loop7: detected capacity change from 0 to 32768 ocfs2: Mounting device (7,7) on (node local, slot 0) with ordered data mode. ================================================================== BUG: KASAN: slab-use-after-free in ocfs2_fault+0xe9/0x3d0 fs/ocfs2/mmap.c:41 Read of size 8 at addr ffff888027e1a080 by task syz.7.424/12732 CPU: 1 UID: 0 PID: 12732 Comm: syz.7.424 Not tainted 6.14.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0x16e/0x5b0 mm/kasan/report.c:521 kasan_report+0x143/0x180 mm/kasan/report.c:634 ocfs2_fault+0xe9/0x3d0 fs/ocfs2/mmap.c:41 __do_fault+0x135/0x390 mm/memory.c:4989 do_read_fault mm/memory.c:5409 [inline] do_fault mm/memory.c:5543 [inline] do_pte_missing mm/memory.c:4059 [inline] handle_pte_fault mm/memory.c:5888 [inline] __handle_mm_fault+0x40c6/0x6ef0 mm/memory.c:6031 handle_mm_fault+0x2c1/0x7e0 mm/memory.c:6200 do_user_addr_fault arch/x86/mm/fault.c:1388 [inline] handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x2b9/0x8b0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:fault_in_readable+0x173/0x2d0 mm/gup.c:2241 Code: 00 fc ff df 4c 89 e8 4f 8d ac 25 ff 0f 00 00 49 81 e5 00 f0 ff ff 49 39 c5 72 7a e8 67 fd b6 ff 4c 39 eb 74 7d 4c 89 64 24 08 <44> 8a 23 43 0f b6 04 3e 84 c0 75 18 44 88 64 24 40 48 81 c3 00 10 RSP: 0018:ffffc9000c2f77c0 EFLAGS: 00050287 RAX: ffffffff820ae209 RBX: 0000400000001000 RCX: 0000000000080000 RDX: ffffc9001aca3000 RSI: 000000000000024a RDI: 000000000000024b RBP: ffffc9000c2f7878 R08: ffffffff820ae19c R09: ffffffff84eb2219 R10: 0000000000000002 R11: ffff888025ff0000 R12: 0000000000001000 R13: 0000400000002000 R14: 1ffff9200185ef00 R15: dffffc0000000000 fault_in_iov_iter_readable+0x229/0x280 lib/iov_iter.c:94 generic_perform_write+0x260/0x990 mm/filemap.c:4092 ocfs2_file_write_iter+0x19af/0x2180 fs/ocfs2/file.c:2469 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xacf/0xd10 fs/read_write.c:679 ksys_write+0x18f/0x2b0 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f126d98d169 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:00007f126e858038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f126dba5fa0 RCX: 00007f126d98d169 RDX: 0000000000001006 RSI: 0000400000000940 RDI: 0000000000000004 RBP: 00007f126da0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f126dba5fa0 R15: 00007ffc0152a198 Allocated by task 12732: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4171 vm_area_alloc+0x24/0x1d0 kernel/fork.c:472 __mmap_new_vma mm/vma.c:2345 [inline] __mmap_region mm/vma.c:2461 [inline] mmap_region+0x1b04/0x2fa0 mm/vma.c:2539 do_mmap+0xecc/0x13a0 mm/mmap.c:561 vm_mmap_pgoff+0x2a0/0x530 mm/util.c:578 ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:607 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 25: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4609 [inline] kmem_cache_free+0x195/0x410 mm/slub.c:4711 rcu_do_batch kernel/rcu/tree.c:2546 [inline] rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2802 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 run_ksoftirqd+0xca/0x130 kernel/softirq.c:950 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xaa/0xc0 mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:3065 [inline] call_rcu+0x168/0xac0 kernel/rcu/tree.c:3172 remove_vma mm/vma.c:419 [inline] vms_complete_munmap_vmas+0x65b/0x8f0 mm/vma.c:1202 __mmap_complete mm/vma.c:2411 [inline] __mmap_region mm/vma.c:2477 [inline] mmap_region+0x1998/0x2fa0 mm/vma.c:2539 do_mmap+0xecc/0x13a0 mm/mmap.c:561 vm_mmap_pgoff+0x2a0/0x530 mm/util.c:578 ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:607 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888027e1a000 which belongs to the cache vm_area_struct of size 184 The buggy address is located 128 bytes inside of freed 184-byte region [ffff888027e1a000, ffff888027e1a0b8) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x27e1a memcg:ffff888078e95201 anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801c287b40 ffffea0001663940 dead000000000009 raw: 0000000000000000 0000000000100010 00000000f5000000 ffff888078e95201 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 11929, tgid 11929 (dhcpcd-run-hook), ts 277269872844, free_ts 277245324992 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0x3651/0x37a0 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4740 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab+0x8f/0x3a0 mm/slub.c:2587 new_slab mm/slub.c:2640 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826 __slab_alloc+0x58/0xa0 mm/slub.c:3916 __slab_alloc_node mm/slub.c:3991 [inline] slab_alloc_node mm/slub.c:4152 [inline] kmem_cache_alloc_noprof+0x268/0x380 mm/slub.c:4171 vm_area_alloc+0x24/0x1d0 kernel/fork.c:472 __mmap_new_vma mm/vma.c:2345 [inline] __mmap_region mm/vma.c:2461 [inline] mmap_region+0x1b04/0x2fa0 mm/vma.c:2539 do_mmap+0xecc/0x13a0 mm/mmap.c:561 vm_mmap_pgoff+0x2a0/0x530 mm/util.c:578 ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:607 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 11926 tgid 11925 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe04/0x10e0 mm/page_alloc.c:2660 pagetable_free include/linux/mm.h:2917 [inline] pagetable_dtor_free include/linux/mm.h:3015 [inline] __tlb_remove_table+0x33c/0x420 include/asm-generic/tlb.h:216 __tlb_remove_table_free mm/mmu_gather.c:227 [inline] tlb_remove_table_rcu+0x76/0xf0 mm/mmu_gather.c:282 rcu_do_batch kernel/rcu/tree.c:2546 [inline] rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2802 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 Memory state around the buggy address: ffff888027e19f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888027e1a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888027e1a080: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fa ^ ffff888027e1a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888027e1a180: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb ================================================================== ---------------- Code disassembly (best guess), 3 bytes skipped: 0: df 4c 89 e8 fisttps -0x18(%rcx,%rcx,4) 4: 4f 8d ac 25 ff 0f 00 lea 0xfff(%r13,%r12,1),%r13 b: 00 c: 49 81 e5 00 f0 ff ff and $0xfffffffffffff000,%r13 13: 49 39 c5 cmp %rax,%r13 16: 72 7a jb 0x92 18: e8 67 fd b6 ff call 0xffb6fd84 1d: 4c 39 eb cmp %r13,%rbx 20: 74 7d je 0x9f 22: 4c 89 64 24 08 mov %r12,0x8(%rsp) * 27: 44 8a 23 mov (%rbx),%r12b <-- trapping instruction 2a: 43 0f b6 04 3e movzbl (%r14,%r15,1),%eax 2f: 84 c0 test %al,%al 31: 75 18 jne 0x4b 33: 44 88 64 24 40 mov %r12b,0x40(%rsp) 38: 48 rex.W 39: 81 .byte 0x81 3a: c3 ret 3b: 00 10 add %dl,(%rax)