================================================================== BUG: KASAN: slab-use-after-free in ocfs2_fault+0xe9/0x3d0 fs/ocfs2/mmap.c:41 Read of size 8 at addr ffff8880345a9368 by task syz.9.126/7362 CPU: 1 UID: 0 PID: 7362 Comm: syz.9.126 Not tainted 6.13.0-rc2-syzkaller-00018-g7cb1b4663150 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 ocfs2_fault+0xe9/0x3d0 fs/ocfs2/mmap.c:41 __do_fault+0x135/0x390 mm/memory.c:4907 do_read_fault mm/memory.c:5322 [inline] do_fault mm/memory.c:5456 [inline] do_pte_missing mm/memory.c:3979 [inline] handle_pte_fault+0x39eb/0x5ed0 mm/memory.c:5801 __handle_mm_fault mm/memory.c:5944 [inline] handle_mm_fault+0x1053/0x1ad0 mm/memory.c:6112 do_user_addr_fault arch/x86/mm/fault.c:1389 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x2b9/0x8b0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:fault_in_readable+0x173/0x2d0 mm/gup.c:2244 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 dc b7 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:ffffc900052677c0 EFLAGS: 00050287 RAX: ffffffff81e78189 RBX: 0000000020003000 RCX: 0000000000080000 RDX: ffffc9000cd9a000 RSI: 000000000000537a RDI: 000000000000537b RBP: ffffc90005267878 R08: ffffffff81e7811c R09: ffffffff84b7a4e9 R10: 0000000000000002 R11: ffff888027051e00 R12: 0000000000000200 R13: 0000000020004000 R14: 1ffff92000a4cf00 R15: dffffc0000000000 fault_in_iov_iter_readable+0x229/0x280 lib/iov_iter.c:94 generic_perform_write+0x260/0x990 mm/filemap.c:4045 ocfs2_file_write_iter+0x19af/0x2180 fs/ocfs2/file.c:2469 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xaeb/0xd30 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: 0033:0x7fef6037ff19 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:00007fef61159058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fef60545fa0 RCX: 00007fef6037ff19 RDX: 00000000175d9003 RSI: 0000000020000200 RDI: 0000000000000004 RBP: 00007fef603f3cc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fef60545fa0 R15: 00007fff8c503248 Allocated by task 7362: 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:4104 [inline] slab_alloc_node mm/slub.c:4153 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4160 vm_area_alloc+0x24/0x1d0 kernel/fork.c:472 __mmap_new_vma mm/vma.c:2340 [inline] __mmap_region+0x196e/0x2cd0 mm/vma.c:2456 mmap_region+0x226/0x2c0 mm/mmap.c:1348 do_mmap+0x8f0/0x1000 mm/mmap.c:496 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:580 ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:542 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 7374: 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:582 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:2338 [inline] slab_free mm/slub.c:4598 [inline] kmem_cache_free+0x195/0x410 mm/slub.c:4700 rcu_do_batch kernel/rcu/tree.c:2567 [inline] rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823 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 Last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:544 __call_rcu_common kernel/rcu/tree.c:3086 [inline] call_rcu+0x167/0xa70 kernel/rcu/tree.c:3190 remove_vma mm/vma.c:387 [inline] vms_complete_munmap_vmas+0x65b/0x8f0 mm/vma.c:1201 __mmap_complete mm/vma.c:2406 [inline] __mmap_region+0x17e3/0x2cd0 mm/vma.c:2469 mmap_region+0x1d0/0x2c0 mm/mmap.c:1348 do_mmap+0x8f0/0x1000 mm/mmap.c:496 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:580 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 ffff8880345a92e8 which belongs to the cache vm_area_struct of size 184 The buggy address is located 128 bytes inside of freed 184-byte region [ffff8880345a92e8, ffff8880345a93a0) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x345a9 memcg:ffff88805a73f401 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801bafeb40 ffffea0000bfe6c0 dead000000000002 raw: 0000000000000000 0000000000100010 00000001f5000000 ffff88805a73f401 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 7073, tgid 7073 (udevadm), ts 137621552691, free_ts 137023099277 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556 prep_new_page mm/page_alloc.c:1564 [inline] get_page_from_freelist+0x3651/0x37a0 mm/page_alloc.c:3474 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2269 alloc_slab_page+0x6a/0x110 mm/slub.c:2408 allocate_slab+0x5a/0x2b0 mm/slub.c:2574 new_slab mm/slub.c:2627 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3815 __slab_alloc+0x58/0xa0 mm/slub.c:3905 __slab_alloc_node mm/slub.c:3980 [inline] slab_alloc_node mm/slub.c:4141 [inline] kmem_cache_alloc_noprof+0x268/0x380 mm/slub.c:4160 vm_area_dup+0x27/0x290 kernel/fork.c:487 __split_vma+0x1cb/0xc50 mm/vma.c:434 split_vma mm/vma.c:510 [inline] vma_modify+0x244/0x330 mm/vma.c:1528 vma_modify_flags+0x3a5/0x430 mm/vma.c:1546 mprotect_fixup+0x45a/0xaa0 mm/mprotect.c:666 do_mprotect_pkey+0x8d7/0xd70 mm/mprotect.c:840 __do_sys_mprotect mm/mprotect.c:861 [inline] __se_sys_mprotect mm/mprotect.c:858 [inline] __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:858 page last free pid 6168 tgid 6168 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_folios+0xe23/0x1890 mm/page_alloc.c:2704 folios_put_refs+0x76c/0x860 mm/swap.c:962 folio_batch_release include/linux/pagevec.h:101 [inline] mapping_try_invalidate+0x3f7/0x550 mm/truncate.c:501 btrfs_close_bdev fs/btrfs/volumes.c:1188 [inline] btrfs_close_one_device fs/btrfs/volumes.c:1212 [inline] close_fs_devices+0x442/0x890 fs/btrfs/volumes.c:1255 btrfs_close_devices+0xc8/0x5c0 fs/btrfs/volumes.c:1270 close_ctree+0x7d3/0xd60 fs/btrfs/disk-io.c:4381 generic_shutdown_super+0x139/0x2d0 fs/super.c:642 kill_anon_super+0x3b/0x70 fs/super.c:1237 btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2112 deactivate_locked_super+0xc4/0x130 fs/super.c:473 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373 task_work_run+0x24f/0x310 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880345a9200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880345a9280: fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb >ffff8880345a9300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880345a9380: fb fb fb fb fc fc fc fc fc fc fc fc 00 00 00 00 ffff8880345a9400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ---------------- 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 dc b7 ff call 0xffb7dc84 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)