4.4-stable review patch. If anyone has any objections, please let me know.
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From: Alexander Potapenko glider@google.com
[ Upstream commit 9f138fa609c47403374a862a08a41394be53d461 ]
KMSAN reports a use of uninitialized memory in put_cmsg() because msg.msg_flags in recvfrom haven't been initialized properly. The flag values don't affect the result on this path, but it's still a good idea to initialize them explicitly.
Signed-off-by: Alexander Potapenko glider@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/socket.c | 1 + 1 file changed, 1 insertion(+)
--- a/net/socket.c +++ b/net/socket.c @@ -1697,6 +1697,7 @@ SYSCALL_DEFINE6(recvfrom, int, fd, void /* We assume all kernel code knows the size of sockaddr_storage */ msg.msg_namelen = 0; msg.msg_iocb = NULL; + msg.msg_flags = 0; if (sock->file->f_flags & O_NONBLOCK) flags |= MSG_DONTWAIT; err = sock_recvmsg(sock, &msg, iov_iter_count(&msg.msg_iter), flags);