==================================================================
BUG: KASAN: slab-use-after-free in gphonet_set_gadget drivers/usb/gadget/function/f_phonet.c:720 [inline]
BUG: KASAN: slab-use-after-free in pn_bind+0x106/0xb10 drivers/usb/gadget/function/f_phonet.c:510
Write of size 8 at addr ffff88802f1966e8 by task syz.0.709/9043

CPU: 0 PID: 9043 Comm: syz.0.709 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 gphonet_set_gadget drivers/usb/gadget/function/f_phonet.c:720 [inline]
 pn_bind+0x106/0xb10 drivers/usb/gadget/function/f_phonet.c:510
 usb_add_function+0x2dd/0x980 drivers/usb/gadget/composite.c:333
 configfs_composite_bind+0xde4/0x13f0 drivers/usb/gadget/configfs.c:1800
 gadget_bind_driver+0x2b3/0x770 drivers/usb/gadget/udc/core.c:1651
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x247/0xae0 drivers/base/dd.c:717
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:879
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:909
 __driver_attach+0x444/0x6d0 drivers/base/dd.c:1295
 bus_for_each_dev+0x235/0x2b0 drivers/base/bus.c:370
 bus_add_driver+0x340/0x630 drivers/base/bus.c:723
 driver_register+0x23a/0x310 drivers/base/driver.c:246
 usb_gadget_register_driver_owner+0xf9/0x270 drivers/usb/gadget/udc/core.c:1730
 gadget_dev_desc_UDC_store+0x1c7/0x2e0 drivers/usb/gadget/configfs.c:300
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x312/0x400 fs/configfs/file.c:229
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x474/0x9a0 fs/read_write.c:584
 ksys_write+0x151/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f47b959df99
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:00007f47ba48b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f47b9825fa0 RCX: 00007f47b959df99
RDX: 000000000000000c RSI: 0000200000001100 RDI: 0000000000000003
RBP: 00007f47b9634ec4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f47b9826038 R14: 00007f47b9825fa0 R15: 00007fff006ff0b8
 </TASK>

Allocated by task 6535:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1007 [inline]
 __kmalloc_node+0xb6/0x240 mm/slab_common.c:1014
 kmalloc_node include/linux/slab.h:620 [inline]
 kvmalloc_node+0x70/0x180 mm/util.c:617
 kvmalloc include/linux/slab.h:738 [inline]
 kvzalloc include/linux/slab.h:746 [inline]
 alloc_netdev_mqs+0x87/0x1040 net/core/dev.c:10867
 gphonet_setup_default drivers/usb/gadget/function/f_phonet.c:706 [inline]
 phonet_alloc_inst+0xa4/0x180 drivers/usb/gadget/function/f_phonet.c:640
 try_get_usb_function_instance drivers/usb/gadget/functions.c:28 [inline]
 usb_get_function_instance+0xdd/0x2e0 drivers/usb/gadget/functions.c:44
 function_make+0x11c/0x350 drivers/usb/gadget/configfs.c:625
 configfs_mkdir+0x515/0x9e0 fs/configfs/dir.c:1360
 vfs_mkdir+0x2a5/0x470 fs/namei.c:4125
 do_mkdirat+0x1dc/0x450 fs/namei.c:4148
 __do_sys_mkdirat fs/namei.c:4163 [inline]
 __se_sys_mkdirat fs/namei.c:4161 [inline]
 __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4161
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 8933:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843
 gphonet_register_netdev drivers/usb/gadget/function/f_phonet.c:729 [inline]
 pn_bind+0x131/0xb10 drivers/usb/gadget/function/f_phonet.c:511
 usb_add_function+0x2dd/0x980 drivers/usb/gadget/composite.c:333
 configfs_composite_bind+0xde4/0x13f0 drivers/usb/gadget/configfs.c:1800
 gadget_bind_driver+0x2b3/0x770 drivers/usb/gadget/udc/core.c:1651
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x247/0xae0 drivers/base/dd.c:717
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:879
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:909
 __driver_attach+0x444/0x6d0 drivers/base/dd.c:1295
 bus_for_each_dev+0x235/0x2b0 drivers/base/bus.c:370
 bus_add_driver+0x340/0x630 drivers/base/bus.c:723
 driver_register+0x23a/0x310 drivers/base/driver.c:246
 usb_gadget_register_driver_owner+0xf9/0x270 drivers/usb/gadget/udc/core.c:1730
 gadget_dev_desc_UDC_store+0x1c7/0x2e0 drivers/usb/gadget/configfs.c:300
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x312/0x400 fs/configfs/file.c:229
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x474/0x9a0 fs/read_write.c:584
 ksys_write+0x151/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff88802f196000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 1768 bytes inside of
 freed 4096-byte region [ffff88802f196000, ffff88802f197000)

