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:335 [inline]
BUG: KASAN: slab-use-after-free in move_to_new_folio+0x12e/0x700 mm/migrate.c:1040
Read of size 8 at addr ffff888025a5f3d0 by task syz.0.5453/18153

CPU: 1 UID: 0 PID: 18153 Comm: syz.0.5453 Not tainted 6.14.0-syzkaller-03576-g1e1ba8d23dae #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0xef/0x1a0 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:335 [inline]
 move_to_new_folio+0x12e/0x700 mm/migrate.c:1040
 migrate_folio_move mm/migrate.c:1358 [inline]
 migrate_folios_move mm/migrate.c:1710 [inline]
 migrate_pages_batch+0x201d/0x31a0 mm/migrate.c:1957
 migrate_pages_sync+0x12d/0x8a0 mm/migrate.c:1987
 migrate_pages+0x1b28/0x2350 mm/migrate.c:2096
 compact_zone+0x1f6d/0x4220 mm/compaction.c:2663
 compact_node+0x1a4/0x2d0 mm/compaction.c:2932
 compact_nodes mm/compaction.c:2954 [inline]
 sysctl_compaction_handler mm/compaction.c:3005 [inline]
 sysctl_compaction_handler+0x141/0x210 mm/compaction.c:2992
 proc_sys_call_handler+0x3d0/0x5b0 fs/proc/proc_sysctl.c:601
 iter_file_splice_write+0x91c/0x1150 fs/splice.c:738
 do_splice_from fs/splice.c:935 [inline]
 direct_splice_actor+0x18f/0x6c0 fs/splice.c:1158
 splice_direct_to_actor+0x342/0xa30 fs/splice.c:1102
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0x174/0x240 fs/splice.c:1227
 do_sendfile+0xafd/0xe50 fs/read_write.c:1368
 __do_sys_sendfile64 fs/read_write.c:1423 [inline]
 __se_sys_sendfile64 fs/read_write.c:1415 [inline]
 __x64_sys_sendfile64+0x154/0x220 fs/read_write.c:1415
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb94ff8d169
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:00007fb94ddf6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fb9501a5fa0 RCX: 00007fb94ff8d169
RDX: 00002000000000c0 RSI: 0000000000000003 RDI: 0000000000000004
RBP: 00007fb95000e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb9501a5fa0 R15: 00007ffecbed6148
 </TASK>

Allocated by task 18120:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4138 [inline]
 slab_alloc_node mm/slub.c:4187 [inline]
 kmem_cache_alloc_lru_noprof+0x1d0/0x3b0 mm/slub.c:4206
 shmem_alloc_inode+0x25/0x50 mm/shmem.c:5160
 alloc_inode+0x61/0x240 fs/inode.c:346
 new_inode+0x22/0x1c0 fs/inode.c:1145
 __shmem_get_inode mm/shmem.c:3058 [inline]
 shmem_get_inode+0x19a/0xfb0 mm/shmem.c:3132
 shmem_symlink+0xf7/0x780 mm/shmem.c:4107
 vfs_symlink fs/namei.c:4688 [inline]
 vfs_symlink+0x400/0x680 fs/namei.c:4672
 do_symlinkat+0x261/0x310 fs/namei.c:4714
 __do_sys_symlinkat fs/namei.c:4730 [inline]
 __se_sys_symlinkat fs/namei.c:4727 [inline]
 __x64_sys_symlinkat+0x93/0xc0 fs/namei.c:4727
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 23:
 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:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2376 [inline]
 slab_free mm/slub.c:4633 [inline]
 kmem_cache_free+0x2d4/0x4d0 mm/slub.c:4735
 i_callback+0x43/0x70 fs/inode.c:325
 rcu_do_batch kernel/rcu/tree.c:2568 [inline]
 rcu_core+0x799/0x14e0 kernel/rcu/tree.c:2824
 handle_softirqs+0x216/0x8e0 kernel/softirq.c:561
 run_ksoftirqd kernel/softirq.c:950 [inline]
 run_ksoftirqd+0x3a/0x60 kernel/softirq.c:942
 smpboot_thread_fn+0x678/0xa70 kernel/smpboot.c:164
 kthread+0x3a4/0x760 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Last potentially related work creation:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xb8/0xd0 mm/kasan/generic.c:548
 __call_rcu_common.constprop.0+0x9a/0x9f0 kernel/rcu/tree.c:3082
 destroy_inode+0x12c/0x1b0 fs/inode.c:401
 evict+0x5b4/0x920 fs/inode.c:834
 iput_final fs/inode.c:1898 [inline]
 iput fs/inode.c:1924 [inline]
 iput+0x521/0x880 fs/inode.c:1910
 do_unlinkat+0x518/0x6a0 fs/namei.c:4615
 __do_sys_unlink fs/namei.c:4654 [inline]
 __se_sys_unlink fs/namei.c:4652 [inline]
 __x64_sys_unlink+0xc5/0x110 fs/namei.c:4652
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888025a5ef08
 which belongs to the cache shmem_inode_cache of size 1544
The buggy address is located 1224 bytes inside of
 freed 1544-byte region [ffff888025a5ef08, ffff888025a5f510)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x25a58
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888028185b01
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88814040dc80 ffffea0000d6c000 dead000000000002
raw: 0000000000000000 0000000000130013 00000000f5000000 ffff888028185b01
head: 00fff00000000040 ffff88814040dc80 ffffea0000d6c000 dead000000000002
head: 0000000000000000 0000000000130013 00000000f5000000 ffff888028185b01
head: 00fff00000000003 ffffea0000969601 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 26, tgid 26 (kdevtmpfs), ts 6038811187, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0x10c4/0x34c0 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x223/0x24d0 mm/page_alloc.c:4740
 alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2446 [inline]
 allocate_slab mm/slub.c:2610 [inline]
 new_slab+0x23c/0x330 mm/slub.c:2663
 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3849
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3939
 __slab_alloc_node mm/slub.c:4014 [inline]
 slab_alloc_node mm/slub.c:4175 [inline]
 kmem_cache_alloc_lru_noprof+0xf4/0x3b0 mm/slub.c:4206
 shmem_alloc_inode+0x25/0x50 mm/shmem.c:5160
 alloc_inode+0x61/0x240 fs/inode.c:346
 new_inode+0x22/0x1c0 fs/inode.c:1145
 __shmem_get_inode mm/shmem.c:3058 [inline]
 shmem_get_inode+0x19a/0xfb0 mm/shmem.c:3132
 shmem_mknod+0x1a8/0x450 mm/shmem.c:3854
 vfs_mknod+0x5d7/0x8e0 fs/namei.c:4193
 handle_create drivers/base/devtmpfs.c:233 [inline]
 handle drivers/base/devtmpfs.c:393 [inline]
 devtmpfs_work_loop+0x1c8/0x8e0 drivers/base/devtmpfs.c:408
 devtmpfsd+0x4c/0x50 drivers/base/devtmpfs.c:450
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888025a5f280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888025a5f300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888025a5f380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff888025a5f400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888025a5f480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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