================================================================== BUG: KASAN: slab-use-after-free in ocfs2_fault+0xe9/0x3d0 fs/ocfs2/mmap.c:41 Read of size 8 at addr ffff88805bab8b28 by task syz.1.172/7344 CPU: 1 UID: 0 PID: 7344 Comm: syz.1.172 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #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+0x111/0x2d0 mm/gup.c:2237 Code: 8b 6c 24 18 4c 89 ee 48 81 e6 ff 0f 00 00 31 ff e8 64 e1 b7 ff 4c 89 e8 48 25 ff 0f 00 00 74 34 49 bf 00 00 00 00 00 fc ff df <41> 8a 5d 00 e8 66 dc b7 ff 43 0f b6 04 3e 84 c0 0f 85 61 01 00 00 RSP: 0018:ffffc9000ba3f7c0 EFLAGS: 00050202 RAX: 0000000000000980 RBX: 0000000020001983 RCX: ffff8880275ebc00 RDX: ffffc9000d13a000 RSI: 0000000000000980 RDI: 0000000000000000 RBP: ffffc9000ba3f878 R08: ffffffff81e7974c R09: ffffffff84b7d889 R10: 0000000000000002 R11: ffff8880275ebc00 R12: 0000000000000003 R13: 0000000020001980 R14: 1ffff92001747f00 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: 0033:0x7f9a0c785d29 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:00007f9a0d610038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f9a0c975fa0 RCX: 00007f9a0c785d29 RDX: 0000000000000003 RSI: 0000000020001980 RDI: 0000000000000005 RBP: 00007f9a0c801b08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f9a0c975fa0 R15: 00007ffd0ac9d6f8 Allocated by task 7363: 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:4119 [inline] slab_alloc_node mm/slub.c:4168 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4175 vm_area_alloc+0x24/0x1d0 kernel/fork.c:472 __mmap_new_vma mm/vma.c:2340 [inline] __mmap_region+0x1961/0x2d30 mm/vma.c:2456 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 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 16: 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:2353 [inline] slab_free mm/slub.c:4613 [inline] kmem_cache_free+0x195/0x410 mm/slub.c:4715 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 run_ksoftirqd+0xca/0x130 kernel/softirq.c:950 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 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+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 do_vmi_align_munmap+0x5ef/0x6f0 mm/vma.c:1444 do_vmi_munmap+0x24e/0x2d0 mm/vma.c:1492 __vm_munmap+0x24c/0x480 mm/mmap.c:1368 __do_sys_munmap mm/mmap.c:1385 [inline] __se_sys_munmap mm/mmap.c:1382 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1382 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 ffff88805bab8aa8 which belongs to the cache vm_area_struct of size 184 The buggy address is located 128 bytes inside of freed 184-byte region [ffff88805bab8aa8, ffff88805bab8b60) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5bab8 memcg:ffff888078c73601 anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801bafeb40 ffffea0001e39000 0000000000000005 raw: 0000000000000000 0000000000100010 00000001f5000000 ffff888078c73601 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 7211, tgid 7211 (dhcpcd-run-hook), ts 151931692675, free_ts 151928607948 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1558 prep_new_page mm/page_alloc.c:1566 [inline] get_page_from_freelist+0x3651/0x37a0 mm/page_alloc.c:3476 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4753 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2269 alloc_slab_page+0x6a/0x110 mm/slub.c:2423 allocate_slab+0x5a/0x2b0 mm/slub.c:2589 new_slab mm/slub.c:2642 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3830 __slab_alloc+0x58/0xa0 mm/slub.c:3920 __slab_alloc_node mm/slub.c:3995 [inline] slab_alloc_node mm/slub.c:4156 [inline] kmem_cache_alloc_noprof+0x268/0x380 mm/slub.c:4175 vm_area_dup+0x27/0x290 kernel/fork.c:487 dup_mmap kernel/fork.c:694 [inline] dup_mm kernel/fork.c:1691 [inline] copy_mm+0xb95/0x1fd0 kernel/fork.c:1743 copy_process+0x1845/0x3d50 kernel/fork.c:2394 kernel_clone+0x223/0x870 kernel/fork.c:2806 __do_sys_clone kernel/fork.c:2949 [inline] __se_sys_clone kernel/fork.c:2933 [inline] __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2933 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 7223 tgid 7223 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:2706 folios_put_refs+0x76c/0x860 mm/swap.c:962 free_pages_and_swap_cache+0x2ea/0x690 mm/swap_state.c:332 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:366 [inline] tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:373 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465 exit_mmap+0x496/0xc20 mm/mmap.c:1681 __mmput+0x115/0x3b0 kernel/fork.c:1348 exit_mm+0x220/0x310 kernel/exit.c:570 do_exit+0x9ad/0x28e0 kernel/exit.c:925 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232 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 Memory state around the buggy address: ffff88805bab8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff88805bab8a80: fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb >ffff88805bab8b00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff88805bab8b80: fc fc fc fc 00 00 00 00 00 00 00 00 00 00 00 00 ffff88805bab8c00: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 8b 6c 24 18 mov 0x18(%rsp),%ebp 4: 4c 89 ee mov %r13,%rsi 7: 48 81 e6 ff 0f 00 00 and $0xfff,%rsi e: 31 ff xor %edi,%edi 10: e8 64 e1 b7 ff call 0xffb7e179 15: 4c 89 e8 mov %r13,%rax 18: 48 25 ff 0f 00 00 and $0xfff,%rax 1e: 74 34 je 0x54 20: 49 bf 00 00 00 00 00 movabs $0xdffffc0000000000,%r15 27: fc ff df * 2a: 41 8a 5d 00 mov 0x0(%r13),%bl <-- trapping instruction 2e: e8 66 dc b7 ff call 0xffb7dc99 33: 43 0f b6 04 3e movzbl (%r14,%r15,1),%eax 38: 84 c0 test %al,%al 3a: 0f 85 61 01 00 00 jne 0x1a1