Messages in this thread Patch in this message | | | Date | Tue, 31 Oct 2017 09:14:45 -0700 | From | Kees Cook <> | Subject | [PATCH] net: recvmsg: Unconditionally zero struct sockaddr_storage |
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Some protocols do not correctly wipe the contents of the on-stack struct sockaddr_storage sent down into recvmsg() (e.g. SCTP), and leak kernel stack contents to userspace. This wipes it unconditionally before per-protocol handlers run.
Note that leaks like this are mitigated by building with CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL=y
Reported-by: Alexander Potapenko <glider@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> --- net/socket.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/net/socket.c b/net/socket.c index c729625eb5d3..34183f4fbdf8 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2188,6 +2188,7 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg, struct sockaddr __user *uaddr; int __user *uaddr_len = COMPAT_NAMELEN(msg); + memset(&addr, 0, sizeof(addr)); msg_sys->msg_name = &addr; if (MSG_CMSG_COMPAT & flags) -- 2.7.4
-- Kees Cook Pixel Security
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