==================================================================
BUG: KASAN: slab-use-after-free in __lock_acquire+0x2de0/0x3cb0 kernel/locking/lockdep.c:5007
Read of size 8 at addr ffff888025e8fc18 by task udevd/4837

CPU: 0 UID: 0 PID: 4837 Comm: udevd Not tainted 6.11.0-rc6-syzkaller-00308-gb31c44928842 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 __lock_acquire+0x2de0/0x3cb0 kernel/locking/lockdep.c:5007
 lock_acquire kernel/locking/lockdep.c:5759 [inline]
 lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
 p9_tag_remove net/9p/client.c:397 [inline]
 p9_req_put net/9p/client.c:405 [inline]
 p9_req_put+0xaf/0x250 net/9p/client.c:402
 req_done+0x1e7/0x2f0 net/9p/trans_virtio.c:147
 vring_interrupt drivers/virtio/virtio_ring.c:2595 [inline]
 vring_interrupt+0x31b/0x400 drivers/virtio/virtio_ring.c:2570
 __handle_irq_event_percpu+0x229/0x7c0 kernel/irq/handle.c:158
 handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
 handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:210
 handle_edge_irq+0x263/0xd10 kernel/irq/chip.c:831
 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
 handle_irq arch/x86/kernel/irq.c:247 [inline]
 call_irq_handler arch/x86/kernel/irq.c:259 [inline]
 __common_interrupt+0xdf/0x250 arch/x86/kernel/irq.c:285
 common_interrupt+0xab/0xd0 arch/x86/kernel/irq.c:278
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
RIP: 0010:lock_acquire+0x33/0x560 kernel/locking/lockdep.c:5727
Code: 00 00 fc ff df 41 57 4d 89 cf 41 56 49 89 fe 41 55 41 89 d5 41 54 45 89 c4 55 53 48 81 ec b0 00 00 00 48 8d 5c 24 10 89 34 24 <48> c1 eb 03 89 4c 24 04 48 c7 44 24 10 b3 8a b5 41 48 01 d8 48 c7
RSP: 0018:ffffc900249e7998 EFLAGS: 00000282
RAX: dffffc0000000000 RBX: ffffc900249e79a8 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801ceb01e0
RBP: 1ffff9200493cf51 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000000 R14: ffff88801ceb01e0 R15: 0000000000000000
 down_read+0x9a/0x330 kernel/locking/rwsem.c:1526
 kernfs_iop_permission+0xba/0x120 fs/kernfs/inode.c:287
 do_inode_permission fs/namei.c:468 [inline]
 inode_permission fs/namei.c:535 [inline]
 inode_permission+0x388/0x5f0 fs/namei.c:510
 may_lookup fs/namei.c:1746 [inline]
 link_path_walk.part.0.constprop.0+0x1d7/0xd40 fs/namei.c:2352
 link_path_walk fs/namei.c:2335 [inline]
 path_lookupat+0x93/0x770 fs/namei.c:2565
 filename_lookup+0x1e5/0x5b0 fs/namei.c:2595
 do_readlinkat+0xcf/0x390 fs/stat.c:537
 __do_sys_readlink fs/stat.c:574 [inline]
 __se_sys_readlink fs/stat.c:571 [inline]
 __x64_sys_readlink+0x78/0xc0 fs/stat.c:571
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4396f17d47
Code: 73 01 c3 48 8b 0d e1 90 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 59 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d b1 90 0d 00 f7 d8 64 89 01 48
RSP: 002b:00007ffd88cca908 EFLAGS: 00000246 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007ffd88cca918 RCX: 00007f4396f17d47
RDX: 0000000000000400 RSI: 00007ffd88cca918 RDI: 00007ffd88ccadf8
RBP: 0000000000000400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000812 R11: 0000000000000246 R12: 00007ffd88ccadf8
R13: 00007ffd88ccad68 R14: 000055cf28500910 R15: 0000000000000000
 </TASK>

Allocated by task 5922:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387
 kmalloc_noprof include/linux/slab.h:681 [inline]
 p9_client_create+0xcf/0x11b0 net/9p/client.c:983
 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410
 v9fs_mount+0xc6/0xa50 fs/9p/vfs_super.c:122
 legacy_get_tree+0x109/0x220 fs/fs_context.c:662
 vfs_get_tree+0x8f/0x380 fs/super.c:1800
 do_new_mount fs/namespace.c:3472 [inline]
 path_mount+0x6e1/0x1f10 fs/namespace.c:3799
 do_mount fs/namespace.c:3812 [inline]
 __do_sys_mount fs/namespace.c:4020 [inline]
 __se_sys_mount fs/namespace.c:3997 [inline]
 __ia32_sys_mount+0x292/0x310 fs/namespace.c:3997
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Freed by task 5922:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240
 __kasan_slab_free+0x32/0x50 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2256 [inline]
 slab_free mm/slub.c:4477 [inline]
 kfree+0x12a/0x3b0 mm/slub.c:4598
 p9_client_create+0x9ca/0x11b0 net/9p/client.c:1054
 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410
 v9fs_mount+0xc6/0xa50 fs/9p/vfs_super.c:122
 legacy_get_tree+0x109/0x220 fs/fs_context.c:662
 vfs_get_tree+0x8f/0x380 fs/super.c:1800
 do_new_mount fs/namespace.c:3472 [inline]
 path_mount+0x6e1/0x1f10 fs/namespace.c:3799
 do_mount fs/namespace.c:3812 [inline]
 __do_sys_mount fs/namespace.c:4020 [inline]
 __se_sys_mount fs/namespace.c:3997 [inline]
 __ia32_sys_mount+0x292/0x310 fs/namespace.c:3997
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

