================================================================== BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x700/0x880 fs/ext4/dir.c:85 Read of size 2 at addr ffff888128021003 by task syz-executor.0/352 CPU: 1 PID: 352 Comm: syz-executor.0 Not tainted 6.1.75-syzkaller-1151070-g68c821783c76 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x158/0x4e0 mm/kasan/report.c:427 kasan_report+0x13c/0x170 mm/kasan/report.c:531 __asan_report_load2_noabort+0x14/0x20 mm/kasan/report_generic.c:349 __ext4_check_dir_entry+0x700/0x880 fs/ext4/dir.c:85 ext4_readdir+0x1386/0x3930 fs/ext4/dir.c:258 iterate_dir+0x265/0x610 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64+0x1c1/0x460 fs/readdir.c:354 __x64_sys_getdents64+0x7b/0x90 fs/readdir.c:354 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f96f8e7dd69 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f96f9b4c0c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00007f96f8fabf80 RCX: 00007f96f8e7dd69 RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f96f8eca49e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f96f8fabf80 R15: 00007ffd591c1848 The buggy address belongs to the physical page: page:ffffea0004a00840 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x128021 flags: 0x4000000000000000(zone=1) raw: 4000000000000000 ffffea0004a00b48 ffffea0004a005c8 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 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 342, tgid 342 (mkswap), ts 39214023169, free_ts 39224308353 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x213/0x220 mm/page_alloc.c:2590 prep_new_page+0x1b/0x110 mm/page_alloc.c:2597 get_page_from_freelist+0x27ea/0x2870 mm/page_alloc.c:4425 __alloc_pages+0x3a1/0x780 mm/page_alloc.c:5712 __folio_alloc+0x15/0x40 mm/page_alloc.c:5744 __folio_alloc_node include/linux/gfp.h:245 [inline] folio_alloc include/linux/gfp.h:274 [inline] alloc_page_vma include/linux/gfp.h:283 [inline] wp_page_copy+0x261/0x1690 mm/memory.c:3181 do_wp_page+0xc25/0xdf0 handle_pte_fault mm/memory.c:5119 [inline] __handle_mm_fault mm/memory.c:5243 [inline] handle_mm_fault+0x15a2/0x2f40 mm/memory.c:5383 do_user_addr_fault arch/x86/mm/fault.c:1363 [inline] handle_page_fault arch/x86/mm/fault.c:1506 [inline] exc_page_fault+0x3b3/0x700 arch/x86/mm/fault.c:1562 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:570 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1498 [inline] free_pcp_prepare mm/page_alloc.c:1572 [inline] free_unref_page_prepare+0x83d/0x850 mm/page_alloc.c:3498 free_unref_page_list+0xf1/0x7b0 mm/page_alloc.c:3646 release_pages+0xf7f/0xfe0 mm/swap.c:1063 free_pages_and_swap_cache+0x8a/0xa0 mm/swap_state.c:314 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:254 [inline] tlb_flush_mmu mm/mmu_gather.c:261 [inline] tlb_finish_mmu+0x1e0/0x3f0 mm/mmu_gather.c:361 exit_mmap+0x421/0x940 mm/mmap.c:3348 __mmput+0x95/0x310 kernel/fork.c:1298 mmput+0x56/0x170 kernel/fork.c:1321 exit_mm kernel/exit.c:566 [inline] do_exit+0xb29/0x2b80 kernel/exit.c:862 do_group_exit+0x21a/0x2d0 kernel/exit.c:1025 __do_sys_exit_group kernel/exit.c:1036 [inline] __se_sys_exit_group kernel/exit.c:1034 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1034 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff888128020f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888128020f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888128021000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888128021080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888128021100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== EXT4-fs error (device loop0): ext4_readdir:260: inode #2: block 255: comm syz-executor.0: path /root/syzkaller-testdir2978060809/syzkaller.0Ph3Va/0/file0: bad entry in directory: directory entry overrun - offset=1023, inode=2062502400, rec_len=6308, size=1024 fake=0