sysv_free_block: flc_count > flc_size sysv_free_block: flc_count > flc_size sysv_free_block: flc_count > flc_size sysv_free_block: flc_count > flc_size sysv_free_block: flc_count > flc_size sysv_free_block: flc_count > flc_size sysv_free_block: flc_count > flc_size sysv_free_block: flc_count > flc_size sysv_free_block: flc_count > flc_size sysv_free_block: flc_count > flc_size ================================================================== BUG: KASAN: use-after-free in sysv_new_block+0x78c/0x960 fs/sysv/balloc.c:113 Read of size 4 at addr ffff88806e71f0c8 by task syz-executor.0/6220 CPU: 0 PID: 6220 Comm: syz-executor.0 Not tainted 6.6.0-rc2-syzkaller-00309-g8018e02a8703 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0x163/0x540 mm/kasan/report.c:475 kasan_report+0x175/0x1b0 mm/kasan/report.c:588 sysv_new_block+0x78c/0x960 fs/sysv/balloc.c:113 alloc_branch fs/sysv/itree.c:134 [inline] get_block+0x314/0x1700 fs/sysv/itree.c:255 __block_write_begin_int+0x555/0x1a40 fs/buffer.c:2107 __block_write_begin fs/buffer.c:2157 [inline] block_write_begin+0x9b/0x1e0 fs/buffer.c:2216 sysv_write_begin+0x31/0x70 fs/sysv/itree.c:490 generic_perform_write+0x31b/0x630 mm/filemap.c:3942 generic_file_write_iter+0xaf/0x310 mm/filemap.c:4063 call_write_iter include/linux/fs.h:1956 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x782/0xaf0 fs/read_write.c:584 ksys_write+0x1a0/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fa371e7c8d9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa372c210c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fa371f9bf80 RCX: 00007fa371e7c8d9 RDX: 00000000fffffe45 RSI: 00000000200000c0 RDI: 0000000000000004 RBP: 00007fa371ed8b20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fa371f9bf80 R15: 00007ffd95f8b8a8 The buggy address belongs to the physical page: page:ffffea0001b9c7c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x6e71f flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() 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 5385, tgid 5385 (syz-executor.0), ts 99107810027, free_ts 99425367493 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1536 prep_new_page mm/page_alloc.c:1543 [inline] get_page_from_freelist+0x31db/0x3360 mm/page_alloc.c:3170 __alloc_pages+0x255/0x670 mm/page_alloc.c:4426 __folio_alloc+0x13/0x30 mm/page_alloc.c:4458 vma_alloc_folio+0x48a/0x9a0 mm/mempolicy.c:2259 wp_page_copy mm/memory.c:3074 [inline] do_wp_page+0x1456/0x4190 mm/memory.c:3449 handle_pte_fault mm/memory.c:4994 [inline] __handle_mm_fault mm/memory.c:5119 [inline] handle_mm_fault+0x1b45/0x62b0 mm/memory.c:5284 do_user_addr_fault arch/x86/mm/fault.c:1364 [inline] handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x455/0x860 arch/x86/mm/fault.c:1561 asm_exc_page_fault+0x26/0x30 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:1136 [inline] free_unref_page_prepare+0x8c3/0x9f0 mm/page_alloc.c:2312 free_unref_page_list+0x596/0x830 mm/page_alloc.c:2451 release_pages+0x2113/0x23f0 mm/swap.c:1042 tlb_batch_pages_flush mm/mmu_gather.c:98 [inline] tlb_flush_mmu_free mm/mmu_gather.c:293 [inline] tlb_flush_mmu+0x34c/0x4e0 mm/mmu_gather.c:300 tlb_finish_mmu+0xd4/0x1f0 mm/mmu_gather.c:392 exit_mmap+0x4d3/0xc50 mm/mmap.c:3223 __mmput+0x115/0x3c0 kernel/fork.c:1349 exit_mm+0x21f/0x300 kernel/exit.c:567 do_exit+0x9af/0x2650 kernel/exit.c:861 do_group_exit+0x206/0x2c0 kernel/exit.c:1024 __do_sys_exit_group kernel/exit.c:1035 [inline] __se_sys_exit_group kernel/exit.c:1033 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff88806e71ef80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88806e71f000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88806e71f080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88806e71f100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88806e71f180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================