================================================================== BUG: KASAN: slab-use-after-free in ocfs2_fault+0xe9/0x3d0 fs/ocfs2/mmap.c:41 Read of size 8 at addr ffff888069197270 by task syz.1.601/12274 CPU: 0 UID: 0 PID: 12274 Comm: syz.1.601 Not tainted 6.13.0-rc2-syzkaller-00036-g231825b2e1ff #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 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 e7 da 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:ffffc90004a477c0 EFLAGS: 00050287 RAX: ffffffff81e78309 RBX: 0000000020003000 RCX: 0000000000080000 RDX: ffffc9000c5ca000 RSI: 0000000000002b99 RDI: 0000000000002b9a RBP: ffffc90004a47878 R08: ffffffff81e7829c R09: ffffffff84b7a729 R10: 0000000000000002 R11: ffff888026d3da00 R12: 0000000000000200 R13: 0000000020004000 R14: 1ffff92000948f00 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: 0033:0x7fb926985d19 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:00007fb927763038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fb926b75fa0 RCX: 00007fb926985d19 RDX: 00000000175d9003 RSI: 0000000020000200 RDI: 0000000000000004 RBP: 00007fb926a01a20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb926b75fa0 R15: 00007ffc51b6d268 Allocated by task 12274: 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 12262: 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 ffff8880691971f0 which belongs to the cache vm_area_struct of size 184 The buggy address is located 128 bytes inside of freed 184-byte region [ffff8880691971f0, ffff8880691972a8) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x69197 memcg:ffff88802efacb01 anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801bafeb40 ffffea0001a46500 000000000000000d raw: 0000000000000000 0000000000100010 00000001f5000000 ffff88802efacb01 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 12097, tgid 12097 (dhcpcd-run-hook), ts 370370988356, free_ts 370364498240 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 dup_mmap kernel/fork.c:697 [inline] dup_mm kernel/fork.c:1695 [inline] copy_mm+0xc1d/0x1f90 kernel/fork.c:1744 copy_process+0x1845/0x3d50 kernel/fork.c:2395 kernel_clone+0x223/0x870 kernel/fork.c:2807 __do_sys_clone kernel/fork.c:2950 [inline] __se_sys_clone kernel/fork.c:2934 [inline] __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2934 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 11271 tgid 11271 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0xd2c/0x1000 mm/page_alloc.c:2657 vfree+0x186/0x2e0 mm/vmalloc.c:3382 kcov_put kernel/kcov.c:439 [inline] kcov_close+0x28/0x50 kernel/kcov.c:535 __fput+0x23c/0xa50 fs/file_table.c:450 task_work_run+0x24f/0x310 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:938 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: ffff888069197100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888069197180: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fa fb >ffff888069197200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888069197280: fb fb fb fb fb fc fc fc fc fc fc fc fc 00 00 00 ffff888069197300: 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 e7 da b7 ff call 0xffb7db04 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)