syzbot

loop0: detected capacity change from 0 to 32768
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
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BUG: KASAN: use-after-free in ocfs2_match fs/ocfs2/dir.c:334 [inline]
BUG: KASAN: use-after-free in ocfs2_search_dirblock+0x267/0x7f0 fs/ocfs2/dir.c:367
Read of size 1 at addr ffff888071b948cb by task syz.0.214/4937

CPU: 0 PID: 4937 Comm: syz.0.214 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 ocfs2_match fs/ocfs2/dir.c:334 [inline]
 ocfs2_search_dirblock+0x267/0x7f0 fs/ocfs2/dir.c:367
 ocfs2_find_entry_id fs/ocfs2/dir.c:414 [inline]
 ocfs2_find_entry+0x114b/0x26d0 fs/ocfs2/dir.c:1078
 ocfs2_find_files_on_disk+0xea/0x310 fs/ocfs2/dir.c:1982
 ocfs2_lookup_ino_from_name+0xad/0x1e0 fs/ocfs2/dir.c:2004
 ocfs2_lookup+0x27b/0x9f0 fs/ocfs2/namei.c:122
 lookup_one_qstr_excl+0x117/0x240 fs/namei.c:1563
 filename_create+0x293/0x530 fs/namei.c:3836
 do_mkdirat+0xb3/0x520 fs/namei.c:4080
 __do_sys_mkdirat fs/namei.c:4105 [inline]
 __se_sys_mkdirat fs/namei.c:4103 [inline]
 __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4103
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7faf273b1657
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 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:00007faf2521be68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007faf2521bef0 RCX: 00007faf273b1657
RDX: 00000000000001ff RSI: 0000400000000280 RDI: 00000000ffffff9c
RBP: 00004000000002c0 R08: 0000400000000080 R09: 0000000000000000
R10: 00004000000002c0 R11: 0000000000000246 R12: 0000400000000280
R13: 00007faf2521beb0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

The buggy address belongs to the page:
page:ffffea0001c6e500 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x71b94
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001c6e548 ffffea0001c6e4c8 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Movable, gfp_mask 0x1100cca(GFP_HIGHUSER_MOVABLE), pid 4905, ts 110811814658, free_ts 112653553973
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x3b78/0x3d40 mm/page_alloc.c:4192
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5465
 alloc_pages_vma+0x39a/0x800 mm/mempolicy.c:2146
 shmem_alloc_page mm/shmem.c:1586 [inline]
 shmem_alloc_and_acct_page+0x4d1/0xd10 mm/shmem.c:1611
 shmem_getpage_gfp+0x17b1/0x3190 mm/shmem.c:1906
 shmem_fault+0x1d7/0x700 mm/shmem.c:2118
 __do_fault+0x139/0x340 mm/memory.c:3926
 do_read_fault mm/memory.c:4262 [inline]
 do_fault mm/memory.c:4390 [inline]
 handle_pte_fault mm/memory.c:4648 [inline]
 __handle_mm_fault mm/memory.c:4783 [inline]
 handle_mm_fault+0x376f/0x5960 mm/memory.c:4881
 faultin_page mm/gup.c:976 [inline]
 __get_user_pages+0x4ed/0x11d0 mm/gup.c:1197
 populate_vma_page_range+0x215/0x2a0 mm/gup.c:1529
 __mm_populate+0x2a5/0x4a0 mm/gup.c:1638
 mm_populate include/linux/mm.h:2632 [inline]
 vm_mmap_pgoff+0x22b/0x2d0 mm/util.c:556
 ksys_mmap_pgoff+0x13e/0x780 mm/mmap.c:1623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433
 release_pages+0x1bb9/0x1f40 mm/swap.c:963
 __pagevec_release+0x80/0xf0 mm/swap.c:983
 pagevec_release include/linux/pagevec.h:81 [inline]
 shmem_undo_range+0x67a/0x1b50 mm/shmem.c:964
 shmem_truncate_range mm/shmem.c:1063 [inline]
 shmem_evict_inode+0x21b/0xa00 mm/shmem.c:1145
 evict+0x529/0x930 fs/inode.c:622
 __dentry_kill+0x436/0x650 fs/dcache.c:586
 dentry_kill+0xbb/0x290
 dput+0xd8/0x1a0 fs/dcache.c:893
 __fput+0x636/0x8e0 fs/file_table.c:288
 task_work_run+0x129/0x1a0 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x6a3/0x2480 kernel/exit.c:874
 do_group_exit+0x144/0x310 kernel/exit.c:996
 get_signal+0xc66/0x14e0 kernel/signal.c:2900
 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867

Memory state around the buggy address:
 ffff888071b94780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888071b94800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888071b94880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff888071b94900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888071b94980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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