[syzbot] [gfs2] KASAN: slab-use-after-free Read in move_to_new_folio (4)

[syzbot <syzbot+9f0d09a59e1e92ee7b43@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    d7b8f8e20813 Linux 6.16-rc5
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15daabd4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f6cfc97245100778
dashboard link: https://syzkaller.appspot.com/bug?extid=9f0d09a59e1e92ee7b43
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=156df28c580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-d7b8f8e2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/88e0e9607487/vmlinux-d7b8f8e2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c0e31868d902/bzImage-d7b8f8e2.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/c8cd0473f7ee/mount_7.gz
  fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=111d4a8c580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9f0d09a59e1e92ee7b43@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline]
BUG: KASAN: slab-use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
BUG: KASAN: slab-use-after-free in mapping_inaccessible include/linux/pagemap.h:336 [inline]
BUG: KASAN: slab-use-after-free in move_to_new_folio+0x182/0x7a0 mm/migrate.c:983
Read of size 8 at addr ffff8880429ac910 by task kcompactd1/30

CPU: 0 UID: 0 PID: 30 Comm: kcompactd1 Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xd2/0x2b0 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:189
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 mapping_inaccessible include/linux/pagemap.h:336 [inline]
 move_to_new_folio+0x182/0x7a0 mm/migrate.c:983
 migrate_folio_move mm/migrate.c:1301 [inline]
 migrate_folios_move mm/migrate.c:1653 [inline]
 migrate_pages_batch+0x1c34/0x2830 mm/migrate.c:1900
 migrate_pages_sync mm/migrate.c:1930 [inline]
 migrate_pages+0x1bcc/0x2930 mm/migrate.c:2039
 compact_zone+0x23f4/0x4ad0 mm/compaction.c:2683
 compact_node+0x1d2/0x280 mm/compaction.c:2952
 kcompactd+0xbc8/0x1290 mm/compaction.c:3250
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 5644:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4148 [inline]
 slab_alloc_node mm/slub.c:4197 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204
 gfs2_glock_get+0x263/0xec0 fs/gfs2/glock.c:1183
 gfs2_inode_lookup+0x215/0xb10 fs/gfs2/inode.c:135
 gfs2_dir_search+0x168/0x220 fs/gfs2/dir.c:1667
 gfs2_lookupi+0x3d9/0x5a0 fs/gfs2/inode.c:340
 gfs2_jindex_hold fs/gfs2/ops_fstype.c:574 [inline]
 init_journal+0x54a/0x2260 fs/gfs2/ops_fstype.c:716
 init_inodes+0xdb/0x320 fs/gfs2/ops_fstype.c:851
 gfs2_fill_super+0x1939/0x20e0 fs/gfs2/ops_fstype.c:1253
 get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1681
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1335
 vfs_get_tree+0x92/0x2b0 fs/super.c:1804
 do_new_mount+0x24a/0xa40 fs/namespace.c:3902
 do_mount fs/namespace.c:4239 [inline]
 __do_sys_mount fs/namespace.c:4450 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4427
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 15:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4643 [inline]
 kmem_cache_free+0x18f/0x400 mm/slub.c:4745
 rcu_do_batch kernel/rcu/tree.c:2576 [inline]
 rcu_core+0xca8/0x1710 kernel/rcu/tree.c:2832
 handle_softirqs+0x286/0x870 kernel/softirq.c:579
 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968
 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:164
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
 __call_rcu_common kernel/rcu/tree.c:3094 [inline]
 call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3214
 __gfs2_glock_free+0xb44/0xc90 fs/gfs2/glock.c:172
 gfs2_glock_free+0x3c/0xa0 fs/gfs2/glock.c:178
 gfs2_glock_put_eventually fs/gfs2/super.c:1185 [inline]
 gfs2_evict_inode+0xae7/0x1000 fs/gfs2/super.c:1460
 evict+0x501/0x9c0 fs/inode.c:810
 gfs2_jindex_free+0x39c/0x440 fs/gfs2/super.c:79
 init_journal+0x8f1/0x2260 fs/gfs2/ops_fstype.c:833
 init_inodes+0xdb/0x320 fs/gfs2/ops_fstype.c:851
 gfs2_fill_super+0x1939/0x20e0 fs/gfs2/ops_fstype.c:1253
 get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1681
