x2d8/0x350 mm/slub.c:7321 refill_sheaf mm/slub.c:2833 [inline] __pcs_replace_empty_main+0x330/0x690 mm/slub.c:4699 alloc_from_pcs mm/slub.c:4775 [inline] slab_alloc_node mm/slub.c:4909 [inline] __do_kmalloc_node mm/slub.c:5338 [inline] __kmalloc_noprof+0x543/0x790 mm/slub.c:5364 _kmalloc_noprof include/linux/slab.h:973 [inline] _kzalloc_noprof include/linux/slab.h:1290 [inline] fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x149/0x890 net/ipv6/route.c:3833 ip6_route_add+0x49/0x1d0 net/ipv6/route.c:3962 addrconf_prefix_route+0x3a2/0x480 net/ipv6/addrconf.c:2504 addrconf_add_linklocal+0x262/0x490 net/ipv6/addrconf.c:3336 addrconf_addr_gen+0x2f8/0x360 net/ipv6/addrconf.c:3470 addrconf_notify+0xb1e/0x1050 net/ipv6/addrconf.c:3775 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85 netif_state_change+0x27d/0x3a0 net/core/dev.c:1603 page_owner free stack trace missing Memory state around the buggy address: ffff88805dbe2400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805dbe2480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805dbe2500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805dbe2580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805dbe2600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================