================================================================== BUG: KASAN: slab-use-after-free in ocfs2_fault+0xe9/0x3d0 fs/ocfs2/mmap.c:41 Read of size 8 at addr ffff8880781e6c20 by task syz.9.661/12242 CPU: 0 UID: 0 PID: 12242 Comm: syz.9.661 Not tainted 6.12.0-syzkaller-07749-g28eb75e178d3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 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:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 ocfs2_fault+0xe9/0x3d0 fs/ocfs2/mmap.c:41 __do_fault+0x135/0x460 mm/memory.c:4882 do_read_fault mm/memory.c:5297 [inline] do_fault mm/memory.c:5431 [inline] do_pte_missing mm/memory.c:3965 [inline] handle_pte_fault+0x2d1c/0x6820 mm/memory.c:5766 __handle_mm_fault mm/memory.c:5909 [inline] handle_mm_fault+0x1053/0x1ad0 mm/memory.c:6077 do_user_addr_fault arch/x86/mm/fault.c:1389 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x2b9/0x8c0 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:2235 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 f7 a5 b5 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:ffffc90004f177c0 EFLAGS: 00050287 RAX: ffffffff81dfa639 RBX: 0000000020001000 RCX: 0000000000080000 RDX: ffffc90011a16000 RSI: 00000000000001b3 RDI: 00000000000001b4 RBP: ffffc90004f17878 R08: ffffffff81dfa5cc R09: ffffffff84aa3cb9 R10: 0000000000000002 R11: ffff8880331bda00 R12: 0000000000001000 R13: 0000000020002000 R14: 1ffff920009e2f00 R15: dffffc0000000000 fault_in_iov_iter_readable+0x229/0x280 lib/iov_iter.c:94 generic_perform_write+0x259/0x6d0 mm/filemap.c:4046 ocfs2_file_write_iter+0x17b1/0x1f50 fs/ocfs2/file.c:2467 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: 0033:0x7fdc11b7e819 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:00007fdc129ac038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fdc11d36080 RCX: 00007fdc11b7e819 RDX: 0000000000001006 RSI: 0000000020000940 RDI: 0000000000000007 RBP: 00007fdc11bf175e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fdc11d36080 R15: 00007ffc87b41a78 Allocated by task 12242: 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:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141 vm_area_alloc+0x24/0x1d0 kernel/fork.c:473 __mmap_region mm/mmap.c:1435 [inline] mmap_region+0x113b/0x23f0 mm/mmap.c:1603 do_mmap+0x8f0/0x1000 mm/mmap.c:496 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588 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:579 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:230 [inline] slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4579 [inline] kmem_cache_free+0x1a2/0x420 mm/slub.c:4681 rcu_do_batch kernel/rcu/tree.c:2567 [inline] rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:943 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:541 __call_rcu_common kernel/rcu/tree.c:3086 [inline] call_rcu+0x167/0xa70 kernel/rcu/tree.c:3190 remove_vma mm/vma.c:336 [inline] vms_complete_munmap_vmas+0x65f/0x8f0 mm/vma.c:1160 __mmap_region mm/mmap.c:1530 [inline] mmap_region+0x10b5/0x23f0 mm/mmap.c:1603 do_mmap+0x8f0/0x1000 mm/mmap.c:496 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588 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 The buggy address belongs to the object at ffff8880781e6ba0 which belongs to the cache vm_area_struct of size 184 The buggy address is located 128 bytes inside of freed 184-byte region [ffff8880781e6ba0, ffff8880781e6c58) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x781e6 memcg:ffff888027f3a401 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801bafdb40 ffffea0000c08b40 dead00000000000a raw: 0000000000000000 0000000000100010 00000001f5000000 ffff888027f3a401 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 11871, tgid 11871 (sed), ts 519420335651, free_ts 519245604938 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+0x363e/0x3790 mm/page_alloc.c:3474 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 alloc_slab_page+0x6a/0x140 mm/slub.c:2412 allocate_slab+0x5a/0x2f0 mm/slub.c:2578 new_slab mm/slub.c:2631 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818 __slab_alloc+0x58/0xa0 mm/slub.c:3908 __slab_alloc_node mm/slub.c:3961 [inline] slab_alloc_node mm/slub.c:4122 [inline] kmem_cache_alloc_noprof+0x1c1/0x2a0 mm/slub.c:4141 vm_area_alloc+0x24/0x1d0 kernel/fork.c:473 __mmap_region mm/mmap.c:1435 [inline] mmap_region+0x113b/0x23f0 mm/mmap.c:1603 do_mmap+0x8f0/0x1000 mm/mmap.c:496 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588 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 11344 tgid 11344 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0xded/0x1130 mm/page_alloc.c:2657 vfree+0x186/0x2e0 mm/vmalloc.c:3361 delayed_vfree_work+0x56/0x80 mm/vmalloc.c:3282 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 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 Memory state around the buggy address: ffff8880781e6b00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880781e6b80: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb >ffff8880781e6c00: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ^ ffff8880781e6c80: fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb ffff8880781e6d00: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc ================================================================== ---------------- 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 f7 a5 b5 ff call 0xffb5a614 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)