================================================================== BUG: KASAN: slab-use-after-free in ocfs2_fault+0xe8/0x3e0 fs/ocfs2/mmap.c:41 Read of size 8 at addr ffff888011c87b98 by task syz.0.0/5328 CPU: 0 UID: 0 PID: 5328 Comm: syz.0.0 Not tainted 6.15.0-rc1-syzkaller-00060-ga24588245776 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 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+0xe8/0x3e0 fs/ocfs2/mmap.c:41 __do_fault+0x135/0x390 mm/memory.c:5098 do_shared_fault mm/memory.c:5582 [inline] do_fault mm/memory.c:5656 [inline] do_pte_missing mm/memory.c:4160 [inline] handle_pte_fault+0xfcc/0x61c0 mm/memory.c:5997 __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1129/0x1bf0 mm/memory.c:6309 do_user_addr_fault arch/x86/mm/fault.c:1388 [inline] handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x2bb/0x920 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f794cf5690c Code: 00 00 00 74 a0 83 f9 c0 0f 87 56 fe ff ff 62 e1 fe 28 6f 4e 01 48 29 fe 48 83 c7 3f 49 8d 0c 10 48 83 e7 c0 48 01 fe 48 29 f9 a4 62 c1 fe 28 7f 00 62 c1 fe 28 7f 48 01 c3 0f 1f 40 00 4c 8b RSP: 002b:00007ffd1a6d0ff8 EFLAGS: 00010202 RAX: 0000200000020940 RBX: 0000000000000004 RCX: 000000000001f773 RDX: 000000000001f773 RSI: 00007f794ca2ce89 RDI: 0000200000020940 RBP: 00007ffd1a6d10c8 R08: 0000200000020940 R09: 000000000000000f R10: 0000000000000000 R11: 0000000000000002 R12: 00007f794d1a608c R13: 00007f794d1a6080 R14: fffffffffffffffe R15: 0000000000000006 Allocated by task 5329: 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:4151 [inline] slab_alloc_node mm/slub.c:4200 [inline] kmem_cache_alloc_noprof+0x1e1/0x390 mm/slub.c:4207 vm_area_alloc+0x24/0x140 kernel/fork.c:441 __mmap_new_vma mm/vma.c:2359 [inline] __mmap_region mm/vma.c:2476 [inline] mmap_region+0x1acb/0x2ea0 mm/vma.c:2554 do_mmap+0xd42/0x1420 mm/mmap.c:561 vm_mmap_pgoff+0x2a2/0x530 mm/util.c:579 ksys_mmap_pgoff+0x4ee/0x720 mm/mmap.c:607 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5329: 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:2389 [inline] slab_free_after_rcu_debug+0x11a/0x280 mm/slub.c:4696 rcu_do_batch kernel/rcu/tree.c:2568 [inline] rcu_core+0xaac/0x17a0 kernel/rcu/tree.c:2824 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xfb/0x220 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 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+0xbf/0xd0 mm/kasan/generic.c:548 slab_free_hook mm/slub.c:2350 [inline] slab_free mm/slub.c:4646 [inline] kmem_cache_free+0x2ff/0x410 mm/slub.c:4748 remove_vma mm/vma.c:430 [inline] vms_complete_munmap_vmas+0x655/0x8f0 mm/vma.c:1216 __mmap_complete mm/vma.c:2426 [inline] __mmap_region mm/vma.c:2492 [inline] mmap_region+0x19bc/0x2ea0 mm/vma.c:2554 do_mmap+0xd42/0x1420 mm/mmap.c:561 vm_mmap_pgoff+0x2a2/0x530 mm/util.c:579 ksys_mmap_pgoff+0x4ee/0x720 mm/mmap.c:607 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888011c87b40 which belongs to the cache vm_area_struct of size 256 The buggy address is located 88 bytes inside of freed 256-byte region [ffff888011c87b40, ffff888011c87c40) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11c87 memcg:ffff8880121b2d01 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801c2a0b40 ffffea000047a000 dead000000000004 raw: 0000000000000000 00000000000c000c 00000000f5000000 ffff8880121b2d01 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 4707, tgid 4707 (rcS), ts 25022542174, free_ts 24466344863 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1717 prep_new_page mm/page_alloc.c:1725 [inline] get_page_from_freelist+0x352b/0x36c0 mm/page_alloc.c:3652 __alloc_frozen_pages_noprof+0x211/0x5b0 mm/page_alloc.c:4934 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2459 [inline] allocate_slab+0x8f/0x3a0 mm/slub.c:2623 new_slab mm/slub.c:2676 [inline] ___slab_alloc+0xc3b/0x1500 mm/slub.c:3862 __slab_alloc+0x58/0xa0 mm/slub.c:3952 __slab_alloc_node mm/slub.c:4027 [inline] slab_alloc_node mm/slub.c:4188 [inline] kmem_cache_alloc_noprof+0x270/0x390 mm/slub.c:4207 vm_area_dup+0x2b/0x5b0 kernel/fork.c:488 __split_vma+0x1b8/0xb20 mm/vma.c:477 vms_gather_munmap_vmas+0x325/0x13d0 mm/vma.c:1282 __mmap_prepare mm/vma.c:2260 [inline] __mmap_region mm/vma.c:2463 [inline] mmap_region+0xa13/0x2ea0 mm/vma.c:2554 do_mmap+0xd42/0x1420 mm/mmap.c:561 vm_mmap_pgoff+0x2a2/0x530 mm/util.c:579 ksys_mmap_pgoff+0x4ee/0x720 mm/mmap.c:607 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] __free_frozen_pages+0xde8/0x10a0 mm/page_alloc.c:2680 __free_pages mm/page_alloc.c:5044 [inline] free_reserved_page+0xce/0x120 mm/page_alloc.c:5947 free_reserved_area+0x51/0xf0 mm/page_alloc.c:5933 free_init_pages arch/x86/mm/init.c:937 [inline] free_kernel_image_pages arch/x86/mm/init.c:953 [inline] free_initmem+0x9a/0x110 arch/x86/mm/init.c:980 kernel_init+0x31/0x2b0 init/main.c:1466 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888011c87a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888011c87b00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff888011c87b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888011c87c00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888011c87c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================