udc dummy_udc.1: failed to start USB Gadget filesystem: -12 gadgetfs gadget.1: probe with driver gadgetfs failed with error -12 ================================================================== BUG: KASAN: slab-use-after-free in gadgetfs_bind+0xd8/0xad0 drivers/usb/gadget/legacy/inode.c:1692 Write of size 8 at addr ffff888079b5b8c0 by task syz.7.1152/10846 CPU: 0 UID: 0 PID: 10846 Comm: syz.7.1152 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 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 gadgetfs_bind+0xd8/0xad0 drivers/usb/gadget/legacy/inode.c:1692 gadget_bind_driver+0x2ca/0x9e0 drivers/usb/gadget/udc/core.c:1662 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x254/0xae0 drivers/base/dd.c:706 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898 __driver_attach+0x339/0x600 drivers/base/dd.c:1292 bus_for_each_dev+0x23b/0x2c0 drivers/base/bus.c:383 bus_add_driver+0x345/0x670 drivers/base/bus.c:763 driver_register+0x23a/0x320 drivers/base/driver.c:174 usb_gadget_register_driver_owner+0xf9/0x270 drivers/usb/gadget/udc/core.c:1752 dev_config+0xe3c/0x12a0 drivers/usb/gadget/legacy/inode.c:1893 vfs_write+0x296/0xba0 fs/read_write.c:685 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f57b8d9e159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f57b9c60028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f57b9025fa0 RCX: 00007f57b8d9e159 RDX: 000000000000001f RSI: 0000200000000400 RDI: 0000000000000008 RBP: 00007f57b8e3506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f57b9026038 R14: 00007f57b9025fa0 R15: 00007ffcab5d2f48 Allocated by task 5609: 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+0x321/0x600 mm/slub.c:5563 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] dev_new drivers/usb/gadget/legacy/inode.c:176 [inline] gadgetfs_fill_super+0x27b/0x790 drivers/usb/gadget/legacy/inode.c:2064 vfs_get_super fs/super.c:1391 [inline] get_tree_single+0xc0/0x150 fs/super.c:1418 vfs_get_tree+0x92/0x2a0 fs/super.c:1933 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3772 [inline] do_new_mount+0x319/0xdc0 fs/namespace.c:3848 do_mount fs/namespace.c:4181 [inline] __do_sys_mount fs/namespace.c:4397 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4374 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 10846: 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:2748 [inline] slab_free mm/slub.c:6508 [inline] kfree+0x1c5/0x650 mm/slub.c:6801 gadgetfs_bind+0x93c/0xad0 drivers/usb/gadget/legacy/inode.c:1713 gadget_bind_driver+0x2ca/0x9e0 drivers/usb/gadget/udc/core.c:1662 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x254/0xae0 drivers/base/dd.c:706 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898 __driver_attach+0x339/0x600 drivers/base/dd.c:1292 bus_for_each_dev+0x23b/0x2c0 drivers/base/bus.c:383 bus_add_driver+0x345/0x670 drivers/base/bus.c:763 driver_register+0x23a/0x320 drivers/base/driver.c:174 usb_gadget_register_driver_owner+0xf9/0x270 drivers/usb/gadget/udc/core.c:1752 dev_config+0xe3c/0x12a0 drivers/usb/gadget/legacy/inode.c:1893 vfs_write+0x296/0xba0 fs/read_write.c:685 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888079b5b800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 192 bytes inside of freed 1024-byte region [ffff888079b5b800, ffff888079b5bc00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x79b58 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 ffff88801b041dc0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b041dc0 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000003 fffffffffffffe01 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 5436, tgid 5436 (dhcpcd-run-hook), ts 57882251067 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+0x2209/0x2280 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436 alloc_slab_page mm/slub.c:3347 [inline] allocate_slab+0x7d/0x620 mm/slub.c:3462 new_slab mm/slub.c:3513 [inline] refill_objects+0x2d5/0x350 mm/slub.c:7417 refill_sheaf mm/slub.c:2885 [inline] __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4774 alloc_from_pcs mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:4984 [inline] __do_kmalloc_node mm/slub.c:5413 [inline] __kmalloc_noprof+0x47b/0x720 mm/slub.c:5439 _kmalloc_noprof include/linux/slab.h:995 [inline] load_elf_phdrs fs/binfmt_elf.c:537 [inline] load_elf_binary+0x2c6/0x28d0 fs/binfmt_elf.c:866 search_binary_handler fs/exec.c:1765 [inline] exec_binprm fs/exec.c:1797 [inline] bprm_execve+0x930/0x1590 fs/exec.c:1853 do_execveat_common+0x4f4/0x670 fs/exec.c:1951 __do_sys_execve fs/exec.c:2024 [inline] __se_sys_execve fs/exec.c:2018 [inline] __x64_sys_execve+0x97/0xc0 fs/exec.c:2018 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5273 tgid 5273 ts 57455607566 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2962 __slab_free+0x274/0x2c0 mm/slub.c:5823 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4683 [inline] slab_alloc_node mm/slub.c:4996 [inline] kmem_cache_alloc_node_noprof+0x354/0x610 mm/slub.c:5068 __alloc_skb+0x1db/0x7a0 net/core/skbuff.c:704 alloc_skb include/linux/skbuff.h:1384 [inline] alloc_skb_with_frags+0xc6/0x760 net/core/skbuff.c:6796 sock_alloc_send_pskb+0x878/0x990 net/core/sock.c:3015 unix_dgram_sendmsg+0x4da/0x17b0 net/unix/af_unix.c:2144 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] __sys_sendto+0x408/0x5a0 net/socket.c:2281 __do_sys_sendto net/socket.c:2288 [inline] __se_sys_sendto net/socket.c:2284 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2284 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888079b5b780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888079b5b800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888079b5b880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888079b5b900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888079b5b980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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