syzbot

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BUG: KMSAN: uninit-value in _mix_pool_bytes+0x7d2/0x950 drivers/char/random.c:570
CPU: 1 PID: 2708 Comm: hwrng Not tainted 5.10.0-rc1-syzkaller #0
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+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197
 _mix_pool_bytes+0x7d2/0x950 drivers/char/random.c:570
 mix_pool_bytes+0xca/0x220 drivers/char/random.c:599
 add_hwgenerator_randomness+0x4ac/0x500 drivers/char/random.c:2318
 hwrng_fillfn+0x6ae/0x940 drivers/char/hw_random/core.c:452
 kthread+0x51c/0x560 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:104
 kmsan_slab_alloc+0x8d/0xe0 mm/kmsan/kmsan_hooks.c:76
 slab_alloc_node mm/slub.c:2906 [inline]
 slab_alloc mm/slub.c:2915 [inline]
 kmem_cache_alloc_trace+0x7fe/0xfd0 mm/slub.c:2932
 kmalloc include/linux/slab.h:552 [inline]
 hwrng_modinit+0x103/0x2ef drivers/char/hw_random/core.c:621
 do_one_initcall+0x371/0x8e0 init/main.c:1210
 do_initcall_level+0x1e7/0x35a init/main.c:1283
 do_initcalls+0x127/0x1cb init/main.c:1299
 do_basic_setup+0x33/0x36 init/main.c:1319
 kernel_init_freeable+0x238/0x38b init/main.c:1519
 kernel_init+0x1f/0x840 init/main.c:1408
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
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