attempt to access beyond end of device loop4: rw=0, want=6491538, limit=128 Buffer I/O error on dev loop4, logical block 3245768, async page read ================================================================== BUG: KASAN: use-after-free in sysv_new_inode+0x1062/0x11f0 fs/sysv/ialloc.c:153 Read of size 2 at addr ffff88806912d1ce by task syz.4.19/5054 CPU: 1 PID: 5054 Comm: syz.4.19 Not tainted 5.15.173-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 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_symlink+0x9b/0x180 fs/sysv/namei.c:80 vfs_symlink+0x247/0x3d0 fs/namei.c:4429 do_symlinkat+0x1fd/0x600 fs/namei.c:4458 __do_sys_symlink fs/namei.c:4480 [inline] __se_sys_symlink fs/namei.c:4478 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4478 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: 0033:0x7fa8c0e45ff9 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:00007fa8c00c6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 00007fa8c0ffdf80 RCX: 00007fa8c0e45ff9 RDX: 0000000000000000 RSI: 00000000200059c0 RDI: 00000000200049c0 RBP: 00007fa8c0eb8296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa8c0ffdf80 R15: 00007ffd922c42d8 The buggy address belongs to the page: page:ffffea0001a44b40 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x6912d flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001a44b88 ffffea0001a44b08 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 0x1100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 4800, ts 98831590556, free_ts 102079745776 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x3b78/0x3d40 mm/page_alloc.c:4192 __alloc_pages+0x272/0x700 mm/page_alloc.c:5464 alloc_pages_vma+0x39a/0x800 mm/mempolicy.c:2146 do_anonymous_page mm/memory.c:3836 [inline] handle_pte_fault mm/memory.c:4646 [inline] __handle_mm_fault mm/memory.c:4783 [inline] handle_mm_fault+0x2f49/0x5960 mm/memory.c:4881 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:606 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 unmap_region+0x304/0x350 mm/mmap.c:2668 __do_munmap+0x12db/0x1740 mm/mmap.c:2899 __vm_munmap+0x134/0x230 mm/mmap.c:2922 __do_sys_munmap mm/mmap.c:2948 [inline] __se_sys_munmap mm/mmap.c:2944 [inline] __x64_sys_munmap+0x67/0x70 mm/mmap.c:2944 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: ffff88806912d080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88806912d100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88806912d180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88806912d200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88806912d280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================