audit: type=1326 audit(1523085325.829:4): auid=4294967295 uid=0 gid=0 ses=4294967295 pid=5082 comm="syz-executor1" exe="/root/syz-executor1" sig=31 arch=c000003e syscall=202 compat=0 ip=0x455259 code=0xffff0000 ================================================================== BUG: KMSAN: uninit-value in copyout lib/iov_iter.c:140 [inline] BUG: KMSAN: uninit-value in _copy_to_iter+0x1bb3/0x28f0 lib/iov_iter.c:571 CPU: 1 PID: 5150 Comm: syz-executor6 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 kmsan_internal_check_memory+0x164/0x1d0 mm/kmsan/kmsan.c:1176 kmsan_copy_to_user+0x69/0x160 mm/kmsan/kmsan.c:1199 copyout lib/iov_iter.c:140 [inline] _copy_to_iter+0x1bb3/0x28f0 lib/iov_iter.c:571 copy_to_iter include/linux/uio.h:106 [inline] skb_copy_datagram_iter+0x443/0xf70 net/core/datagram.c:431 skb_copy_datagram_msg include/linux/skbuff.h:3264 [inline] unix_dgram_recvmsg+0xc3f/0x1940 net/unix/af_unix.c:2143 unix_seqpacket_recvmsg+0x11a/0x180 net/unix/af_unix.c:2074 sock_recvmsg_nosec+0x109/0x140 net/socket.c:803 ___sys_recvmsg+0x3fb/0x810 net/socket.c:2205 __sys_recvmmsg+0x54e/0xdb0 net/socket.c:2313 SYSC_recvmmsg+0x212/0x3e0 net/socket.c:2389 SyS_recvmmsg+0x76/0xa0 net/socket.c:2378 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x455259 RSP: 002b:00007f23f8b9ac68 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f23f8b9b6d4 RCX: 0000000000455259 RDX: 00000000000001b1 RSI: 0000000020000800 RDI: 0000000000000013 RBP: 000000000072bf58 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000495 R14: 00000000006f9e98 R15: 0000000000000001 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_save_stack mm/kmsan/kmsan.c:293 [inline] kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684 kmsan_memcpy_origins+0x11d/0x170 mm/kmsan/kmsan.c:526 __msan_memcpy+0x19f/0x1f0 mm/kmsan/kmsan_instr.c:470 _copy_from_iter+0xefb/0x1d40 lib/iov_iter.c:591 copy_from_iter include/linux/uio.h:115 [inline] skb_copy_datagram_from_iter+0x1ff/0xcc0 net/core/datagram.c:521 unix_dgram_sendmsg+0xdce/0x3610 net/unix/af_unix.c:1695 unix_seqpacket_sendmsg+0x262/0x2d0 net/unix/af_unix.c:2063 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] kernel_sendmsg+0x228/0x2d0 net/socket.c:648 sock_no_sendpage+0x1c8/0x250 net/core/sock.c:2578 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 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_file_read_iter+0x508/0x1180 mm/shmem.c:2456 call_read_iter include/linux/fs.h:1776 [inline] generic_file_splice_read+0x4e8/0x830 fs/splice.c:307 do_splice_to fs/splice.c:880 [inline] splice_direct_to_actor+0x4c6/0x1040 fs/splice.c:952 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 Bytes 0-962 of 963 are uninitialized ==================================================================