sctp: fix copying more bytes than expected in sctp_add_bind_addr
Dmitry reported that sctp_add_bind_addr may read more bytes than
expected in case the parameter is a IPv4 addr supplied by the user
through calls such as sctp_bindx_add(), because it always copies
sizeof(union sctp_addr) while the buffer may be just a struct
sockaddr_in, which is smaller.
This patch then fixes it by limiting the memcpy to the min between the
union size and a (new parameter) provided addr size. Where possible this
parameter still is the size of that union, except for reading from
user-provided buffers, which then it accounts for protocol type.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index e878da0..0e3de0c 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -386,7 +386,8 @@
/* Add the address to the bind address list.
* Use GFP_ATOMIC since BHs will be disabled.
*/
- ret = sctp_add_bind_addr(bp, addr, SCTP_ADDR_SRC, GFP_ATOMIC);
+ ret = sctp_add_bind_addr(bp, addr, af->sockaddr_len,
+ SCTP_ADDR_SRC, GFP_ATOMIC);
/* Copy back into socket for getsockname() use. */
if (!ret) {
@@ -577,6 +578,7 @@
af = sctp_get_af_specific(addr->v4.sin_family);
memcpy(&saveaddr, addr, af->sockaddr_len);
retval = sctp_add_bind_addr(bp, &saveaddr,
+ sizeof(saveaddr),
SCTP_ADDR_NEW, GFP_ATOMIC);
addr_buf += af->sockaddr_len;
}
