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BUG: KASAN: use-after-free in init_inode fs/reiserfs/inode.c:1314 [inline]
BUG: KASAN: use-after-free in reiserfs_read_locked_inode+0x20db/0x29b0 fs/reiserfs/inode.c:1560
Read of size 4 at addr ffff88805a360000 by task syz.1.36/5454

CPU: 0 UID: 0 PID: 5454 Comm: syz.1.36 Not tainted 6.12.0-rc1-syzkaller-00330-gfc20a3e57247 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 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
 init_inode fs/reiserfs/inode.c:1314 [inline]
 reiserfs_read_locked_inode+0x20db/0x29b0 fs/reiserfs/inode.c:1560
 reiserfs_fill_super+0x1361/0x2640 fs/reiserfs/super.c:2070
 mount_bdev+0x20c/0x2d0 fs/super.c:1679
 legacy_get_tree+0xf0/0x190 fs/fs_context.c:662
 vfs_get_tree+0x92/0x2b0 fs/super.c:1800
 do_new_mount+0x2be/0xb40 fs/namespace.c:3507
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4055 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032
 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
RIP: 0033:0x7f40dd17f79a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f40ddfefe68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f40ddfefef0 RCX: 00007f40dd17f79a
RDX: 0000000020001100 RSI: 0000000020001140 RDI: 00007f40ddfefeb0
RBP: 0000000020001100 R08: 00007f40ddfefef0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020001140
R13: 00007f40ddfefeb0 R14: 00000000000010e8 R15: 0000000020001180
 </TASK>

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:ffff88806aa63e68 index:0xb26 pfn:0x5a360
memcg:ffff88801c3f0000
aops:shmem_aops ino:40b dentry name(?):"memfd:syzkaller"
flags: 0xfff6000002003c(referenced|uptodate|dirty|lru|swapbacked|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff6000002003c ffffea00016e8bc8 ffffea000168d848 ffff88806aa63e68
raw: 0000000000000b26 0000000000000000 00000001ffffffff ffff88801c3f0000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 5445, tgid 5444 (syz.2.38), ts 85086518325, free_ts 84306660067
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 folio_alloc_mpol_noprof+0x36/0x50 mm/mempolicy.c:2283
 shmem_alloc_folio mm/shmem.c:1774 [inline]
 shmem_alloc_and_add_folio+0x49b/0x13d0 mm/shmem.c:1813
 shmem_get_folio_gfp+0x5a9/0x20a0 mm/shmem.c:2335
 shmem_get_folio mm/shmem.c:2441 [inline]
 shmem_write_begin+0x17e/0x460 mm/shmem.c:3046
 generic_perform_write+0x346/0x6d0 mm/filemap.c:4054
 shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3221
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0xa6f/0xc90 fs/read_write.c:683
 ksys_write+0x183/0x2b0 fs/read_write.c:736
 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
page last free pid 5442 tgid 5437 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_folios+0xf12/0x18d0 mm/page_alloc.c:2686
 folios_put_refs+0x76c/0x860 mm/swap.c:1007
 folio_batch_release include/linux/pagevec.h:101 [inline]
 shmem_undo_range+0x64c/0x1cf0 mm/shmem.c:1032
 shmem_truncate_range mm/shmem.c:1144 [inline]
 shmem_evict_inode+0x29b/0xa80 mm/shmem.c:1272
 evict+0x4ea/0x9b0 fs/inode.c:723
 __dentry_kill+0x20d/0x630 fs/dcache.c:615
 dput+0x19f/0x2b0 fs/dcache.c:857
 __fput+0x5d2/0x880 fs/file_table.c:439
 task_work_run+0x251/0x310 kernel/task_work.c:228
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa2f/0x28e0 kernel/exit.c:939
 do_group_exit+0x207/0x2c0 kernel/exit.c:1088
 get_signal+0x16a3/0x1740 kernel/signal.c:2917
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88805a35ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805a35ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805a360000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                   ^
 ffff88805a360080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805a360100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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