syzbot

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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:326 [inline]
BUG: KASAN: slab-use-after-free in move_to_new_folio+0x231/0x12e0 mm/migrate.c:970
Read of size 8 at addr ffff888020a43280 by task kcompactd0/33

CPU: 0 UID: 0 PID: 33 Comm: kcompactd0 Not tainted 6.11.0-rc4-syzkaller-00255-gd2bafcf224f3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 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:326 [inline]
 move_to_new_folio+0x231/0x12e0 mm/migrate.c:970
 migrate_folio_move mm/migrate.c:1288 [inline]
 migrate_pages_batch+0x2527/0x3560 mm/migrate.c:1818
 migrate_pages_sync mm/migrate.c:1884 [inline]
 migrate_pages+0x1f59/0x3460 mm/migrate.c:1993
 compact_zone+0x3404/0x4af0 mm/compaction.c:2671
 compact_node+0x2de/0x460 mm/compaction.c:2935
 kcompactd+0x788/0x1530 mm/compaction.c:3233
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 27:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3988 [inline]
 slab_alloc_node mm/slub.c:4037 [inline]
 kmem_cache_alloc_lru_noprof+0x139/0x2b0 mm/slub.c:4056
 shmem_alloc_inode+0x28/0x40 mm/shmem.c:4622
 alloc_inode fs/inode.c:263 [inline]
 new_inode_pseudo fs/inode.c:1073 [inline]
 new_inode+0x6e/0x310 fs/inode.c:1092
 __shmem_get_inode mm/shmem.c:2658 [inline]
 shmem_get_inode+0x34a/0xd50 mm/shmem.c:2729
 shmem_mknod+0x5f/0x1e0 mm/shmem.c:3426
 vfs_mknod+0x36d/0x3b0 fs/namei.c:4088
 handle_create drivers/base/devtmpfs.c:219 [inline]
 handle drivers/base/devtmpfs.c:384 [inline]
 devtmpfs_work_loop+0x963/0x1040 drivers/base/devtmpfs.c:399
 devtmpfsd+0x4c/0x50 drivers/base/devtmpfs.c:441
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 26500:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2252 [inline]
 slab_free mm/slub.c:4473 [inline]
 kmem_cache_free+0x145/0x350 mm/slub.c:4548
 rcu_do_batch kernel/rcu/tree.c:2569 [inline]
 rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2843
 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
 do_softirq+0x11b/0x1e0 kernel/softirq.c:455
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 srcu_invoke_callbacks+0x246/0x490 kernel/rcu/srcutree.c:1759
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd10 kernel/workqueue.c:3389
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541
 __call_rcu_common kernel/rcu/tree.c:3106 [inline]
 call_rcu+0x167/0xa70 kernel/rcu/tree.c:3210
 destroy_inode fs/inode.c:318 [inline]
 evict+0x88b/0x950 fs/inode.c:729
 do_unlinkat+0x512/0x830 fs/namei.c:4493
 __do_sys_unlink fs/namei.c:4534 [inline]
 __se_sys_unlink fs/namei.c:4532 [inline]
 __x64_sys_unlink+0x47/0x50 fs/namei.c:4532
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888020a42db8
 which belongs to the cache shmem_inode_cache of size 1544
The buggy address is located 1224 bytes inside of
 freed 1544-byte region [ffff888020a42db8, ffff888020a433c0)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x20a40
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xfdffffff(slab)
raw: 00fff00000000040 ffff8880172e7140 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000130013 00000001fdffffff 0000000000000000
head: 00fff00000000040 ffff8880172e7140 dead000000000122 0000000000000000
head: 0000000000000000 0000000000130013 00000001fdffffff 0000000000000000
head: 00fff00000000003 ffffea0000829001 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 27, tgid 27 (kdevtmpfs), ts 6968109734, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493
 prep_new_page mm/page_alloc.c:1501 [inline]
 get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3439
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4695
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x5f/0x120 mm/slub.c:2321
 allocate_slab+0x5a/0x2f0 mm/slub.c:2484
 new_slab mm/slub.c:2537 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3723
 __slab_alloc+0x58/0xa0 mm/slub.c:3813
 __slab_alloc_node mm/slub.c:3866 [inline]
 slab_alloc_node mm/slub.c:4025 [inline]
 kmem_cache_alloc_lru_noprof+0x1c5/0x2b0 mm/slub.c:4056
 shmem_alloc_inode+0x28/0x40 mm/shmem.c:4622
 alloc_inode fs/inode.c:263 [inline]
 new_inode_pseudo fs/inode.c:1073 [inline]
 new_inode+0x6e/0x310 fs/inode.c:1092
 __shmem_get_inode mm/shmem.c:2658 [inline]
 shmem_get_inode+0x34a/0xd50 mm/shmem.c:2729
 shmem_mknod+0x5f/0x1e0 mm/shmem.c:3426
 vfs_mknod+0x36d/0x3b0 fs/namei.c:4088
 handle_create drivers/base/devtmpfs.c:219 [inline]
 handle drivers/base/devtmpfs.c:384 [inline]
 devtmpfs_work_loop+0x963/0x1040 drivers/base/devtmpfs.c:399
 devtmpfsd+0x4c/0x50 drivers/base/devtmpfs.c:441
 kthread+0x2f0/0x390 kernel/kthread.c:389
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888020a43180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888020a43200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888020a43280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888020a43300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888020a43380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
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