The buggy address belongs to the physical page:
page:ffffea0000bc6400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802f192000 pfn:0x2f190
head:ffffea0000bc6400 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888060bea941
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017c4f500 ffffea0001971410 ffffea00015d8e10
raw: ffff88802f192000 0000000000040001 00000001ffffffff ffff888060bea941
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5141, tgid 5141 (udevd), ts 128560223648, free_ts 128397983021
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1582
 prep_new_page mm/page_alloc.c:1589 [inline]
 get_page_from_freelist+0x2181/0x22a0 mm/page_alloc.c:3221
 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501
 alloc_slab_page+0x5d/0x180 mm/slub.c:1881
 allocate_slab mm/slub.c:2028 [inline]
 new_slab+0x87/0x2d0 mm/slub.c:2081
 ___slab_alloc+0xc5c/0x12f0 mm/slub.c:3253
 __slab_alloc mm/slub.c:3339 [inline]
 __slab_alloc_node mm/slub.c:3392 [inline]
 slab_alloc_node mm/slub.c:3485 [inline]
 __kmem_cache_alloc_node+0x11f/0x250 mm/slub.c:3534
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc_node+0xa6/0x240 mm/slab_common.c:1014
 kmalloc_node include/linux/slab.h:620 [inline]
 kvmalloc_node+0x70/0x180 mm/util.c:617
 kvmalloc include/linux/slab.h:738 [inline]
 seq_buf_alloc fs/seq_file.c:38 [inline]
 seq_read_iter+0x1e2/0xc50 fs/seq_file.c:210
 call_read_iter include/linux/fs.h:2012 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x486/0x990 fs/read_write.c:470
 ksys_read+0x151/0x260 fs/read_write.c:613
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 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:1182 [inline]
 free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2459
 discard_slab mm/slub.c:2127 [inline]
 __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667
 put_cpu_partial+0x17c/0x250 mm/slub.c:2743
 __slab_free+0x319/0x400 mm/slub.c:3700
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6a/0x4d0 mm/slab.h:770
 slab_alloc_node mm/slub.c:3495 [inline]
 slab_alloc mm/slub.c:3503 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3510 [inline]
 kmem_cache_alloc+0x17e/0x2c0 mm/slub.c:3519
 ptlock_alloc+0x20/0x70 mm/memory.c:6177
 ptlock_init include/linux/mm.h:2964 [inline]
 pagetable_pte_ctor include/linux/mm.h:2987 [inline]
 __pte_alloc_one include/asm-generic/pgalloc.h:71 [inline]
 pte_alloc_one+0xcc/0x540 arch/x86/mm/pgtable.c:33
 __pte_alloc+0x22/0x2a0 mm/memory.c:438
 copy_pte_range mm/memory.c:1029 [inline]
 copy_pmd_range mm/memory.c:1168 [inline]
 copy_pud_range mm/memory.c:1205 [inline]
 copy_p4d_range mm/memory.c:1229 [inline]
 copy_page_range+0x2dca/0x3700 mm/memory.c:1323
 dup_mmap kernel/fork.c:769 [inline]
 dup_mm kernel/fork.c:1700 [inline]
 copy_mm+0x1751/0x1e30 kernel/fork.c:1749
 copy_process+0x16c9/0x3da0 kernel/fork.c:2510

Memory state around the buggy address:
 ffff88802f196580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802f196600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802f196680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff88802f196700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802f196780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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