loop2: detected capacity change from 0 to 32768 ocfs2: Mounting device (7,2) on (node local, slot 0) with ordered data mode. ================================================================== BUG: KASAN: use-after-free in ocfs2_find_victim_chain fs/ocfs2/suballoc.c:1447 [inline] BUG: KASAN: use-after-free in ocfs2_claim_suballoc_bits+0x8b2/0x2450 fs/ocfs2/suballoc.c:1996 Read of size 4 at addr ffff88806e720000 by task syz.2.1262/10918 CPU: 1 UID: 0 PID: 10918 Comm: syz.2.1262 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 ocfs2_find_victim_chain fs/ocfs2/suballoc.c:1447 [inline] ocfs2_claim_suballoc_bits+0x8b2/0x2450 fs/ocfs2/suballoc.c:1996 ocfs2_claim_metadata+0x178/0x4c0 fs/ocfs2/suballoc.c:2082 ocfs2_dx_dir_attach_index+0x1c1/0xd90 fs/ocfs2/dir.c:2333 ocfs2_expand_inline_dir fs/ocfs2/dir.c:3025 [inline] ocfs2_extend_dir+0x3994/0x4870 fs/ocfs2/dir.c:3207 ocfs2_prepare_dir_for_insert+0x2fe8/0x5450 fs/ocfs2/dir.c:4312 ocfs2_symlink+0xaa4/0x23e0 fs/ocfs2/namei.c:1875 vfs_symlink+0x143/0x2f0 fs/namei.c:4730 do_symlinkat+0x1b1/0x3f0 fs/namei.c:4756 __do_sys_symlink fs/namei.c:4777 [inline] __se_sys_symlink fs/namei.c:4775 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4775 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 RIP: 0033:0x7fd4d918eec9 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:00007fd4d9fb5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 00007fd4d93e5fa0 RCX: 00007fd4d918eec9 RDX: 0000000000000000 RSI: 0000200000000cc0 RDI: 00002000000003c0 RBP: 00007fd4d9211f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd4d93e6038 R14: 00007fd4d93e5fa0 R15: 00007ffef3c0f898 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xb05 pfn:0x6e720 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f0(buddy) raw: 00fff00000000000 ffffea0000e80808 ffff88813fffbf18 0000000000000000 raw: 0000000000000b05 0000000000000005 00000000f0000000 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 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 10852, tgid 10851 (syz.7.1231), ts 640657900046, free_ts 645159622456 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2435 shmem_alloc_folio mm/shmem.c:1908 [inline] shmem_alloc_and_add_folio+0x447/0xf60 mm/shmem.c:1947 shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2597 shmem_get_folio mm/shmem.c:2703 [inline] shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3353 generic_perform_write+0x2c5/0x900 mm/filemap.c:4175 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3528 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 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 page last free pid 9894 tgid 9894 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] free_unref_folios+0xdbd/0x1520 mm/page_alloc.c:2952 folios_put_refs+0x559/0x640 mm/swap.c:999 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1157 shmem_truncate_range mm/shmem.c:1269 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1397 evict+0x504/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 __fput+0x68e/0xa70 fs/file_table.c:476 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88806e71ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88806e71ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88806e720000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88806e720080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88806e720100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================