==================================================================
BUG: KASAN: use-after-free in gphonet_set_gadget drivers/usb/gadget/function/f_phonet.c:720 [inline]
BUG: KASAN: use-after-free in pn_bind+0xe4/0x550 drivers/usb/gadget/function/f_phonet.c:510
Write of size 8 at addr ffff0000f4bf47f8 by task syz.0.1004/9681

CPU: 0 UID: 0 PID: 9681 Comm: syz.0.1004 Tainted: G             L      syzkaller #0 PREEMPT 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 print_address_description+0xb0/0x238 mm/kasan/report.c:378
 print_report+0x68/0x84 mm/kasan/report.c:482
 kasan_report+0x8c/0xc4 mm/kasan/report.c:595
 __asan_report_store8_noabort+0x20/0x2c mm/kasan/report_generic.c:386
 gphonet_set_gadget drivers/usb/gadget/function/f_phonet.c:720 [inline]
 pn_bind+0xe4/0x550 drivers/usb/gadget/function/f_phonet.c:510
 usb_add_function+0x1d0/0x6bc drivers/usb/gadget/composite.c:333
 configfs_composite_bind+0xb4c/0x10b8 drivers/usb/gadget/configfs.c:1802
 gadget_bind_driver+0x274/0x834 drivers/usb/gadget/udc/core.c:1662
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x29c/0x800 drivers/base/dd.c:706
 __driver_probe_device+0x1e0/0x350 drivers/base/dd.c:868
 driver_probe_device+0x6c/0x19c drivers/base/dd.c:898
 __driver_attach+0x168/0x384 drivers/base/dd.c:1292
 bus_for_each_dev+0x128/0x1b4 drivers/base/bus.c:383
 driver_attach+0x50/0x60 drivers/base/dd.c:1310
 bus_add_driver+0x208/0x500 drivers/base/bus.c:763
 driver_register+0x220/0x310 drivers/base/driver.c:174
 usb_gadget_register_driver_owner+0xf0/0x25c drivers/usb/gadget/udc/core.c:1752
 gadget_dev_desc_UDC_store+0x164/0x22c drivers/usb/gadget/configfs.c:300
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x27c/0x354 fs/configfs/file.c:229
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x51c/0xa0c fs/read_write.c:687
 ksys_write+0x12c/0x228 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:747
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x134bf4
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 0000000000000000 fffffdffc3d2fd08 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000f4bf4680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000f4bf4700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff0000f4bf4780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                                ^
 ffff0000f4bf4800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000f4bf4880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
------------[ cut here ]------------
kernel BUG at net/core/dev.c:11341!
Internal error: Oops - BUG: 00000000f2000800 [#1]  SMP
Modules linked in:
CPU: 0 UID: 0 PID: 9681 Comm: syz.0.1004 Tainted: G    B        L      syzkaller #0 PREEMPT 
Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : register_netdevice+0x145c/0x14b8 net/core/dev.c:11341
lr : register_netdevice+0x145c/0x14b8 net/core/dev.c:11341
sp : ffff800092627400
x29: ffff8000926274f0 x28: 1fffe0001e6d3416 x27: dfff800000000000
x26: ffff7000124c4e88 x25: ffff0000f4bf4000 x24: 0000000000000000
x23: 1fffe0001e97e8f1 x22: ffff0000c8650c00 x21: 0000000000000000
x20: ffff0000f4bf4788 x19: ffff0000f4bf4000 x18: 1fffe00035bc5428
x17: 0000000000000003 x16: ffff800088b07000 x15: ffff800088bbd060
x14: ffff0001ade2a14c x13: 0000000000000001 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000080000 x9 : 0000000000011a58
x8 : ffff800097f1a000 x7 : 0000000000000000 x6 : ffff80008045f464
x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800084c9a754
x2 : 0000000000000000 x1 : ffff0000f733d7c0 x0 : 0000000000000001
Call trace:
 register_netdevice+0x145c/0x14b8 net/core/dev.c:11341 (P)
 register_netdev+0x4c/0x68 net/core/dev.c:11562
 gphonet_register_netdev drivers/usb/gadget/function/f_phonet.c:727 [inline]
 pn_bind+0xf4/0x550 drivers/usb/gadget/function/f_phonet.c:511
 usb_add_function+0x1d0/0x6bc drivers/usb/gadget/composite.c:333
 configfs_composite_bind+0xb4c/0x10b8 drivers/usb/gadget/configfs.c:1802
 gadget_bind_driver+0x274/0x834 drivers/usb/gadget/udc/core.c:1662
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x29c/0x800 drivers/base/dd.c:706
 __driver_probe_device+0x1e0/0x350 drivers/base/dd.c:868
 driver_probe_device+0x6c/0x19c drivers/base/dd.c:898
 __driver_attach+0x168/0x384 drivers/base/dd.c:1292
 bus_for_each_dev+0x128/0x1b4 drivers/base/bus.c:383
 driver_attach+0x50/0x60 drivers/base/dd.c:1310
 bus_add_driver+0x208/0x500 drivers/base/bus.c:763
 driver_register+0x220/0x310 drivers/base/driver.c:174
 usb_gadget_register_driver_owner+0xf0/0x25c drivers/usb/gadget/udc/core.c:1752
 gadget_dev_desc_UDC_store+0x164/0x22c drivers/usb/gadget/configfs.c:300
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x27c/0x354 fs/configfs/file.c:229
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x51c/0xa0c fs/read_write.c:687
 ksys_write+0x12c/0x228 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:747
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594
Code: d4210000 96e6eb81 d4210000 96e6eb7f (d4210000) 
---[ end trace 0000000000000000 ]---