==================================================================
BUG: KMSAN: uninit-value in crc_t10dif_generic+0x155/0x1b0 crypto/crct10dif_common.c:75
CPU: 1 PID: 5207 Comm: syz-executor7 Not tainted 4.16.0+ #81
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
 crc_t10dif_generic+0x155/0x1b0 crypto/crct10dif_common.c:75
 chksum_update+0xb4/0x140 crypto/crct10dif_generic.c:56
 crypto_shash_update crypto/shash.c:117 [inline]
 shash_ahash_update crypto/shash.c:239 [inline]
 shash_async_update+0x290/0x360 crypto/shash.c:247
 crypto_ahash_update include/crypto/hash.h:522 [inline]
 hash_sendpage+0x904/0xe10 crypto/algif_hash.c:173
 kernel_sendpage net/socket.c:3234 [inline]
 sock_sendpage+0x1de/0x2c0 net/socket.c:855
 pipe_to_sendpage+0x31b/0x430 fs/splice.c:451
 splice_from_pipe_feed fs/splice.c:502 [inline]
 __splice_from_pipe+0x49a/0xf30 fs/splice.c:626
 splice_from_pipe fs/splice.c:661 [inline]
 generic_splice_sendpage+0x1c6/0x2a0 fs/splice.c:832
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x19b/0x200 fs/splice.c:1018
 splice_direct_to_actor+0x764/0x1040 fs/splice.c:973
 do_splice_direct+0x335/0x540 fs/splice.c:1061
 do_sendfile+0x1067/0x1e40 fs/read_write.c:1413
 SYSC_sendfile64+0x1b3/0x300 fs/read_write.c:1468
 SyS_sendfile64+0x64/0x90 fs/read_write.c:1460
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
capability: warning: `syz-executor0' uses 32-bit capabilities (legacy support in use)
RIP: 0033:0x455259
RSP: 002b:00007f12b1071c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f12b10726d4 RCX: 0000000000455259
RDX: 0000000020e64ff8 RSI: 0000000000000015 RDI: 0000000000000014
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000100000001 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000004c6 R14: 00000000006fa330 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_alloc_meta_for_pages+0x161/0x3a0 mm/kmsan/kmsan.c:814
 kmsan_alloc_page+0x82/0xe0 mm/kmsan/kmsan.c:868
 __alloc_pages_nodemask+0xf5b/0x5dc0 mm/page_alloc.c:4283
 alloc_pages_vma+0xcc8/0x1800 mm/mempolicy.c:2019
 shmem_alloc_page mm/shmem.c:1471 [inline]
 shmem_alloc_and_acct_page+0x6d5/0x1000 mm/shmem.c:1496
 shmem_getpage_gfp+0x35db/0x5770 mm/shmem.c:1771
 shmem_getpage mm/shmem.c:131 [inline]
 shmem_fallocate+0xde2/0x1610 mm/shmem.c:2939
 vfs_fallocate+0x9dc/0xde0 fs/open.c:319
 SYSC_fallocate+0x119/0x1d0 fs/open.c:342
 SyS_fallocate+0x64/0x90 fs/open.c:336
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2