================================================================== BUG: KASAN: use-after-free in kobject_get+0x113/0x120 lib/kobject.c:663 Read of size 1 at addr ffff88811453b83c by task syz.7.1757/6614 CPU: 1 PID: 6614 Comm: syz.7.1757 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x100/0x140 mm/kasan/report.c:452 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306 kobject_get+0x113/0x120 lib/kobject.c:663 get_device drivers/base/core.c:3361 [inline] device_add+0x331/0xc00 drivers/base/core.c:3191 device_create_groups_vargs drivers/base/core.c:3960 [inline] device_create+0x26c/0x300 drivers/base/core.c:4002 create_function_device+0x60/0x70 drivers/usb/gadget/configfs.c:31 create_alsa_device drivers/usb/gadget/function/f_midi.c:1262 [inline] f_midi_alloc_inst+0x1a8/0x380 drivers/usb/gadget/function/f_midi.c:1303 try_get_usb_function_instance drivers/usb/gadget/functions.c:28 [inline] usb_get_function_instance+0xe2/0x2f0 drivers/usb/gadget/functions.c:44 function_make+0x118/0x350 drivers/usb/gadget/configfs.c:636 configfs_mkdir+0x5d2/0xd90 fs/configfs/dir.c:1354 vfs_mkdir+0x42c/0x600 fs/namei.c:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fd1ac6420d9 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:00007fd1ab09b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fd1ac8c9fa0 RCX: 00007fd1ac6420d9 RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007fd1ac6d9024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd1ac8ca038 R14: 00007fd1ac8c9fa0 R15: 00007fff32b8ac78 Allocated by task 6046: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] ____kasan_kmalloc mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] kmem_cache_alloc_trace+0x179/0x2e0 mm/slub.c:2979 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:667 [inline] device_create_groups_vargs drivers/base/core.c:3942 [inline] device_create+0x13a/0x300 drivers/base/core.c:4002 android_device_create drivers/usb/gadget/configfs.c:1789 [inline] gadgets_make+0x816/0xa70 drivers/usb/gadget/configfs.c:1886 configfs_mkdir+0x5d2/0xd90 fs/configfs/dir.c:1354 vfs_mkdir+0x42c/0x600 fs/namei.c:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff88811453b800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 60 bytes inside of 1024-byte region [ffff88811453b800, ffff88811453bc00) The buggy address belongs to the page: page:ffffea0004514e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88811453b800 pfn:0x114538 head:ffffea0004514e00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea00046a0a08 ffffea000446d208 ffff888100042f00 raw: ffff88811453b800 0000000000100005 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 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 367, ts 88442039197, free_ts 88431954796 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x176/0x190 mm/page_alloc.c:2462 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2f8/0x4c0 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] __kmalloc_track_caller+0x1e4/0x310 mm/slub.c:4541 __kmalloc_reserve net/core/skbuff.c:144 [inline] __alloc_skb+0xdc/0x520 net/core/skbuff.c:212 alloc_skb include/linux/skbuff.h:1126 [inline] nlmsg_new include/net/netlink.h:953 [inline] inet6_rt_notify+0x293/0x480 net/ipv6/route.c:6053 fib6_add_rt2node net/ipv6/ip6_fib.c:1253 [inline] fib6_add+0x2174/0x3c60 net/ipv6/ip6_fib.c:1482 __ip6_ins_rt net/ipv6/route.c:1304 [inline] ip6_ins_rt+0xd3/0x130 net/ipv6/route.c:1314 __ipv6_ifa_notify+0x4df/0xe70 net/ipv6/addrconf.c:6160 ipv6_ifa_notify net/ipv6/addrconf.c:6200 [inline] addrconf_dad_completed+0x18c/0xe30 net/ipv6/addrconf.c:4247 addrconf_dad_work+0xc5f/0x1480 net/ipv6/addrconf.c:-1 process_one_work+0x6fd/0xbc0 kernel/workqueue.c:2301 worker_thread+0xa8e/0x13c0 kernel/workqueue.c:2447 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] __free_pages_ok+0x80b/0x830 mm/page_alloc.c:1629 free_the_page mm/page_alloc.c:5445 [inline] __free_pages+0xd8/0x390 mm/page_alloc.c:5454 __free_slab+0xcf/0x190 mm/slub.c:1899 free_slab mm/slub.c:1914 [inline] discard_slab mm/slub.c:1920 [inline] unfreeze_partials+0x150/0x180 