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BUG: KMSAN: uninit-value in update_stack_state+0x673/0xa40 arch/x86/kernel/unwind_frame.c:222
CPU: 1 PID: 5971 Comm: syz-executor0 Not tainted 4.16.0+ #84
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676
 update_stack_state+0x673/0xa40 arch/x86/kernel/unwind_frame.c:222
 unwind_next_frame+0x618/0xe50 arch/x86/kernel/unwind_frame.c:329
 __save_stack_trace+0x6d9/0xa80 arch/x86/kernel/stacktrace.c:44
 save_stack_trace_tsk+0x258/0x2f0 arch/x86/kernel/stacktrace.c:76
 proc_pid_stack+0x26a/0x470 fs/proc/base.c:446
 proc_single_show+0x1af/0x300 fs/proc/base.c:747
 seq_read+0xc7d/0x2260 fs/seq_file.c:237
 do_loop_readv_writev fs/read_write.c:673 [inline]
 do_iter_read+0x880/0xd70 fs/read_write.c:897
 vfs_readv+0x1ec/0x260 fs/read_write.c:959
 kernel_readv fs/splice.c:361 [inline]
 default_file_splice_read+0xa9a/0x1120 fs/splice.c:416
audit: type=1326 audit(1524069253.764:4): auid=4294967295 uid=0 gid=0 ses=4294967295 pid=5908 comm="syz-executor0" exe="/root/syz-executor0" sig=9 arch=c000003e syscall=202 compat=0 ip=0x455329 code=0x0
 do_splice_to fs/splice.c:880 [inline]
 splice_direct_to_actor+0x4c6/0x1040 fs/splice.c:952
 do_splice_direct+0x335/0x540 fs/splice.c:1061
 do_sendfile+0x1067/0x1e40 fs/read_write.c:1413
 SYSC_sendfile64+0x297/0x300 fs/read_write.c:1474
 SyS_sendfile64+0x64/0x90 fs/read_write.c:1460
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x455329
RSP: 002b:00007fa476f50c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fa476f516d4 RCX: 0000000000455329
RDX: 0000000000000000 RSI: 0000000000000013 RDI: 0000000000000013
RBP: 000000000072bf58 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000044 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000004c6 R14: 00000000006fa330 R15: 0000000000000001

Local variable description: ----flags.i.i.i@rcu_all_qs
Variable was created at:
 rcu_all_qs+0x32/0x1f0 kernel/rcu/tree.c:478
 _cond_resched+0x3c/0xd0 kernel/sched/core.c:4935
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