================================================================== BUG: KMSAN: kernel-infoleak in copyout+0x16b/0x1f0 lib/iov_iter.c:145 CPU: 1 PID: 11827 Comm: blkid Not tainted 5.2.0-rc4+ #7 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+0x162/0x2d0 mm/kmsan/kmsan.c:611 kmsan_internal_check_memory+0x974/0xa80 mm/kmsan/kmsan.c:705 kmsan_copy_to_user+0xa9/0xb0 mm/kmsan/kmsan_hooks.c:496 copyout+0x16b/0x1f0 lib/iov_iter.c:145 copy_page_to_iter_iovec lib/iov_iter.c:217 [inline] copy_page_to_iter+0x6dc/0x1910 lib/iov_iter.c:906 generic_file_buffered_read mm/filemap.c:2118 [inline] generic_file_read_iter+0x2979/0x3e70 mm/filemap.c:2298 blkdev_read_iter+0x20d/0x270 fs/block_dev.c:1983 call_read_iter include/linux/fs.h:1866 [inline] new_sync_read fs/read_write.c:414 [inline] __vfs_read+0xa67/0xc90 fs/read_write.c:427 vfs_read+0x359/0x6f0 fs/read_write.c:461 ksys_read+0x265/0x430 fs/read_write.c:587 __do_sys_read fs/read_write.c:597 [inline] __se_sys_read+0x92/0xb0 fs/read_write.c:595 __x64_sys_read+0x4a/0x70 fs/read_write.c:595 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x63/0xe7 RIP: 0033:0x7fa5cf9b1310 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:00007ffc12535e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa5cf9b1310 RDX: 0000000000000100 RSI: 0000000001708df8 RDI: 0000000000000003 RBP: 0000000001708dd0 R08: 0000000000000028 R09: 0000000001680000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000001708030 R13: 0000000000000100 R14: 0000000001708080 R15: 0000000001708de8 Uninit was created at: kmsan_save_stack_with_flags+0x37/0x70 mm/kmsan/kmsan.c:201 kmsan_internal_alloc_meta_for_pages+0x123/0x510 mm/kmsan/kmsan_hooks.c:103 kmsan_alloc_page+0x7a/0xf0 mm/kmsan/kmsan_hooks.c:247 __alloc_pages_nodemask+0x144d/0x6020 mm/page_alloc.c:4700 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:955 pagecache_get_page+0x443/0x11f0 mm/filemap.c:1645 grab_cache_page_write_begin+0x100/0x180 mm/filemap.c:3159 block_write_begin+0xdd/0x340 fs/buffer.c:2078 blkdev_write_begin+0xf5/0x110 fs/block_dev.c:639 generic_perform_write+0x424/0x990 mm/filemap.c:3209 __generic_file_write_iter+0x421/0xa30 mm/filemap.c:3338 blkdev_write_iter+0x3ef/0x650 fs/block_dev.c:1963 do_iter_readv_writev+0xa16/0xc30 include/linux/fs.h:1866 do_iter_write+0x304/0xdc0 fs/read_write.c:970 vfs_writev fs/read_write.c:1015 [inline] do_writev+0x437/0x910 fs/read_write.c:1058 __do_sys_writev fs/read_write.c:1131 [inline] __se_sys_writev+0x9b/0xb0 fs/read_write.c:1128 __x64_sys_writev+0x4a/0x70 fs/read_write.c:1128 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x63/0xe7 Bytes 4-255 of 256 are uninitialized Memory access of size 256 starts at ffff8880b571f000 Data copied to user address 0000000001708df8 ==================================================================