netlink: 17 bytes leftover after parsing attributes in process `syz-executor2'. ================================================================== 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 syz-executor2/11366 CPU: 0 PID: 11366 Comm: syz-executor2 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:__tlb_remove_page_size+0x114/0x500 mm/memory.c:304 Code: 02 84 c0 74 08 3c 03 0f 8e 2a 03 00 00 48 ba 00 00 00 00 00 fc ff df 8b 43 08 48 8d 7c c3 10 44 8d 68 01 48 89 f9 48 c1 e9 03 <44> 89 6b 08 80 3c 11 00 0f 85 1d 03 00 00 48 8d 7b 0c 4c 89 7c c3 RSP: 0018:ffff88019c18ec08 EFLAGS: 00000a02 ORIG_RAX: ffffffffffffff13 RAX: 00000000000001cc RBX: ffff8801be9e2000 RCX: 1ffff10037d3c5ce RDX: dffffc0000000000 RSI: ffffffff81b1ac8d RDI: ffff8801be9e2e70 RBP: ffff88019c18ec38 R08: ffff88019a7ac140 R09: fffff94000de7f5e R10: fffff94000de7f5e R11: ffffea0006f3faf3 R12: ffff88019c18f140 R13: 00000000000001cd R14: ffff88019c18f168 R15: ffffea0006f3fac0 __tlb_remove_page include/asm-generic/tlb.h:161 [inline] zap_pte_range mm/memory.c:1341 [inline] zap_pmd_range mm/memory.c:1440 [inline] zap_pud_range mm/memory.c:1469 [inline] zap_p4d_range mm/memory.c:1490 [inline] unmap_page_range+0xf4a/0x2030 mm/memory.c:1511 unmap_single_vma+0x19b/0x310 mm/memory.c:1556 unmap_vmas+0x125/0x200 mm/memory.c:1586 exit_mmap+0x2be/0x590 mm/mmap.c:3093 __mmput kernel/fork.c:1001 [inline] mmput+0x247/0x610 kernel/fork.c:1022 exit_mm kernel/exit.c:545 [inline] do_exit+0xe6f/0x2610 kernel/exit.c:854 do_group_exit+0x177/0x440 kernel/exit.c:970 get_signal+0x8b0/0x1980 kernel/signal.c:2513 do_signal+0x9c/0x21e0 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x2e5/0x380 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f26d87edcf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 000000000072bf08 RCX: 0000000000457579 RDX: 00000000004c445b RSI: 0000000000000081 RDI: 000000000072bf0c RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000246 R12: 000000000072bf0c R13: 00007ffc453c5e1f R14: 00007f26d87ee9c0 R15: 0000000000000000 ==================================================================