loop1: detected capacity change from 0 to 32768 ocfs2: Slot 0 on device (7,1) was already allocated to this node! ocfs2: Mounting device (7,1) on (node local, slot 0) with ordered data mode. (syz.1.249,7828,1):ocfs2_check_dir_entry:[ 240.288180][ T7828] (syz.1.249,7828,1):ocfs2_check_dir_entry:325 ERROR: bad entry in directory #65: directory entry overrun - offset=0, inode=281474976710721, rec_len=32768, name_len=1 ================================================================== BUG: KASAN: use-after-free in ocfs2_check_dir_entry fs/ocfs2/dir.c:305 [inline] BUG: KASAN: use-after-free in ocfs2_dir_foreach_blk_id fs/ocfs2/dir.c:1805 [inline] BUG: KASAN: use-after-free in ocfs2_dir_foreach_blk+0x1501/0x18a0 fs/ocfs2/dir.c:1933 Read of size 2 at addr ffff88803febc2d0 by task syz.1.249/7828 CPU: 1 UID: 0 PID: 7828 Comm: syz.1.249 Not tainted syzkaller #0 PREEMPT_{RT,(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_check_dir_entry fs/ocfs2/dir.c:305 [inline] ocfs2_dir_foreach_blk_id fs/ocfs2/dir.c:1805 [inline] ocfs2_dir_foreach_blk+0x1501/0x18a0 fs/ocfs2/dir.c:1933 ocfs2_readdir+0x260/0x4d0 fs/ocfs2/dir.c:1977 wrap_directory_iterator+0x96/0xe0 fs/readdir.c:65 iterate_dir+0x3a2/0x580 fs/readdir.c:108 __do_sys_getdents fs/readdir.c:326 [inline] __se_sys_getdents+0xe4/0x250 fs/readdir.c:312 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: 0033:0x7fabfb68eec9 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:00007fabf98ee038 EFLAGS: 00000246 ORIG_RAX: 000000000000004e RAX: ffffffffffffffda RBX: 00007fabfb8e5fa0 RCX: 00007fabfb68eec9 RDX: 0000000000000054 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007fabfb711f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fabfb8e6038 R14: 00007fabfb8e5fa0 R15: 00007ffdb10d9098 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x53a pfn:0x3febc flags: 0x80000000000000(node=0|zone=1) raw: 0080000000000000 dead000000000100 dead000000000122 0000000000000000 raw: 000000000000053a 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 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 7813, tgid 7812 (syz.2.247), ts 238217162110, free_ts 238512851512 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416 folio_alloc_mpol_noprof+0x39/0xe0 mm/mempolicy.c:2435 shmem_alloc_folio mm/shmem.c:1871 [inline] shmem_alloc_and_add_folio mm/shmem.c:1910 [inline] shmem_get_folio_gfp+0x633/0x1a70 mm/shmem.c:2533 shmem_get_folio mm/shmem.c:2639 [inline] shmem_write_begin+0xef/0x2a0 mm/shmem.c:3289 generic_perform_write+0x29a/0x8c0 mm/filemap.c:4242 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3464 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5d2/0xb40 fs/read_write.c:686 ksys_write+0x14b/0x260 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 7813 tgid 7812 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] free_unref_folios+0xc22/0x1860 mm/page_alloc.c:2963 folios_put_refs+0x569/0x670 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1120 shmem_truncate_range mm/shmem.c:1232 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1360 evict+0x501/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 __fput+0x69d/0xa80 fs/file_table.c:476 fput_close_sync+0x119/0x200 fs/file_table.c:573 __do_sys_close fs/open.c:1589 [inline] __se_sys_close fs/open.c:1574 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1574 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 Memory state around the buggy address: ffff88803febc180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88803febc200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88803febc280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88803febc300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88803febc380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================