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BUG: KMSAN: uninit-value in core_kernel_text kernel/extable.c:77 [inline]
BUG: KMSAN: uninit-value in kernel_text_address+0x248/0x3a0 kernel/extable.c:127
CPU: 1 PID: 5902 Comm: syz-executor4 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
 core_kernel_text kernel/extable.c:77 [inline]
 kernel_text_address+0x248/0x3a0 kernel/extable.c:127
 __kernel_text_address+0x34/0xe0 kernel/extable.c:107
 unwind_get_return_address+0x8c/0x130 arch/x86/kernel/unwind_frame.c:18
 __save_stack_trace+0x45c/0xa80 arch/x86/kernel/stacktrace.c:45
 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 fs/read_write.c:959 [inline]
 do_readv+0x295/0x5f0 fs/read_write.c:992
 SYSC_readv+0x9b/0xb0 fs/read_write.c:1079
 SyS_readv+0x56/0x80 fs/read_write.c:1076
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x455379
RSP: 002b:00007f3614abfc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000013
RAX: ffffffffffffffda RBX: 00007f3614ac06d4 RCX: 0000000000455379
RDX: 0000000000000001 RSI: 000000002066dff0 RDI: 0000000000000013
RBP: 000000000072bf58 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000495 R14: 00000000006f9e98 R15: 0000000000000001

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521
 update_stack_state+0x959/0xa40 arch/x86/kernel/unwind_frame.c:257
 __unwind_start+0x335/0x630 arch/x86/kernel/unwind_frame.c:404
 unwind_start arch/x86/include/asm/unwind.h:54 [inline]
 __save_stack_trace+0x3e1/0xa80 arch/x86/kernel/stacktrace.c:43
 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 fs/read_write.c:959 [inline]
 do_readv+0x295/0x5f0 fs/read_write.c:992
 SYSC_readv+0x9b/0xb0 fs/read_write.c:1079
 SyS_readv+0x56/0x80 fs/read_write.c:1076
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
Local variable description: ----q.i@do_futex
Variable was created at:
 do_futex+0x1d5/0x6ad0 kernel/futex.c:3499
 SYSC_futex+0x3e1/0x810 kernel/futex.c:3587
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