syzbot

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline]
BUG: KASAN: slab-use-after-free in gfs2_qd_dealloc+0x81/0xe0 fs/gfs2/quota.c:112
Write of size 4 at addr ffff88806bfc8b18 by task syz.5.814/9371

CPU: 0 UID: 0 PID: 9371 Comm: syz.5.814 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline]
 gfs2_qd_dealloc+0x81/0xe0 fs/gfs2/quota.c:112
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0xcab/0x1770 kernel/rcu/tree.c:2861
 handle_softirqs+0x286/0x870 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline]
 sysvec_call_function_single+0xa3/0xc0 arch/x86/kernel/smp.c:266
 </IRQ>
 <TASK>
 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:704
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]
RIP: 0010:folio_mapcount include/linux/mm.h:1207 [inline]
RIP: 0010:folio_maybe_mapped_shared+0xa9/0x2a0 include/linux/mm.h:2203
Code: 31 ff e8 3a d7 9c ff 49 83 e7 40 0f 85 78 01 00 00 e8 4b d2 9c ff 4c 8d 7b 30 4c 89 ff be 04 00 00 00 e8 4a 96 02 00 4c 89 f8 <48> c1 e8 03 0f b6 04 28 84 c0 0f 85 7a 01 00 00 45 8b 3f 41 8d 6f
RSP: 0018:ffffc900040475f0 EFLAGS: 00000256
RAX: ffffea00014320f0 RBX: ffffea00014320c0 RCX: ffffffff82233196
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffea00014320f0
RBP: dffffc0000000000 R08: ffffea00014320f3 R09: 1ffffd400028641e
R10: dffffc0000000000 R11: fffff9400028641f R12: 1ffffd4000286418
R13: 1ffffd4000286419 R14: ffffea00014320c8 R15: ffffea00014320f0
 migrate_folio_add+0x34/0x300 mm/mempolicy.c:1184
 queue_folios_pte_range+0xb23/0x1690 mm/mempolicy.c:746
 walk_pmd_range mm/pagewalk.c:130 [inline]
 walk_pud_range mm/pagewalk.c:224 [inline]
 walk_p4d_range mm/pagewalk.c:262 [inline]
 walk_pgd_range+0xfe9/0x1d40 mm/pagewalk.c:303
 __walk_page_range+0x14c/0x710 mm/pagewalk.c:410
 walk_page_range_mm+0x454/0x660 mm/pagewalk.c:506
 queue_pages_range mm/mempolicy.c:921 [inline]
 migrate_to_node mm/mempolicy.c:1239 [inline]
 do_migrate_pages+0x563/0x800 mm/mempolicy.c:1343
 kernel_migrate_pages mm/mempolicy.c:1858 [inline]
 __do_sys_migrate_pages mm/mempolicy.c:1876 [inline]
 __se_sys_migrate_pages+0x544/0x650 mm/mempolicy.c:1872
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f93c678f6c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f93c76a9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000100
RAX: ffffffffffffffda RBX: 00007f93c69e6180 RCX: 00007f93c678f6c9
RDX: 0000200000000040 RSI: 0000000000000005 RDI: 0000000000000000
RBP: 00007f93c6811f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000080 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f93c69e6218 R14: 00007f93c69e6180 R15: 00007fffd3865e58
 </TASK>

