RDX: 0000000000000001 RSI: 0000000020006140 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000020006240 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000015
R13: 00000000004c0841 R14: 00000000004cffd0 R15: 0000000000000000
==================================================================
BUG: KMSAN: uninit-value in rcu_cblist_dequeue+0x233/0x270 kernel/rcu/rcu_segcblist.c:55
CPU: 1 PID: 4568 Comm: syz-executor1 Not tainted 4.17.0+ #6
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+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1117
 __msan_warning_32+0x70/0xc0 mm/kmsan/kmsan_instr.c:620
 rcu_cblist_dequeue+0x233/0x270 kernel/rcu/rcu_segcblist.c:55
 rcu_do_batch kernel/rcu/tree.c:2673 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2930 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2897 [inline]
 rcu_process_callbacks+0x19a7/0x2060 kernel/rcu/tree.c:2914
 __do_softirq+0x592/0x979 kernel/softirq.c:285
 invoke_softirq kernel/softirq.c:365 [inline]
 irq_exit+0x202/0x240 kernel/softirq.c:405
 exiting_irq+0xe/0x10 arch/x86/include/asm/apic.h:525
 smp_apic_timer_interrupt+0x64/0x90 arch/x86/kernel/apic/apic.c:1055
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
 </IRQ>
RIP: 0010:lowmem_page_address include/linux/mm.h:1098 [inline]
RIP: 0010:msan_get_shadow_origin_ptr+0x1ef/0x230 mm/kmsan/kmsan_instr.c:285
RSP: 0018:ffff88012e41f800 EFLAGS: 00000a07 ORIG_RAX: ffffffffffffff13
RAX: ffff88012eab59b0 RBX: ffffffff8b58a000 RCX: ffff880000000000
RDX: 00000000000009b0 RSI: aaaaaaaaaaaab000 RDI: ffffea0000000000
RBP: ffff88012e41f830 R08: 0000000000000000 R09: ffff880170804000
R10: ffffffff7fffffff R11: ffffffff813553c0 R12: 000000012eab6000
R13: 0000000007180380 R14: ffffffff8b589000 R15: 00000000000009b0
 __msan_metadata_ptr_for_load_8+0x10/0x20 mm/kmsan/kmsan_instr.c:321
 copy_one_pte mm/memory.c:950 [inline]
 copy_pte_range mm/memory.c:1102 [inline]
 copy_pmd_range mm/memory.c:1153 [inline]
 copy_pud_range mm/memory.c:1187 [inline]
 copy_p4d_range mm/memory.c:1209 [inline]
 copy_page_range+0x1808/0x3f50 mm/memory.c:1271
 dup_mmap kernel/fork.c:512 [inline]
 dup_mm kernel/fork.c:1235 [inline]
 copy_mm kernel/fork.c:1289 [inline]
 copy_process+0x6d9b/0x9be0 kernel/fork.c:1795
 _do_fork+0x353/0xf60 kernel/fork.c:2089
 __do_sys_clone kernel/fork.c:2196 [inline]
 __se_sys_clone kernel/fork.c:2190 [inline]
 __x64_sys_clone+0x15e/0x1b0 kernel/fork.c:2190
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4541da
RSP: 002b:0000000000a3ea70 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000a3ea70 RCX: 00000000004541da
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000a3eab0 R08: 0000000000000001 R09: 0000000000c96940
R10: 0000000000c96c10 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000001380

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:294 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:685
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:464
 rcu_segcblist_enqueue+0x24c/0x2d0 kernel/rcu/rcu_segcblist.c:150
 __call_rcu+0x227/0xef0 kernel/rcu/tree.c:3057
 call_rcu_sched+0x32/0x40 kernel/rcu/tree.c:3097
 file_free fs/file_table.c:55 [inline]
 __fput+0x93c/0xa30 fs/file_table.c:226
 ____fput+0x37/0x40 fs/file_table.c:243
 task_work_run+0x22e/0x2b0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x110e/0x3930 kernel/exit.c:867
 do_group_exit+0x1a0/0x360 kernel/exit.c:970
 __do_sys_exit_group+0x21/0x30 kernel/exit.c:981
 __se_sys_exit_group+0x14/0x20 kernel/exit.c:979
 __x64_sys_exit_group+0x4c/0x50 kernel/exit.c:979
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
Local variable description: ----flags.i.i.i.i.i.i.i@kmem_cache_free
Variable was created at:
 kmem_cache_free+0xec/0x2bc0 mm/slub.c:3020
 __kfree_skb+0x23a/0x280 net/core/skbuff.c:604
==================================================================