loop1: detected capacity change from 0 to 128 VFS: Found a Xenix FS (block size = 1024) on device loop1 ================================================================== BUG: KASAN: use-after-free in sysv_new_inode+0x107e/0x1210 fs/sysv/ialloc.c:153 Read of size 2 at addr ffff88804f7191ce by task syz.1.430/5679 CPU: 1 PID: 5679 Comm: syz.1.430 Not tainted 6.1.127-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:427 kasan_report+0x136/0x160 mm/kasan/report.c:531 sysv_new_inode+0x107e/0x1210 fs/sysv/ialloc.c:153 sysv_mkdir+0x3a/0x120 fs/sysv/namei.c:121 vfs_mkdir+0x3b6/0x590 fs/namei.c:4106 do_mkdirat+0x225/0x360 fs/namei.c:4131 __do_sys_mkdir fs/namei.c:4151 [inline] __se_sys_mkdir fs/namei.c:4149 [inline] __x64_sys_mkdir+0x6a/0x80 fs/namei.c:4149 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f068e38cd29 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:00007f068f1c6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007f068e5a5fa0 RCX: 00007f068e38cd29 RDX: 0000000000000000 RSI: 0000000000000040 RDI: 0000000020000100 RBP: 00007f068e40e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f068e5a5fa0 R15: 00007ffc03af03f8 The buggy address belongs to the physical page: page:ffffea00013dc640 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x4f719 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001469348 ffffea00013dc688 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 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO), pid 5631, tgid 5631 (syz.2.418), ts 212497193992, free_ts 215850004701 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x3731/0x38d0 mm/page_alloc.c:4328 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5605 __folio_alloc+0xf/0x30 mm/page_alloc.c:5637 vma_alloc_folio+0x486/0x990 mm/mempolicy.c:2243 alloc_page_vma include/linux/gfp.h:284 [inline] do_anonymous_page mm/memory.c:4189 [inline] handle_pte_fault mm/memory.c:5027 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x2e8e/0x5340 mm/memory.c:5292 do_user_addr_fault arch/x86/mm/fault.c:1340 [inline] handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x26f/0x620 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x12a6/0x15b0 mm/page_alloc.c:3384 free_unref_page_list+0x663/0x900 mm/page_alloc.c:3525 release_pages+0x24c4/0x27a0 mm/swap.c:1035 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:254 [inline] tlb_flush_mmu+0xfc/0x210 mm/mmu_gather.c:261 tlb_finish_mmu+0xce/0x1f0 mm/mmu_gather.c:361 exit_mmap+0x3b3/0x980 mm/mmap.c:3250 __mmput+0x115/0x3c0 kernel/fork.c:1200 exit_mm+0x226/0x300 kernel/exit.c:565 do_exit+0x9f1/0x26a0 kernel/exit.c:858 do_group_exit+0x202/0x2b0 kernel/exit.c:1021 get_signal+0x16f7/0x17d0 kernel/signal.c:2871 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 Memory state around the buggy address: ffff88804f719080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88804f719100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88804f719180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88804f719200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88804f719280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================