[syzbot] [usb?] BUG: spinlock bad magic in gadget_dev_open

Hello,

syzbot found the following issue on:

HEAD commit:    3d6d817622b0 Merge tag 'scsi-fixes' of git://git.kernel.or..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=114ccc79580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c44651ea7dd2f307
dashboard link: https://syzkaller.appspot.com/bug?extid=7659afffb6c3d2d12b83
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-3d6d8176.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f486efba4dfc/vmlinux-3d6d8176.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9b9dcf9ee9f3/bzImage-3d6d8176.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

BUG: spinlock bad magic on CPU#3, syz.3.498/7450
==================================================================
BUG: KASAN: slab-out-of-bounds in task_pid_nr include/linux/pid.h:236 [inline]
BUG: KASAN: slab-out-of-bounds in spin_dump+0xe7/0x160 kernel/locking/spinlock_debug.c:64
Read of size 4 at addr ffff8880584fbe50 by task syz.3.498/7450

CPU: 3 UID: 0 PID: 7450 Comm: syz.3.498 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
 task_pid_nr include/linux/pid.h:236 [inline]
 spin_dump+0xe7/0x160 kernel/locking/spinlock_debug.c:64
 spin_bug kernel/locking/spinlock_debug.c:78 [inline]
 debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline]
 do_raw_spin_lock.cold+0x37/0x3c kernel/locking/spinlock_debug.c:115
 spin_lock_irq include/linux/spinlock.h:372 [inline]
 gadget_dev_open+0x44/0x1b0 drivers/usb/gadget/legacy/inode.c:1919
 do_dentry_open+0x6ab/0x14d0 fs/open.c:947
 vfs_open+0x82/0x3f0 fs/open.c:1052
 do_open fs/namei.c:4700 [inline]
 path_openat+0x2873/0x4280 fs/namei.c:4863
 do_file_open+0x20e/0x430 fs/namei.c:4892
 do_sys_openat2+0x10f/0x1e0 fs/open.c:1368
 do_sys_open fs/open.c:1374 [inline]
 __do_sys_openat fs/open.c:1390 [inline]
 __se_sys_openat fs/open.c:1385 [inline]
 __x64_sys_openat+0x12d/0x210 fs/open.c:1385
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff73279e0d9
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:00007ff7335f1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ff732a25fa0 RCX: 00007ff73279e0d9
RDX: 0000000000000002 RSI: 00002000000001c0 RDI: ffffffffffffff9c
RBP: 00007ff732835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff732a26038 R14: 00007ff732a25fa0 R15: 00007ffcdadf0c88
 </TASK>

Allocated by task 7177:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5334 [inline]
 __kvmalloc_node_noprof+0x34f/0x970 mm/slub.c:6905
 bucket_table_alloc.isra.0+0x88/0x460 lib/rhashtable.c:194
 __rhashtable_init_noprof+0x43a/0x890 lib/rhashtable.c:1212
 ioam6_net_init+0xb8/0x190 net/ipv6/ioam6.c:992
 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
 setup_net+0x118/0x3a0 net/core/net_namespace.c:446
 copy_net_ns+0x46f/0x7c0 net/core/net_namespace.c:579
 create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:132
 unshare_nsproxy_namespaces+0xf2/0x220 kernel/nsproxy.c:234
 ksys_unshare+0x438/0xab0 kernel/fork.c:3269
 __do_sys_unshare kernel/fork.c:3343 [inline]
 __se_sys_unshare kernel/fork.c:3341 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3341
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880584fb800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 976 bytes to the right of
 allocated 640-byte region [ffff8880584fb800, ffff8880584fba80)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880584fa800 pfn:0x584f8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88801bc42dc0 ffffea0001620610 ffffea0000eade10
raw: ffff8880584fa800 000000080010000b 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801bc42dc0 ffffea0001620610 ffffea0000eade10
head: ffff8880584fa800 000000080010000b 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 13, tgid 13 (kworker/u32:1), ts 56489698437, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304
 alloc_slab_page mm/slub.c:3266 [inline]
 allocate_slab mm/slub.c:3380 [inline]
 new_slab+0xa2/0x640 mm/slub.c:3426
 refill_objects+0xe3/0x410 mm/slub.c:7310
 refill_sheaf mm/slub.c:2804 [inline]
 __pcs_replace_empty_main+0x376/0x680 mm/slub.c:4675
 alloc_from_pcs mm/slub.c:4773 [inline]
 slab_alloc_node mm/slub.c:4905 [inline]
 __do_kmalloc_node mm/slub.c:5333 [inline]
 __kmalloc_noprof+0x66d/0x820 mm/slub.c:5359
 _kmalloc_noprof include/linux/slab.h:992 [inline]
 _kzalloc_noprof include/linux/slab.h:1309 [inline]
 neigh_alloc net/core/neighbour.c:518 [inline]
 ___neigh_create+0x1532/0x2940 net/core/neighbour.c:652
 ip6_finish_output2+0xffa/0x1ce0 net/ipv6/ip6_output.c:128
 __ip6_finish_output+0x357/0xdf0 net/ipv6/ip6_output.c:208
 ip6_finish_output net/ipv6/ip6_output.c:219 [inline]
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip6_output+0x2aa/0xa60 net/ipv6/ip6_output.c:246
 dst_output include/net/dst.h:470 [inline]
 NF_HOOK include/linux/netfilter.h:318 [inline]
 ndisc_send_skb+0xa85/0x1bf0 net/ipv6/ndisc.c:512
 ndisc_send_ns+0xc6/0x140 net/ipv6/ndisc.c:671
 addrconf_dad_work+0xca1/0x1360 net/ipv6/addrconf.c:4317
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8880584fbd00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880584fbd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880584fbe00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                 ^
 ffff8880584fbe80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880584fbf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


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