================================================================== BUG: KASAN: use-after-free in sysv_new_inode+0x107e/0x1210 fs/sysv/ialloc.c:153 Read of size 2 at addr ffff88805a75d1ce by task syz.0.82/3836 CPU: 0 PID: 3836 Comm: syz.0.82 Not tainted 6.1.97-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+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:395 kasan_report+0x136/0x160 mm/kasan/report.c:495 sysv_new_inode+0x107e/0x1210 fs/sysv/ialloc.c:153 sysv_mknod+0x4a/0xe0 fs/sysv/namei.c:53 lookup_open fs/namei.c:3484 [inline] open_last_lookups fs/namei.c:3552 [inline] path_openat+0x12f1/0x2e60 fs/namei.c:3782 do_filp_open+0x230/0x480 fs/namei.c:3812 do_sys_openat2+0x13b/0x500 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1345 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: 0033:0x7ff4f2375bd9 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:00007ff4f31d2048 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ff4f2504110 RCX: 00007ff4f2375bd9 RDX: 00000000000026e1 RSI: 00000000200000c0 RDI: ffffffffffffff9c RBP: 00007ff4f23e4e60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007ff4f2504110 R15: 00007ffe6154bdd8 The buggy address belongs to the physical page: page:ffffea000169d740 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x5a75d flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 dead000000000100 dead000000000122 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 3564, tgid 3564 (syz-executor), ts 63900583751, free_ts 91061122862 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2517 prep_new_page mm/page_alloc.c:2524 [inline] get_page_from_freelist+0x322e/0x33b0 mm/page_alloc.c:4283 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5551 __folio_alloc+0xf/0x30 mm/page_alloc.c:5583 vma_alloc_folio+0x486/0x990 mm/mempolicy.c:2243 alloc_page_vma include/linux/gfp.h:284 [inline] wp_page_copy+0x291/0x18c0 mm/memory.c:3134 handle_pte_fault mm/memory.c:5031 [inline] __handle_mm_fault mm/memory.c:5155 [inline] handle_mm_fault+0x2525/0x5340 mm/memory.c:5276 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:570 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1444 [inline] free_pcp_prepare mm/page_alloc.c:1494 [inline] free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3362 free_unref_page_list+0x663/0x900 mm/page_alloc.c:3503 release_pages+0x2836/0x2b40 mm/swap.c:1055 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+0x3c3/0x9f0 mm/mmap.c:3239 __mmput+0x115/0x3c0 kernel/fork.c:1199 exit_mm+0x226/0x300 kernel/exit.c:563 do_exit+0x9f6/0x26a0 kernel/exit.c:856 do_group_exit+0x202/0x2b0 kernel/exit.c:1019 get_signal+0x16f7/0x17d0 kernel/signal.c:2862 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: ffff88805a75d080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805a75d100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88805a75d180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88805a75d200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805a75d280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================