================================================================== BUG: KASAN: use-after-free in sysv_new_inode+0x1062/0x11f0 fs/sysv/ialloc.c:153 Read of size 2 at addr ffff88805cc56b14 by task syz.2.2687/12930 CPU: 1 PID: 12930 Comm: syz.2.2687 Not tainted 5.15.161-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 sysv_new_inode+0x1062/0x11f0 fs/sysv/ialloc.c:153 sysv_mknod+0x4a/0xe0 fs/sysv/namei.c:53 lookup_open fs/namei.c:3462 [inline] open_last_lookups fs/namei.c:3532 [inline] path_openat+0x130a/0x2f20 fs/namei.c:3739 do_filp_open+0x21c/0x460 fs/namei.c:3769 do_sys_openat2+0x13b/0x500 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_open fs/open.c:1277 [inline] __se_sys_open fs/open.c:1273 [inline] __x64_sys_open+0x221/0x270 fs/open.c:1273 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fda5e46af19 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:00007fda5ceeb048 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fda5e5f8f60 RCX: 00007fda5e46af19 RDX: 0000000000000000 RSI: 0000000000060840 RDI: 00000000209e1000 RBP: 00007fda5e4d9bcd R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fda5e5f8f60 R15: 00007fff7f67e648 The buggy address belongs to the page: page:ffffea0001731580 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x100 pfn:0x5cc56 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea00011e3408 ffffea000173fec8 0000000000000000 raw: 0000000000000100 0000000000000000 00000000ffffff7f 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 0x1100cca(GFP_HIGHUSER_MOVABLE), pid 20687, ts 1008723520198, free_ts 1008750518942 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159 __alloc_pages+0x272/0x700 mm/page_alloc.c:5423 alloc_pages_vma+0x39a/0x800 mm/mempolicy.c:2146 wp_page_copy+0x24e/0x2070 mm/memory.c:3026 handle_pte_fault mm/memory.c:4639 [inline] __handle_mm_fault mm/memory.c:4756 [inline] handle_mm_fault+0x2a3d/0x5950 mm/memory.c:4854 do_user_addr_fault arch/x86/mm/fault.c:1357 [inline] handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x271/0x700 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433 release_pages+0x1bb9/0x1f40 mm/swap.c:963 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:240 [inline] tlb_flush_mmu mm/mmu_gather.c:247 [inline] tlb_finish_mmu+0x177/0x320 mm/mmu_gather.c:338 exit_mmap+0x3cd/0x670 mm/mmap.c:3188 __mmput+0x112/0x3b0 kernel/fork.c:1126 exit_mm+0x688/0x7f0 kernel/exit.c:548 do_exit+0x626/0x2480 kernel/exit.c:859 do_group_exit+0x144/0x310 kernel/exit.c:994 __do_sys_exit_group kernel/exit.c:1005 [inline] __se_sys_exit_group kernel/exit.c:1003 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1003 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff88805cc56a00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805cc56a80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88805cc56b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88805cc56b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805cc56c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================