netlink: 9 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 'syz-executor4': attribute type 21 has an invalid length. ================================================================== netlink: 9 bytes leftover after parsing attributes in process `syz-executor0'. BUG: KASAN: null-ptr-deref in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] BUG: KASAN: null-ptr-deref in refcount_sub_and_test_checked+0x9d/0x310 lib/refcount.c:179 Read of size 4 at addr 000000000000002e by task blkid/31392 CPU: 1 PID: 31392 Comm: blkid Not tainted 4.19.0-rc6+ #245 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+0x1c4/0x2b4 lib/dump_stack.c:113 kasan_report_error mm/kasan/report.c:352 [inline] kasan_report.cold.9+0x6d/0x309 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_read+0x11/0x20 mm/kasan/kasan.c:272 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] refcount_sub_and_test_checked+0x9d/0x310 lib/refcount.c:179 refcount_dec_and_test_checked+0x1a/0x20 lib/refcount.c:212 ip_fib_metrics_put include/net/ip.h:428 [inline] fib6_info_destroy_rcu+0x2ef/0x3e0 net/ipv6/ip6_fib.c:204 __rcu_reclaim kernel/rcu/rcu.h:236 [inline] rcu_do_batch kernel/rcu/tree.c:2576 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline] rcu_process_callbacks+0xf23/0x2670 kernel/rcu/tree.c:2864 __do_softirq+0x30b/0xad8 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1cb/0x760 arch/x86/kernel/apic/apic.c:1056 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:864 RIP: 0010:debug_lockdep_rcu_enabled+0x79/0x90 kernel/rcu/update.c:254 Code: 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 1c 8b 05 72 3f 08 08 85 c0 74 07 e8 29 ff ff ff 5d c3 <31> c0 5d c3 e8 fe 5d 5a 00 eb ad e8 f7 5d 5a 00 eb dd 0f 1f 44 00 RSP: 0000:ffff880189007488 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff818b2513 RDX: 0000000000000004 RSI: 0000000000000000 RDI: ffffffff896fe800 RBP: ffff880189007488 R08: ffff88019c3126c0 R09: 0000000000000000 R10: ffffed003b5e4732 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff88019c3126c0 R15: ffff8801d58caddf rcu_read_unlock include/linux/rcupdate.h:679 [inline] is_bpf_text_address+0x84/0x170 kernel/bpf/core.c:545 kernel_text_address+0x79/0xf0 kernel/extable.c:152 __kernel_text_address+0xd/0x40 kernel/extable.c:107 unwind_get_return_address+0x61/0xa0 arch/x86/kernel/unwind_frame.c:18 __save_stack_trace+0x8d/0xf0 arch/x86/kernel/stacktrace.c:45 save_stack_trace+0x1a/0x20 arch/x86/kernel/stacktrace.c:60 save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554 anon_vma_chain_alloc mm/rmap.c:129 [inline] __anon_vma_prepare+0xc6/0x6c0 mm/rmap.c:183 anon_vma_prepare include/linux/rmap.h:153 [inline] do_anonymous_page mm/memory.c:3170 [inline] handle_pte_fault mm/memory.c:3981 [inline] __handle_mm_fault+0x40e2/0x53e0 mm/memory.c:4107 handle_mm_fault+0x54f/0xc70 mm/memory.c:4144 __do_page_fault+0x67d/0xed0 arch/x86/mm/fault.c:1395 do_page_fault+0xf2/0x7e0 arch/x86/mm/fault.c:1470 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1161 RIP: 0033:0x7fc57af24c57 Code: 48 83 ec 18 48 8b 07 48 89 3d dd b1 20 00 48 83 c7 08 48 89 3d 82 af 20 00 89 05 5c b1 20 00 48 98 48 8d 54 c7 08 48 83 3a 00 <48> 89 15 d2 c4 20 00 74 0a 48 83 c2 08 48 83 3a 00 75 f6 48 8d 35 RSP: 002b:00007ffc1eddfe60 EFLAGS: 00010202 RAX: 0000000000000005 RBX: 00007ffc1eddff10 RCX: 00007fc57af28c53 RDX: 00007ffc1eddff48 RSI: 00007fc57af124b0 RDI: 00007ffc1eddff18 RBP: 00007fc57af124b0 R08: 0000000000000002 R09: 0000032ca22025fb R10: 000000006fffff6e R11: 000000006ffffeff R12: 00007fc57af10a78 R13: 00007fc57af10000 R14: 00007fc57af10a78 R15: 00007fc57af10380 ==================================================================