syzbot

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BUG: KMSAN: uninit-value in __rb_insert lib/rbtree.c:131 [inline]
BUG: KMSAN: uninit-value in __rb_insert_augmented+0x2de/0x13f0 lib/rbtree.c:495
CPU: 1 PID: 18343 Comm: udevd Not tainted 4.17.0+ #9
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:1125
 __msan_warning_32+0x70/0xc0 mm/kmsan/kmsan_instr.c:620
 __rb_insert lib/rbtree.c:131 [inline]
 __rb_insert_augmented+0x2de/0x13f0 lib/rbtree.c:495
 rb_insert_augmented_cached include/linux/rbtree_augmented.h:71 [inline]
 __anon_vma_interval_tree_insert mm/interval_tree.c:72 [inline]
 anon_vma_interval_tree_insert+0x4ee/0x600 mm/interval_tree.c:83
 anon_vma_chain_link mm/rmap.c:143 [inline]
 anon_vma_clone+0x5c8/0xbf0 mm/rmap.c:278
 anon_vma_fork+0x106/0xb20 mm/rmap.c:331
 dup_mmap kernel/fork.c:467 [inline]
 dup_mm kernel/fork.c:1235 [inline]
 copy_mm kernel/fork.c:1289 [inline]
 copy_process+0x65df/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: 0033:0x7fc0f8229f46
RSP: 002b:00007fff8c280c90 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fff8c280c90 RCX: 00007fc0f8229f46
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007fff8c280cf0 R08: 00000000000047a7 R09: 00000000000047a7
R10: 00007fc0f8b46a70 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff8c280cb0 R14: 0000000000000005 R15: 0000000000000005

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:282 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:297 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:689
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:464
 rb_set_parent_color include/linux/rbtree_augmented.h:131 [inline]
 ____rb_erase_color lib/rbtree.c:296 [inline]
 __rb_erase_color+0x906/0x1d30 lib/rbtree.c:429
 rb_erase_augmented_cached include/linux/rbtree_augmented.h:289 [inline]
 __anon_vma_interval_tree_remove mm/interval_tree.c:72 [inline]
 anon_vma_interval_tree_remove+0x17ab/0x1ad0 mm/interval_tree.c:89
 unlink_anon_vmas+0x218/0xc20 mm/rmap.c:388
 free_pgtables+0x2ee/0x6b0 mm/memory.c:642
 exit_mmap+0x510/0x980 mm/mmap.c:3106
 __mmput+0x158/0x600 kernel/fork.c:962
 mmput+0xab/0xf0 kernel/fork.c:983
 exit_mm+0x6ed/0x7a0 kernel/exit.c:545
 do_exit+0xc12/0x3930 kernel/exit.c:854
 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

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:282 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:192
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:318
 kmem_cache_alloc+0xa97/0xb70 mm/slub.c:2772
 anon_vma_chain_alloc mm/rmap.c:128 [inline]
 anon_vma_clone+0x15c/0xbf0 mm/rmap.c:268
 anon_vma_fork+0x106/0xb20 mm/rmap.c:331
 dup_mmap kernel/fork.c:467 [inline]
 dup_mm kernel/fork.c:1235 [inline]
 copy_mm kernel/fork.c:1289 [inline]
 copy_process+0x65df/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
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