The buggy address belongs to the object at ffff888025e8fc00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff888025e8fc00, ffff888025e8fe00)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x25e8c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xfdffffff(slab)
raw: 00fff00000000040 ffff88801ac42c80 0000000000000000 dead000000000001
raw: 0000000000000000 0000000080100010 00000001fdffffff 0000000000000000
head: 00fff00000000040 ffff88801ac42c80 0000000000000000 dead000000000001
head: 0000000000000000 0000000080100010 00000001fdffffff 0000000000000000
head: 00fff00000000002 ffffea000097a301 ffffffffffffffff 0000000000000000
head: ffff888000000004 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 5709, tgid 5708 (syz.0.239), ts 66996514555, free_ts 66918595547
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1500
 prep_new_page mm/page_alloc.c:1508 [inline]
 get_page_from_freelist+0x1351/0x2e50 mm/page_alloc.c:3446
 __alloc_pages_slowpath mm/page_alloc.c:4235 [inline]
 __alloc_pages_noprof+0x6ad/0x2460 mm/page_alloc.c:4715
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x4e/0xf0 mm/slub.c:2325
 allocate_slab mm/slub.c:2488 [inline]
 new_slab+0x84/0x260 mm/slub.c:2541
 ___slab_alloc+0xdac/0x1870 mm/slub.c:3727
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3817
 __slab_alloc_node mm/slub.c:3870 [inline]
 slab_alloc_node mm/slub.c:4029 [inline]
 __do_kmalloc_node mm/slub.c:4161 [inline]
 __kmalloc_node_noprof+0x367/0x440 mm/slub.c:4168
 kmalloc_array_node_noprof include/linux/slab.h:788 [inline]
 alloc_slab_obj_exts+0x41/0xa0 mm/slub.c:1976
 __memcg_slab_post_alloc_hook+0x2bc/0x9c0 mm/memcontrol.c:3019
 memcg_slab_post_alloc_hook mm/slub.c:2164 [inline]
 slab_post_alloc_hook mm/slub.c:4002 [inline]
 slab_alloc_node mm/slub.c:4041 [inline]
 kmem_cache_alloc_noprof+0x2cd/0x2f0 mm/slub.c:4048
 anon_vma_chain_alloc mm/rmap.c:142 [inline]
 anon_vma_clone+0xe1/0x5e0 mm/rmap.c:288
 anon_vma_fork+0x7a/0x620 mm/rmap.c:351
 dup_mmap kernel/fork.c:712 [inline]
 dup_mm kernel/fork.c:1672 [inline]
 copy_mm+0x192b/0x2550 kernel/fork.c:1721
 copy_process+0x3ea8/0x6f50 kernel/fork.c:2374
 kernel_clone+0xfd/0x960 kernel/fork.c:2781
page last free pid 4837 tgid 4837 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1101 [inline]
 free_unref_page+0x64a/0xe40 mm/page_alloc.c:2619
 __put_partials+0x14c/0x170 mm/slub.c:3055
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3992 [inline]
 slab_alloc_node mm/slub.c:4041 [inline]
 kmem_cache_alloc_noprof+0x121/0x2f0 mm/slub.c:4048
 getname_flags.part.0+0x4c/0x550 fs/namei.c:139
 getname_flags+0x93/0xf0 include/linux/audit.h:322
 do_readlinkat+0xb5/0x390 fs/stat.c:536
 __do_sys_readlink fs/stat.c:574 [inline]
 __se_sys_readlink fs/stat.c:571 [inline]
 __x64_sys_readlink+0x78/0xc0 fs/stat.c:571
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888025e8fb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888025e8fb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888025e8fc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888025e8fc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888025e8fd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess), 4 bytes skipped:
   0:	df 41 57             	filds  0x57(%rcx)
   3:	4d 89 cf             	mov    %r9,%r15
   6:	41 56                	push   %r14
   8:	49 89 fe             	mov    %rdi,%r14
   b:	41 55                	push   %r13
   d:	41 89 d5             	mov    %edx,%r13d
  10:	41 54                	push   %r12
  12:	45 89 c4             	mov    %r8d,%r12d
  15:	55                   	push   %rbp
  16:	53                   	push   %rbx
  17:	48 81 ec b0 00 00 00 	sub    $0xb0,%rsp
  1e:	48 8d 5c 24 10       	lea    0x10(%rsp),%rbx
  23:	89 34 24             	mov    %esi,(%rsp)
* 26:	48 c1 eb 03          	shr    $0x3,%rbx <-- trapping instruction
  2a:	89 4c 24 04          	mov    %ecx,0x4(%rsp)
  2e:	48 c7 44 24 10 b3 8a 	movq   $0x41b58ab3,0x10(%rsp)
  35:	b5 41
  37:	48 01 d8             	add    %rbx,%rax
  3a:	48                   	rex.W
  3b:	c7                   	.byte 0xc7