================================================================== BUG: KASAN: use-after-free in atomic_dec_and_test include/asm-generic/atomic-instrumented.h:222 [inline] BUG: KASAN: use-after-free in fib6_info_release include/net/ip6_fib.h:286 [inline] BUG: KASAN: use-after-free in ip6_dst_destroy+0x2a4/0x4e0 net/ipv6/route.c:383 Write of size 4 at addr ffff8801d869a72c by task blkid/20858 CPU: 1 PID: 20858 Comm: blkid Not tainted 4.18.0-rc3+ #2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267 kasan_check_write+0x14/0x20 mm/kasan/kasan.c:278 atomic_dec_and_test include/asm-generic/atomic-instrumented.h:222 [inline] fib6_info_release include/net/ip6_fib.h:286 [inline] ip6_dst_destroy+0x2a4/0x4e0 net/ipv6/route.c:383 dst_destroy+0x118/0x3c0 net/core/dst.c:132 dst_destroy_rcu+0x16/0x20 net/core/dst.c:154 __rcu_reclaim kernel/rcu/rcu.h:178 [inline] rcu_do_batch kernel/rcu/tree.c:2558 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2818 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2785 [inline] rcu_process_callbacks+0xed5/0x1850 kernel/rcu/tree.c:2802 __do_softirq+0x2e8/0xb17 kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x1d1/0x200 kernel/softirq.c:408 exiting_irq arch/x86/include/asm/apic.h:527 [inline] smp_apic_timer_interrupt+0x186/0x730 arch/x86/kernel/apic/apic.c:1052 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:23 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:67 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x50 kernel/kcov.c:101 Code: 7c 10 e0 4a 89 74 10 e8 4a 89 54 10 f0 4a 89 4c d8 20 4c 89 08 5d c3 66 90 55 65 48 8b 04 25 40 ee 01 00 65 8b 15 ef e1 85 7e <48> 89 e5 81 e2 00 01 1f 00 48 8b 75 08 75 2b 8b 90 90 12 00 00 83 RSP: 0018:ffff880198347838 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffff8801aed62140 RBX: ffff8801ad839080 RCX: ffffffff81c43500 RDX: 0000000080000000 RSI: ffffffff81c43514 RDI: ffff8801ad839080 RBP: ffff880198347860 R08: ffff8801aed62140 R09: ffffed0035b0721e R10: ffffed0035b0721e R11: ffff8801ad8390f7 R12: 0000000000000001 R13: ffff8801ad839080 R14: ffff880198347c00 R15: dffffc0000000000 netlink: 'syz-executor2': attribute type 3 has an invalid length. put_filp+0x4c/0xb2 fs/file_table.c:306 path_openat+0xc63/0x4e10 fs/namei.c:3552 netlink: 'syz-executor2': attribute type 3 has an invalid length. do_filp_open+0x255/0x380 fs/namei.c:3574 do_sys_open+0x584/0x760 fs/open.c:1101 __do_sys_openat fs/open.c:1128 [inline] __se_sys_openat fs/open.c:1122 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1122 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f23726fd1c8 Code: 00 00 48 83 ec 78 45 31 d2 f6 c2 40 48 89 4c 24 58 75 27 8b 05 35 a4 2b 00 85 c0 75 54 48 63 d2 48 63 ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 2e 48 83 c4 78 c3 0f 1f 00 48 8d 84 24 80 00 RSP: 002b:00007ffe0e36c420 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffe0e36c9d0 RCX: 00007f23726fd1c8 RDX: 0000000000000000 RSI: 00007f23729d3ea0 RDI: 0000000000000004 RBP: 00007f23729d5064 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f23729d3ea0 R13: 0000000000000000 R14: 00007f2372bde820 R15: 00007f23729d42a2 Allocated by task 20749: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620 kmalloc include/linux/slab.h:513 [inline] kzalloc include/linux/slab.h:707 [inline] fib6_info_alloc+0xc3/0x290 net/ipv6/ip6_fib.c:152 ip6_route_info_create+0x7aa/0x2c30 net/ipv6/route.c:3010 ip6_route_add+0x23/0xc0 net/ipv6/route.c:3151 rt6_add_route_info+0x533/0x6f0 net/ipv6/route.c:3508 rt6_route_rcv+0x625/0x880 net/ipv6/route.c:846 ndisc_router_discovery+0x16e7/0x3370 net/ipv6/ndisc.c:1443 ndisc_rcv+0x565/0x660 net/ipv6/ndisc.c:1751 icmpv6_rcv+0x1456/0x1a60 net/ipv6/icmp.c:881 ip6_input_finish+0x407/0x1a40 net/ipv6/ip6_input.c:284 NF_HOOK include/linux/netfilter.h:287 [inline] ip6_input+0xe9/0x600 net/ipv6/ip6_input.c:327 ip6_mc_input+0x45a/0xcf0 net/ipv6/ip6_input.c:404 dst_input include/net/dst.h:450 [inline] ip6_rcv_finish+0x2ab/0xa30 net/ipv6/ip6_input.c:71 NF_HOOK include/linux/netfilter.h:287 [inline] ipv6_rcv+0xec0/0x2060 net/ipv6/ip6_input.c:208 __netif_receive_skb_core+0x2488/0x3680 net/core/dev.c:4628 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:4693 netif_receive_skb_internal+0x12e/0x7d0 net/core/dev.c:4767 netif_receive_skb+0xbf/0x420 net/core/dev.c:4791 tun_rx_batched.isra.55+0x4ba/0x8c0 drivers/net/tun.c:1571 tun_get_user+0x2af1/0x42f0 drivers/net/tun.c:1981 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:2009 call_write_iter include/linux/fs.h:1793 [inline] do_iter_readv_writev+0x897/0xa90 fs/read_write.c:680 do_iter_write+0x185/0x5f0 fs/read_write.c:959 vfs_writev+0x1f1/0x360 fs/read_write.c:1004 do_writev+0x11a/0x310 fs/read_write.c:1039 __do_sys_writev fs/read_write.c:1112 [inline] __se_sys_writev fs/read_write.c:1109 [inline] __x64_sys_writev+0x75/0xb0 fs/read_write.c:1109 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 20858: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xd9/0x260 mm/slab.c:3813 fib6_info_destroy_rcu+0x2ab/0x360 net/ipv6/ip6_fib.c:208 __rcu_reclaim kernel/rcu/rcu.h:178 [inline] rcu_do_batch kernel/rcu/tree.c:2558 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2818 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2785 [inline] rcu_process_callbacks+0xed5/0x1850 kernel/rcu/tree.c:2802 __do_softirq+0x2e8/0xb17 kernel/softirq.c:288 The buggy address belongs to the object at ffff8801d869a700 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 44 bytes inside of 256-byte region [ffff8801d869a700, ffff8801d869a800) The buggy address belongs to the page: page:ffffea000761a680 count:1 mapcount:0 mapping:ffff8801da8007c0 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea0006e55b48 ffffea0006fad908 ffff8801da8007c0 raw: 0000000000000000 ffff8801d869a0c0 000000010000000c 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d869a600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8801d869a680: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801d869a700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d869a780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d869a800: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ==================================================================