loop0: detected capacity change from 0 to 128 VFS: Found a Xenix FS (block size = 1024) on device loop0 syz-executor168: attempt to access beyond end of device loop0: rw=0, sector=6491536, nr_sectors = 2 limit=128 Buffer I/O error on dev loop0, logical block 3245768, async page read ================================================================== BUG: KASAN: use-after-free in sysv_new_inode+0xfc7/0x1160 fs/sysv/ialloc.c:153 Read of size 2 at addr ffff8880728381ce by task syz-executor168/5824 CPU: 0 UID: 0 PID: 5824 Comm: syz-executor168 Not tainted 6.13.0-rc3-syzkaller-00289-g48f506ad0b68 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __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:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 sysv_new_inode+0xfc7/0x1160 fs/sysv/ialloc.c:153 sysv_mknod+0x4e/0xe0 fs/sysv/namei.c:53 lookup_open fs/namei.c:3649 [inline] open_last_lookups fs/namei.c:3748 [inline] path_openat+0x1c03/0x3590 fs/namei.c:3984 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_openat fs/open.c:1433 [inline] __se_sys_openat fs/open.c:1428 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1428 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: 0033:0x7f6e9a7c00e9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff3eea2748 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6e9a7c00e9 RDX: 000000000000275a RSI: 00000000200000c0 RDI: 00000000ffffff9c RBP: 00000000ffffffff R08: 0000000000009e87 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff3eea2790 R13: 00007fff3eea27d0 R14: 0000000000010000 R15: 0000000000000003 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x555c0abbc pfn:0x72838 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001ca0e48 ffffea0001d5cb48 0000000000000000 raw: 0000000555c0abbc 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 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO), pid 5815, tgid 5815 (sftp-server), ts 73422263585, free_ts 73512947408 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1558 prep_new_page mm/page_alloc.c:1566 [inline] get_page_from_freelist+0x3651/0x37a0 mm/page_alloc.c:3476 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4753 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2269 folio_alloc_mpol_noprof mm/mempolicy.c:2287 [inline] vma_alloc_folio_noprof+0x12e/0x230 mm/mempolicy.c:2317 folio_prealloc+0x2e/0x170 alloc_anon_folio mm/memory.c:4752 [inline] do_anonymous_page mm/memory.c:4809 [inline] do_pte_missing mm/memory.c:3977 [inline] handle_pte_fault+0x2c98/0x5ed0 mm/memory.c:5801 __handle_mm_fault mm/memory.c:5944 [inline] handle_mm_fault+0x1053/0x1ad0 mm/memory.c:6112 do_user_addr_fault arch/x86/mm/fault.c:1338 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x459/0x8b0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 page last free pid 5815 tgid 5815 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_folios+0xe23/0x1890 mm/page_alloc.c:2706 folios_put_refs+0x76c/0x860 mm/swap.c:962 free_pages_and_swap_cache+0x2ea/0x690 mm/swap_state.c:332 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:366 [inline] tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:373 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465 exit_mmap+0x496/0xc20 mm/mmap.c:1681 __mmput+0x115/0x3b0 kernel/fork.c:1348 exit_mm+0x220/0x310 kernel/exit.c:570 do_exit+0x9ad/0x28e0 kernel/exit.c:925 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232 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 Memory state around the buggy address: ffff888072838080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888072838100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888072838180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888072838200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888072838280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================