From 60085c3d009b0df252547adb336d1ccca5ce52ec Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Sun, 7 Apr 2013 01:52:00 +0000 Subject: [PATCH] tipc: fix info leaks via msg_name in recv_msg/recv_stream The code in set_orig_addr() does not initialize all of the members of struct sockaddr_tipc when filling the sockaddr info -- namely the union is only partly filled. This will make recv_msg() and recv_stream() -- the only users of this function -- leak kernel stack memory as the msg_name member is a local variable in net/socket.c. Additionally to that both recv_msg() and recv_stream() fail to update the msg_namelen member to 0 while otherwise returning with 0, i.e. "success". This is the case for, e.g., non-blocking sockets. This will lead to a 128 byte kernel stack leak in net/socket.c. Fix the first issue by initializing the memory of the union with memset(0). Fix the second one by setting msg_namelen to 0 early as it will be updated later if we're going to fill the msg_name member. Cc: Jon Maloy Cc: Allan Stephens Signed-off-by: Mathias Krause Signed-off-by: David S. Miller --- net/tipc/socket.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/tipc/socket.c b/net/tipc/socket.c index a9622b6cd916..515ce38e4f4c 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -790,6 +790,7 @@ static void set_orig_addr(struct msghdr *m, struct tipc_msg *msg) if (addr) { addr->family = AF_TIPC; addr->addrtype = TIPC_ADDR_ID; + memset(&addr->addr, 0, sizeof(addr->addr)); addr->addr.id.ref = msg_origport(msg); addr->addr.id.node = msg_orignode(msg); addr->addr.name.domain = 0; /* could leave uninitialized */ @@ -904,6 +905,9 @@ static int recv_msg(struct kiocb *iocb, struct socket *sock, goto exit; } + /* will be updated in set_orig_addr() if needed */ + m->msg_namelen = 0; + timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); restart: @@ -1013,6 +1017,9 @@ static int recv_stream(struct kiocb *iocb, struct socket *sock, goto exit; } + /* will be updated in set_orig_addr() if needed */ + m->msg_namelen = 0; + target = sock_rcvlowat(sk, flags & MSG_WAITALL, buf_len); timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); -- 2.34.1