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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 udevd/7847

CPU: 0 PID: 7847 Comm: udevd Not tainted 4.19.0-rc6+ #245
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __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
 </IRQ>
RIP: 0010:kasan_kmalloc+0x40/0xe0 mm/kasan/kasan.c:543
Code: 83 ec 10 a9 00 00 20 00 89 4d d4 75 6f 4d 85 ed 74 5b 49 63 44 24 74 4d 8d 7c 15 ff 48 89 d6 4c 89 ef 49 83 cf 07 49 8d 5f 01 <4d> 8d 74 05 ff e8 f6 fd ff ff 49 83 ce 07 48 89 d8 48 b9 00 00 00
RSP: 0018:ffff880195a07c18 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 0000000000001000 RBX: ffff88019a493380 RCX: 00000000006000c0
RDX: 0000000000001000 RSI: 0000000000001000 RDI: ffff88019a492380
RBP: ffff880195a07c50 R08: 0000000000000048 R09: 00000000bc09dee6
R10: 000000005c00217a R11: 0000000000000000 R12: ffff8801da972d80
R13: ffff88019a492380 R14: ffff8801da972d80 R15: ffff88019a49337f
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554
 getname_flags+0xd0/0x5a0 fs/namei.c:140
 getname+0x19/0x20 fs/namei.c:211
 do_sys_open+0x383/0x700 fs/open.c:1057
 __do_sys_open fs/open.c:1081 [inline]
 __se_sys_open fs/open.c:1076 [inline]
 __x64_sys_open+0x7e/0xc0 fs/open.c:1076
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f085c84f120
Code: 48 8b 15 1b 4d 2b 00 f7 d8 64 89 02 83 c8 ff c3 90 90 90 90 90 90 90 90 90 90 83 3d d5 a4 2b 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 5e 8c 01 00 48 89 04 24
RSP: 002b:00007ffd0f7a8008 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00000000011d3ec0 RCX: 00007f085c84f120
RDX: 00000000000001b6 RSI: 0000000000080000 RDI: 00007ffd0f7a80e0
RBP: 00007ffd0f7a8080 R08: 0000000000000008 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000008
R13: 000000000041f57a R14: 00000000011c2250 R15: 000000000000000b
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