udc dummy_udc.0: failed to start USB Gadget filesystem: -12 gadgetfs: probe of gadget.0 failed with error -12 udc dummy_udc.1: failed to start USB Gadget filesystem: -12 gadgetfs: probe of gadget.1 failed with error -12 ================================================================== BUG: KASAN: use-after-free in gadgetfs_bind+0xcf/0x820 drivers/usb/gadget/legacy/inode.c:1677 Write of size 8 at addr ffff88807a23d0c0 by task syz.2.1688/10317 CPU: 0 PID: 10317 Comm: syz.2.1688 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 gadgetfs_bind+0xcf/0x820 drivers/usb/gadget/legacy/inode.c:1677 gadget_bind_driver+0x2af/0x760 drivers/usb/gadget/udc/core.c:1651 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x24a/0xb40 drivers/base/dd.c:638 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:804 driver_probe_device+0x4f/0x420 drivers/base/dd.c:834 __driver_attach+0x43d/0x6c0 drivers/base/dd.c:1220 bus_for_each_dev+0x182/0x1f0 drivers/base/bus.c:303 bus_add_driver+0x324/0x5d0 drivers/base/bus.c:620 driver_register+0x32d/0x430 drivers/base/driver.c:246 usb_gadget_register_driver_owner+0xf5/0x260 drivers/usb/gadget/udc/core.c:1730 dev_config+0xe45/0x1260 drivers/usb/gadget/legacy/inode.c:1878 vfs_write+0x2dc/0x9a0 fs/read_write.c:582 ksys_write+0x14d/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f9beb79e159 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:00007f9bec729028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f9beba25fa0 RCX: 00007f9beb79e159 RDX: 000000000000001f RSI: 0000200000000400 RDI: 0000000000000004 RBP: 00007f9beb835024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9beba26038 R14: 00007f9beba25fa0 R15: 00007ffe1fc08048 Allocated by task 4282: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] dev_new drivers/usb/gadget/legacy/inode.c:170 [inline] gadgetfs_fill_super+0x30d/0x610 drivers/usb/gadget/legacy/inode.c:2049 vfs_get_super fs/super.c:1222 [inline] get_tree_single+0xb5/0x160 fs/super.c:1260 vfs_get_tree+0x88/0x270 fs/super.c:1584 do_new_mount+0x247/0xa40 fs/namespace.c:3078 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 10317: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] __kmem_cache_free+0xb6/0x200 mm/slub.c:3700 gadgetfs_bind+0x6d2/0x820 drivers/usb/gadget/legacy/inode.c:1698 gadget_bind_driver+0x2af/0x760 drivers/usb/gadget/udc/core.c:1651 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x24a/0xb40 drivers/base/dd.c:638 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:804 driver_probe_device+0x4f/0x420 drivers/base/dd.c:834 __driver_attach+0x43d/0x6c0 drivers/base/dd.c:1220 bus_for_each_dev+0x182/0x1f0 drivers/base/bus.c:303 bus_add_driver+0x324/0x5d0 drivers/base/bus.c:620 driver_register+0x32d/0x430 drivers/base/driver.c:246 usb_gadget_register_driver_owner+0xf5/0x260 drivers/usb/gadget/udc/core.c:1730 dev_config+0xe45/0x1260 drivers/usb/gadget/legacy/inode.c:1878 vfs_write+0x2dc/0x9a0 fs/read_write.c:582 ksys_write+0x14d/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88807a23d000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 192 bytes inside of 1024-byte region [ffff88807a23d000, ffff88807a23d400) The buggy address belongs to the physical page: page:ffffea0001e88e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807a23b000 pfn:0x7a238 head:ffffea0001e88e00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000a34808 ffffea0001e81a08 ffff888017441dc0 raw: ffff88807a23b000 000000000010000d 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3646, tgid 3646 (udevd), ts 35227023934, free_ts 35109258680 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560 prep_new_page mm/page_alloc.c:2567 [inline] get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658 alloc_slab_page+0x5d/0x180 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2d0 mm/slub.c:1997 ___slab_alloc+0xbc5/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node_track_caller+0xa0/0x240 mm/slab_common.c:956 kmalloc_reserve net/core/skbuff.c:446 [inline] __alloc_skb+0x226/0x7d0 net/core/skbuff.c:515 alloc_skb include/linux/skbuff.h:1303 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline] netlink_sendmsg+0x654/0xbd0 net/netlink/af_netlink.c:1852 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5ed/0x9a0 net/socket.c:2519 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2573 __sys_sendmsg net/socket.c:2602 [inline] __do_sys_sendmsg net/socket.c:2611 [inline] __se_sys_sendmsg+0x1c3/0x2b0 net/socket.c:2609 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1487 [inline] free_pcp_prepare mm/page_alloc.c:1537 [inline] free_unref_page_prepare+0x8e5/0x9e0 mm/page_alloc.c:3414 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3509 free_slab mm/slub.c:2036 [inline] discard_slab mm/slub.c:2042 [inline] __unfreeze_partials+0x188/0x1e0 mm/slub.c:2591 put_cpu_partial+0x17c/0x250 mm/slub.c:2667 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x490 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] __kmem_cache_alloc_node+0x19d/0x270 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc+0xa3/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:699 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x28a/0x550 security/tomoyo/realpath.c:80 tomoyo_path_perm+0x382/0x610 security/tomoyo/file.c:831 tomoyo_path_symlink+0xa8/0xf0 security/tomoyo/tomoyo.c:199 security_path_symlink+0xdc/0x130 security/security.c:1202 do_symlinkat+0x10c/0x400 fs/namei.c:4546 __do_sys_symlink fs/namei.c:4573 [inline] __se_sys_symlink fs/namei.c:4571 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4571 Memory state around the buggy address: ffff88807a23cf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807a23d000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807a23d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807a23d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807a23d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================