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BUG: KMSAN: uninit-value in copyout lib/iov_iter.c:140 [inline]
BUG: KMSAN: uninit-value in copy_page_to_iter_iovec lib/iov_iter.c:212 [inline]
BUG: KMSAN: uninit-value in copy_page_to_iter+0x754/0x1b70 lib/iov_iter.c:716
CPU: 1 PID: 6583 Comm: syz-executor6 Not tainted 4.17.0-rc5+ #103
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+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x149/0x260 mm/kmsan/kmsan.c:1084
 kmsan_internal_check_memory+0x179/0x1e0 mm/kmsan/kmsan.c:1196
 kmsan_copy_to_user+0x75/0x160 mm/kmsan/kmsan.c:1219
 copyout lib/iov_iter.c:140 [inline]
 copy_page_to_iter_iovec lib/iov_iter.c:212 [inline]
 copy_page_to_iter+0x754/0x1b70 lib/iov_iter.c:716
 process_vm_rw_pages mm/process_vm_access.c:53 [inline]
 process_vm_rw_single_vec mm/process_vm_access.c:124 [inline]
 process_vm_rw_core+0xf6a/0x1930 mm/process_vm_access.c:220
 process_vm_rw+0x3d0/0x500 mm/process_vm_access.c:288
 __do_sys_process_vm_readv mm/process_vm_access.c:302 [inline]
 __se_sys_process_vm_readv mm/process_vm_access.c:298 [inline]
 __x64_sys_process_vm_readv+0x1a0/0x200 mm/process_vm_access.c:298
 do_syscall_64+0x152/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x455a09
RSP: 002b:00007f109f030c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000136
RAX: ffffffffffffffda RBX: 00007f109f0316d4 RCX: 0000000000455a09
RDX: 0000000000000007 RSI: 0000000020001ac0 RDI: 00000000000000ff
RBP: 000000000072bea0 R08: 0000000000000008 R09: 0000000000000000
R10: 0000000020002140 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000550 R14: 00000000006fd020 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline]
 kmsan_alloc_meta_for_pages+0x161/0x3a0 mm/kmsan/kmsan.c:815
 kmsan_alloc_page+0x82/0xe0 mm/kmsan/kmsan.c:885
 __alloc_pages_nodemask+0xfc0/0x5dc0 mm/page_alloc.c:4402
 __alloc_pages include/linux/gfp.h:458 [inline]
 __alloc_pages_node include/linux/gfp.h:471 [inline]
 alloc_pages_vma+0x1555/0x17f0 mm/mempolicy.c:2049
 do_huge_pmd_wp_page+0x3123/0x50a0 mm/huge_memory.c:1296
 wp_huge_pmd mm/memory.c:3864 [inline]
 __handle_mm_fault mm/memory.c:4077 [inline]
 handle_mm_fault+0x232d/0x7e90 mm/memory.c:4124
 __do_page_fault+0xec6/0x1a10 arch/x86/mm/fault.c:1400
 do_page_fault+0xd3/0x260 arch/x86/mm/fault.c:1477
 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1160

Bytes 0-189 of 190 are uninitialized
Memory access starts at ffff880132401b40
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