================================================================== BUG: KASAN: use-after-free in ocfs2_find_victim_chain fs/ocfs2/suballoc.c:1447 [inline] BUG: KASAN: use-after-free in ocfs2_claim_suballoc_bits+0x8b2/0x2450 fs/ocfs2/suballoc.c:1996 Read of size 4 at addr ffff88804b84a000 by task syz.0.15/5759 CPU: 0 UID: 0 PID: 5759 Comm: syz.0.15 Not tainted syzkaller #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_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 ocfs2_find_victim_chain fs/ocfs2/suballoc.c:1447 [inline] ocfs2_claim_suballoc_bits+0x8b2/0x2450 fs/ocfs2/suballoc.c:1996 ocfs2_claim_metadata+0x178/0x4c0 fs/ocfs2/suballoc.c:2082 ocfs2_create_refcount_tree+0x54f/0x1250 fs/ocfs2/refcounttree.c:591 ocfs2_reflink_remap_blocks+0x2ea/0x1930 fs/ocfs2/refcounttree.c:4646 ocfs2_remap_file_range+0x4b7/0x730 fs/ocfs2/file.c:2740 vfs_copy_file_range+0xd53/0x1310 fs/read_write.c:1591 __do_sys_copy_file_range fs/read_write.c:1677 [inline] __se_sys_copy_file_range+0x2fb/0x470 fs/read_write.c:1644 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f196af79e79 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:00007f196bd79038 EFLAGS: 00000246 ORIG_RAX: 0000000000000146 RAX: ffffffffffffffda RBX: 00007f196b115f80 RCX: 00007f196af79e79 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 00007f196afe7916 R08: 0000000000000006 R09: 0000000000000000 R10: 00000000200000c0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f196b115f80 R15: 00007ffca5e7e648 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88804b84af00 pfn:0x4b84a flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff) page_type: f0(buddy) raw: 04fff00000000000 ffffea00015d5a88 ffffea0000ce7f08 0000000000000000 raw: ffff88804b84af00 0000000000000001 00000000f0000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Unmovable, gfp_mask 0x440dc0(GFP_KERNEL_ACCOUNT|__GFP_ZERO|__GFP_COMP), pid 5048, tgid 5048 (dhcpcd), ts 117735930184, free_ts 144333690920 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline] alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2507 pagetable_alloc_noprof include/linux/mm.h:2881 [inline] __pud_alloc_one_noprof include/asm-generic/pgalloc.h:177 [inline] pud_alloc_one_noprof include/asm-generic/pgalloc.h:198 [inline] __pud_alloc+0x3a/0x260 mm/memory.c:6426 pud_alloc include/linux/mm.h:2838 [inline] copy_pud_range mm/memory.c:1278 [inline] copy_p4d_range mm/memory.c:1322 [inline] copy_page_range+0xcb0/0x1270 mm/memory.c:1410 dup_mmap+0xf57/0x1ac0 mm/mmap.c:1834 dup_mm kernel/fork.c:1485 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1537 copy_process+0x1706/0x3c00 kernel/fork.c:2175 kernel_clone+0x21e/0x840 kernel/fork.c:2605 __do_sys_clone kernel/fork.c:2748 [inline] __se_sys_clone kernel/fork.c:2732 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2732 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 1047 tgid 1047 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895 pagetable_free include/linux/mm.h:2898 [inline] pagetable_dtor_free include/linux/mm.h:2996 [inline] __tlb_remove_table+0x2d2/0x3b0 include/asm-generic/tlb.h:220 __tlb_remove_table_free mm/mmu_gather.c:227 [inline] tlb_remove_table_rcu+0x85/0x100 mm/mmu_gather.c:290 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xcab/0x1770 kernel/rcu/tree.c:2861 handle_softirqs+0x283/0x870 kernel/softirq.c:579 do_softirq+0xec/0x180 kernel/softirq.c:480 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_nc_purge_paths+0x318/0x3b0 net/batman-adv/network-coding.c:471 batadv_nc_worker+0x328/0x610 net/batman-adv/network-coding.c:720 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88804b849f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88804b849f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88804b84a000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88804b84a080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88804b84a100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================