Allocated by task 9356:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __kmalloc_cache_noprof+0x3d5/0x6f0 mm/slub.c:5771
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 init_sbd fs/gfs2/ops_fstype.c:78 [inline]
 gfs2_fill_super+0x11c/0x20d0 fs/gfs2/ops_fstype.c:1128
 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1337
 vfs_get_tree+0x92/0x2b0 fs/super.c:1751
 fc_mount fs/namespace.c:1208 [inline]
 do_new_mount_fc fs/namespace.c:3651 [inline]
 do_new_mount+0x302/0xa10 fs/namespace.c:3727
 do_mount fs/namespace.c:4050 [inline]
 __do_sys_mount fs/namespace.c:4238 [inline]
 __se_sys_mount+0x313/0x410 fs/namespace.c:4215
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 9356:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587
 kasan_save_free_info mm/kasan/kasan.h:406 [inline]
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2543 [inline]
 slab_free mm/slub.c:6638 [inline]
 kfree+0x19a/0x6d0 mm/slub.c:6845
 free_sbd fs/gfs2/ops_fstype.c:71 [inline]
 gfs2_fill_super+0x1527/0x20d0 fs/gfs2/ops_fstype.c:1321
 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1337
 vfs_get_tree+0x92/0x2b0 fs/super.c:1751
 fc_mount fs/namespace.c:1208 [inline]
 do_new_mount_fc fs/namespace.c:3651 [inline]
 do_new_mount+0x302/0xa10 fs/namespace.c:3727
 do_mount fs/namespace.c:4050 [inline]
 __do_sys_mount fs/namespace.c:4238 [inline]
 __se_sys_mount+0x313/0x410 fs/namespace.c:4215
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88806bfc8000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2840 bytes inside of
 freed 8192-byte region [ffff88806bfc8000, ffff88806bfca000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6bfc8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801a027280 ffffea0001a81200 dead000000000003
raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801a027280 ffffea0001a81200 dead000000000003
head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001aff201 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 8611, tgid 8605 (syz.0.611), ts 448059183751, free_ts 447814389861
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:3059 [inline]
 allocate_slab+0x96/0x350 mm/slub.c:3232
 new_slab mm/slub.c:3286 [inline]
 ___slab_alloc+0xf56/0x1990 mm/slub.c:4655
 __slab_alloc+0x65/0x100 mm/slub.c:4778
 __slab_alloc_node mm/slub.c:4854 [inline]
 slab_alloc_node mm/slub.c:5276 [inline]
 __kmalloc_cache_noprof+0x411/0x6f0 mm/slub.c:5766
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 tipc_mon_create+0xc2/0x490 net/tipc/monitor.c:657
 tipc_enable_bearer net/tipc/bearer.c:357 [inline]
 __tipc_nl_bearer_enable+0xe16/0x13f0 net/tipc/bearer.c:1047
 __tipc_nl_compat_doit net/tipc/netlink_compat.c:371 [inline]
 tipc_nl_compat_doit+0x3bc/0x5f0 net/tipc/netlink_compat.c:393
 tipc_nl_compat_handle net/tipc/netlink_compat.c:-1 [inline]
 tipc_nl_compat_recv+0x83c/0xbe0 net/tipc/netlink_compat.c:1321
 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
page last free pid 5986 tgid 5986 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906
 discard_slab mm/slub.c:3330 [inline]
 __put_partials+0x146/0x170 mm/slub.c:3876
 put_cpu_partial+0x1f2/0x2e0 mm/slub.c:3951
 __slab_free+0x2b9/0x390 mm/slub.c:5929
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4978 [inline]
 slab_alloc_node mm/slub.c:5288 [inline]
 kmem_cache_alloc_node_noprof+0x433/0x710 mm/slub.c:5340
 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:660
 netlink_sendmsg+0x5c6/0xb30 net/netlink/af_netlink.c:1871
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x505/0x830 net/socket.c:2630
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
 __sys_sendmsg net/socket.c:2716 [inline]
 __do_sys_sendmsg net/socket.c:2721 [inline]
 __se_sys_sendmsg net/socket.c:2719 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88806bfc8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88806bfc8a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88806bfc8b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88806bfc8b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88806bfc8c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	31 ff                	xor    %edi,%edi
   2:	e8 3a d7 9c ff       	call   0xff9cd741
   7:	49 83 e7 40          	and    $0x40,%r15
   b:	0f 85 78 01 00 00    	jne    0x189
  11:	e8 4b d2 9c ff       	call   0xff9cd261
  16:	4c 8d 7b 30          	lea    0x30(%rbx),%r15
  1a:	4c 89 ff             	mov    %r15,%rdi
  1d:	be 04 00 00 00       	mov    $0x4,%esi
  22:	e8 4a 96 02 00       	call   0x29671
  27:	4c 89 f8             	mov    %r15,%rax
* 2a:	48 c1 e8 03          	shr    $0x3,%rax <-- trapping instruction
  2e:	0f b6 04 28          	movzbl (%rax,%rbp,1),%eax
  32:	84 c0                	test   %al,%al
  34:	0f 85 7a 01 00 00    	jne    0x1b4
  3a:	45 8b 3f             	mov    (%r15),%r15d
  3d:	41                   	rex.B
  3e:	8d                   	.byte 0x8d
  3f:	6f                   	outsl  %ds:(%rsi),(%dx)