mm/slub.c:2415 put_cpu_partial+0xc1/0x180 mm/slub.c:2451 __slab_free+0x2c9/0x3a0 mm/slub.c:3100 do_slab_free mm/slub.c:3196 [inline] ___cache_free+0x10e/0x130 mm/slub.c:3215 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:440 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580 slab_alloc_node mm/slub.c:2952 [inline] slab_alloc mm/slub.c:2960 [inline] __kmalloc+0x17b/0x330 mm/slub.c:4034 kmalloc include/linux/slab.h:560 [inline] kzalloc include/linux/slab.h:667 [inline] fib_create_info+0x8eb/0x1ed0 net/ipv4/fib_semantics.c:1477 fib_table_insert+0xc2/0x1d50 net/ipv4/fib_trie.c:1170 fib_magic net/ipv4/fib_frontend.c:1107 [inline] fib_add_ifaddr+0x360/0xf90 net/ipv4/fib_frontend.c:1129 Memory state around the buggy address: ffff88811453b700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88811453b780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88811453b800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811453b880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811453b900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 6614 at lib/refcount.c:25 refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25 Modules linked in: CPU: 0 PID: 6614 Comm: syz.7.1757 Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25 Code: 04 01 48 c7 c7 e0 48 40 85 e8 b8 d3 3a 02 0f 0b eb df e8 9f 92 26 ff c6 05 3c 80 82 04 01 48 c7 c7 20 48 40 85 e8 9c d3 3a 02 <0f> 0b eb c3 e8 83 92 26 ff c6 05 21 80 82 04 01 48 c7 c7 80 48 40 RSP: 0018:ffffc90000d97950 EFLAGS: 00010246 RAX: a7890ace0df79a00 RBX: 0000000000000002 RCX: 0000000000080000 RDX: ffffc9000c338000 RSI: 0000000000073891 RDI: 0000000000073892 RBP: ffffc90000d97960 R08: ffffc90000d972e7 R09: fffff520001b2e90 R10: dffffc0000000000 R11: fffff520001b2e5d R12: 0000000000000000 R13: ffff8881269eb068 R14: 0000000000000002 R15: 0000000000000000 FS: 00007fd1ab09b6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3ee2739d58 CR3: 0000000111e4f000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_add include/linux/refcount.h:-1 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] kref_get include/linux/kref.h:45 [inline] kobject_get+0xfb/0x120 lib/kobject.c:667 get_device drivers/base/core.c:3361 [inline] device_add+0x331/0xc00 drivers/base/core.c:3191 device_create_groups_vargs drivers/base/core.c:3960 [inline] device_create+0x26c/0x300 drivers/base/core.c:4002 create_function_device+0x60/0x70 drivers/usb/gadget/configfs.c:31 create_alsa_device drivers/usb/gadget/function/f_midi.c:1262 [inline] f_midi_alloc_inst+0x1a8/0x380 drivers/usb/gadget/function/f_midi.c:1303 try_get_usb_function_instance drivers/usb/gadget/functions.c:28 [inline] usb_get_function_instance+0xe2/0x2f0 drivers/usb/gadget/functions.c:44 function_make+0x118/0x350 drivers/usb/gadget/configfs.c:636 configfs_mkdir+0x5d2/0xd90 fs/configfs/dir.c:1354 vfs_mkdir+0x42c/0x600 fs/namei.c:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fd1ac6420d9 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:00007fd1ab09b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fd1ac8c9fa0 RCX: 00007fd1ac6420d9 RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007fd1ac6d9024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd1ac8ca038 R14: 00007fd1ac8c9fa0 R15: 00007fff32b8ac78 ---[ end trace 559e19d0d293c92b ]--- ------------[ cut here ]------------ refcount_t: saturated; leaking memory. WARNING: CPU: 1 PID: 6614 at lib/refcount.c:22 refcount_warn_saturate+0x158/0x1a0 lib/refcount.c:22 Modules linked in: CPU: 1 PID: 6614 Comm: syz.7.1757 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:refcount_warn_saturate+0x158/0x1a0 lib/refcount.c:22 Code: 04 01 48 c7 c7 a0 47 40 85 e8 64 d3 3a 02 0f 0b eb 8b e8 4b 92 26 ff c6 05 e7 7f 82 04 01 48 c7 c7 a0 47 40 85 e8 48 d3 3a 02 <0f> 0b e9 6c ff ff ff e8 2c 92 26 ff c6 05 cc 7f 82 04 01 48 c7 c7 RSP: 0018:ffffc90000d97818 EFLAGS: 00010246 RAX: a7890ace0df79a00 RBX: 0000000000000001 RCX: 0000000000080000 RDX: ffffc9000c338000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90000d97828 R08: ffff8881f7152fbf