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1335
 vfs_get_tree+0x92/0x2b0 fs/super.c:1804
 do_new_mount+0x24a/0xa40 fs/namespace.c:3902
 do_mount fs/namespace.c:4239 [inline]
 __do_sys_mount fs/namespace.c:4450 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4427
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Second to last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
 insert_work+0x3d/0x330 kernel/workqueue.c:2183
 __queue_work+0xcfc/0xfe0 kernel/workqueue.c:2341
 queue_delayed_work_on+0x18b/0x280 kernel/workqueue.c:2561
 queue_delayed_work include/linux/workqueue.h:677 [inline]
 gfs2_glock_queue_work fs/gfs2/glock.c:250 [inline]
 do_xmote+0xce0/0x1220 fs/gfs2/glock.c:839
 glock_work_func+0x2a8/0x580 fs/gfs2/glock.c:1096
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff8880429ac548
 which belongs to the cache gfs2_glock(aspace) of size 1224
The buggy address is located 968 bytes inside of
 freed 1224-byte region [ffff8880429ac548, ffff8880429aca10)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880429acfd8 pfn:0x429ac
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff8880327f2640 ffffea000110bf00 0000000000000002
raw: ffff8880429acfd8 00000000000c0008 00000000f5000000 0000000000000000
head: 04fff00000000040 ffff8880327f2640 ffffea000110bf00 0000000000000002
head: ffff8880429acfd8 00000000000c0008 00000000f5000000 0000000000000000
head: 04fff00000000002 ffffea00010a6b01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5547, tgid 5547 (syz.0.16), ts 128645082054, free_ts 128606732548
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
 alloc_slab_page mm/slub.c:2451 [inline]
 allocate_slab+0x8a/0x3b0 mm/slub.c:2619
 new_slab mm/slub.c:2673 [inline]
 ___slab_alloc+0xbfc/0x1480 mm/slub.c:3859
 __slab_alloc mm/slub.c:3949 [inline]
 __slab_alloc_node mm/slub.c:4024 [inline]
 slab_alloc_node mm/slub.c:4185 [inline]
 kmem_cache_alloc_noprof+0x283/0x3c0 mm/slub.c:4204
 gfs2_glock_get+0x263/0xec0 fs/gfs2/glock.c:1183
 gfs2_inode_lookup+0x215/0xb10 fs/gfs2/inode.c:135
 gfs2_lookup_root fs/gfs2/ops_fstype.c:425 [inline]
 init_sb+0xa30/0x12c0 fs/gfs2/ops_fstype.c:494
 gfs2_fill_super+0x1605/0x20e0 fs/gfs2/ops_fstype.c:1220
 get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1681
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1335
 vfs_get_tree+0x92/0x2b0 fs/super.c:1804
 do_new_mount+0x24a/0xa40 fs/namespace.c:3902
 do_mount fs/namespace.c:4239 [inline]
 __do_sys_mount fs/namespace.c:4450 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4427
page last free pid 5547 tgid 5547 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1248 [inline]
 __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706
 stack_depot_save_flags+0x445/0x900 lib/stackdepot.c:678
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_save_track+0x4f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4148 [inline]
 slab_alloc_node mm/slub.c:4197 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204
 __kernfs_new_node+0xd7/0x7e0 fs/kernfs/dir.c:637
 kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:713
 kernfs_create_dir_ns+0x44/0x130 fs/kernfs/dir.c:1083
 sysfs_create_dir_ns+0x123/0x280 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:73 [inline]
 kobject_add_internal+0x59f/0xb40 lib/kobject.c:240
 kobject_add_varg lib/kobject.c:374 [inline]
 kobject_init_and_add+0x125/0x190 lib/kobject.c:457
 gfs2_sys_fs_add+0x234/0x450 fs/gfs2/sys.c:737
 gfs2_fill_super+0x13d6/0x20e0 fs/gfs2/ops_fstype.c:1206
 get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1681
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1335
 vfs_get_tree+0x92/0x2b0 fs/super.c:1804

Memory state around the buggy address:
 ffff8880429ac800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880429ac880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880429ac900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff8880429ac980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880429aca00: fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
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