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BUG: KMSAN: kernel-infoleak in copyout+0x16b/0x1f0 lib/iov_iter.c:144
CPU: 1 PID: 14158 Comm: blkid Not tainted 5.1.0+ #1
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+0x191/0x1f0 lib/dump_stack.c:113
 kmsan_report+0x130/0x2a0 mm/kmsan/kmsan.c:619
 kmsan_internal_check_memory+0x974/0xa80 mm/kmsan/kmsan.c:713
 kmsan_copy_to_user+0xa9/0xb0 mm/kmsan/kmsan_hooks.c:492
 copyout+0x16b/0x1f0 lib/iov_iter.c:144
 copy_page_to_iter_iovec lib/iov_iter.c:216 [inline]
 copy_page_to_iter+0x654/0x1910 lib/iov_iter.c:905
 generic_file_buffered_read mm/filemap.c:2206 [inline]
 generic_file_read_iter+0x2979/0x3e70 mm/filemap.c:2386
 blkdev_read_iter+0x20d/0x270 fs/block_dev.c:1987
 call_read_iter include/linux/fs.h:1860 [inline]
 new_sync_read fs/read_write.c:406 [inline]
 __vfs_read+0x9af/0xbe0 fs/read_write.c:418
 vfs_read+0x359/0x6f0 fs/read_write.c:452
 ksys_read+0x1c5/0x440 fs/read_write.c:579
 __do_sys_read fs/read_write.c:589 [inline]
 __se_sys_read+0x92/0xb0 fs/read_write.c:587
 __x64_sys_read+0x4a/0x70 fs/read_write.c:587
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x7fc5862be310
Code: 73 01 c3 48 8b 0d 28 4b 2b 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 83 3d e5 a2 2b 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 6e 8a 01 00 48 89 04 24
RSP: 002b:00007ffc72534558 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000007c00 RCX: 00007fc5862be310
RDX: 0000000000000400 RSI: 0000000001167438 RDI: 0000000000000003
RBP: 0000000001167410 R08: 0000000000000028 R09: 0000000001680000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000001163030
R13: 0000000000000400 R14: 0000000001163080 R15: 0000000001167428

Uninit was created at:
 kmsan_save_stack_with_flags+0x7a/0x130 mm/kmsan/kmsan.c:205
 kmsan_internal_alloc_meta_for_pages+0x10f/0x500 mm/kmsan/kmsan_hooks.c:99
 kmsan_alloc_page+0x7a/0xf0 mm/kmsan/kmsan_hooks.c:243
 __alloc_pages_nodemask+0x143d/0x5e90 mm/page_alloc.c:4655
 alloc_pages_current+0x6a0/0x9b0 mm/mempolicy.c:2132
 alloc_pages include/linux/gfp.h:511 [inline]
 __page_cache_alloc+0x95/0x320 mm/filemap.c:948
 pagecache_get_page+0x443/0x11f0 mm/filemap.c:1644
 filemap_fault+0x2705/0x2cd0 mm/filemap.c:2595
 __do_fault mm/memory.c:3042 [inline]
 do_read_fault mm/memory.c:3452 [inline]
 do_fault mm/memory.c:3581 [inline]
 handle_pte_fault mm/memory.c:3812 [inline]
 __handle_mm_fault mm/memory.c:3936 [inline]
 handle_mm_fault+0x76fe/0x9fa0 mm/memory.c:3973
 do_user_addr_fault arch/x86/mm/fault.c:1495 [inline]
 __do_page_fault+0xdf9/0x17f0 arch/x86/mm/fault.c:1561
 do_page_fault+0xb1/0x4d0 arch/x86/mm/fault.c:1592
 page_fault+0x3d/0x50 arch/x86/entry/entry_64.S:1156
 copy_user_generic_unrolled+0x86/0xc0 arch/x86/lib/copy_user_64.S:65
 copy_from_user include/linux/uaccess.h:166 [inline]
 copy_msghdr_from_user+0xe8/0xa10 net/socket.c:2141
 ___sys_sendmsg+0x1e3/0x1200 net/socket.c:2205
 __sys_sendmmsg+0x536/0xaf0 net/socket.c:2355
 __do_sys_sendmmsg net/socket.c:2384 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2381
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2381
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Bytes 0-1023 of 1024 are uninitialized
Memory access of size 1024 starts at ffff8881d9f7ec00
Data copied to user address 0000000001167438
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