R09: 1ffff1103ee2a5f7 R10: dffffc0000000000 R11: ffffed103ee2a5f8 R12: 00000000c0000000 R13: ffff8881269eb018 R14: 0000000000000001 R15: ffff88811453b838 FS: 00007fd1ab09b6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3ee2739d58 CR3: 0000000111e4f000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_add include/linux/refcount.h:-1 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] kref_get include/linux/kref.h:45 [inline] kobject_get lib/kobject.c:667 [inline] kobject_add_internal+0xc44/0xde0 lib/kobject.c:248 kobject_add_varg lib/kobject.c:398 [inline] kobject_add+0x165/0x230 lib/kobject.c:450 device_add+0x3d8/0xc00 drivers/base/core.c:3206 device_create_groups_vargs drivers/base/core.c:3960 [inline] device_create+0x26c/0x300 drivers/base/core.c:4002 create_function_device+0x60/0x70 drivers/usb/gadget/configfs.c:31 create_alsa_device drivers/usb/gadget/function/f_midi.c:1262 [inline] f_midi_alloc_inst+0x1a8/0x380 drivers/usb/gadget/function/f_midi.c:1303 try_get_usb_function_instance drivers/usb/gadget/functions.c:28 [inline] usb_get_function_instance+0xe2/0x2f0 drivers/usb/gadget/functions.c:44 function_make+0x118/0x350 drivers/usb/gadget/configfs.c:636 configfs_mkdir+0x5d2/0xd90 fs/configfs/dir.c:1354 vfs_mkdir+0x42c/0x600 fs/namei.c:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fd1ac6420d9 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:00007fd1ab09b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fd1ac8c9fa0 RCX: 00007fd1ac6420d9 RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007fd1ac6d9024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd1ac8ca038 R14: 00007fd1ac8c9fa0 R15: 00007fff32b8ac78 ---[ end trace 559e19d0d293c92c ]--- ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 6614 at lib/refcount.c:28 refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28 Modules linked in: CPU: 1 PID: 6614 Comm: syz.7.1757 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28 Code: 04 01 48 c7 c7 20 48 40 85 e8 9c d3 3a 02 0f 0b eb c3 e8 83 92 26 ff c6 05 21 80 82 04 01 48 c7 c7 80 48 40 85 e8 80 d3 3a 02 <0f> 0b eb a7 e8 67 92 26 ff c6 05 02 80 82 04 01 48 c7 c7 a0 47 40 RSP: 0018:ffffc90000d977e0 EFLAGS: 00010246 RAX: a7890ace0df79a00 RBX: 0000000000000003 RCX: 0000000000080000 RDX: ffffc9000c338000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90000d977f0 R08: ffff8881f7152fbf R09: 1ffff1103ee2a5f7 R10: dffffc0000000000 R11: ffffed103ee2a5f8 R12: 00000000c0000000 R13: ffff88811453b83c R14: 0000000000000003 R15: ffff88811453b838 FS: 00007fd1ab09b6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3ee2739d58 CR3: 0000000111e4f000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] kref_put include/linux/kref.h:64 [inline] kobject_put+0x231/0x270 lib/kobject.c:761 kobject_add_internal+0xb52/0xde0 lib/kobject.c:266 kobject_add_varg lib/kobject.c:398 [inline] kobject_add+0x165/0x230 lib/kobject.c:450 device_add+0x3d8/0xc00 drivers/base/core.c:3206 device_create_groups_vargs drivers/base/core.c:3960 [inline] device_create+0x26c/0x300 drivers/base/core.c:4002 create_function_device+0x60/0x70 drivers/usb/gadget/configfs.c:31 create_alsa_device drivers/usb/gadget/function/f_midi.c:1262 [inline] f_midi_alloc_inst+0x1a8/0x380 drivers/usb/gadget/function/f_midi.c:1303 try_get_usb_function_instance drivers/usb/gadget/functions.c:28 [inline] usb_get_function_instance+0xe2/0x2f0 drivers/usb/gadget/functions.c:44 function_make+0x118/0x350 drivers/usb/gadget/configfs.c:636 configfs_mkdir+0x5d2/0xd90 fs/configfs/dir.c:1354 vfs_mkdir+0x42c/0x600 fs/namei.c:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fd1ac6420d9 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:00007fd1ab09b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fd1ac8c9fa0 RCX: 00007fd1ac6420d9 RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007fd1ac6d9024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd1ac8ca038 R14: 00007fd1ac8c9fa0 R15: 00007fff32b8ac78 ---[ end trace 559e19d0d293c92d ]--- kobject_add_internal failed for f_midi (error: -2 parent: ` 7)