syzbot

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BUG: KMSAN: uninit-value in __handle_mm_fault mm/memory.c:4059 [inline]
BUG: KMSAN: uninit-value in handle_mm_fault+0x14fc/0x7ed0 mm/memory.c:4126
CPU: 1 PID: 7096 Comm: udevd Not tainted 4.17.0+ #22
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+0x188/0x2a0 mm/kmsan/kmsan.c:990
 __msan_warning_32+0x70/0xc0 mm/kmsan/kmsan_instr.c:640
 __handle_mm_fault mm/memory.c:4059 [inline]
 handle_mm_fault+0x14fc/0x7ed0 mm/memory.c:4126
 __do_page_fault+0xa8f/0x1830 arch/x86/mm/fault.c:1400
 do_page_fault+0x98/0xd0 arch/x86/mm/fault.c:1477
 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1169
RIP: 0033:0x40745c
RSP: 002b:00007ffd29a6e3b0 EFLAGS: 00010207
RAX: 0000000000000001 RBX: 0000000001bb5250 RCX: 00007f1fb2bb7943
RDX: 0000000000000004 RSI: 00007ffd29a6e470 RDI: 0000000000000007
RBP: 0000000000625500 R08: 0000000000000001 R09: 00000000000958a0
R10: 000000000000ee41 R11: 0000000000000246 R12: 0000000001bc6620
R13: 00007ffd29a6f4c7 R14: 0000000000000005 R15: 0000000001bb5250

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:256 [inline]
 kmsan_internal_alloc_meta_for_pages+0x146/0x700 mm/kmsan/kmsan.c:702
 kmsan_alloc_page+0x75/0xd0 mm/kmsan/kmsan_hooks.c:250
 __alloc_pages_nodemask+0xf7b/0x5cc0 mm/page_alloc.c:4404
 __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+0x3163/0x50d0 mm/huge_memory.c:1296
 wp_huge_pmd mm/memory.c:3866 [inline]
 __handle_mm_fault mm/memory.c:4079 [inline]
 handle_mm_fault+0x2328/0x7ed0 mm/memory.c:4126
 __do_page_fault+0xa8f/0x1830 arch/x86/mm/fault.c:1400
 do_page_fault+0x98/0xd0 arch/x86/mm/fault.c:1477
 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1169
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