Commit bf1867db authored by Dag Moxnes's avatar Dag Moxnes Committed by David S. Miller
Browse files

net/rds: Whitelist rdma_cookie and rx_tstamp for usercopy 

Add the RDMA cookie and RX timestamp to the usercopy whitelist.

After the introduction of hardened usercopy whitelisting
(https://lwn.net/Articles/727322/

), a warning is displayed when the
RDMA cookie or RX timestamp is copied to userspace:

kernel: WARNING: CPU: 3 PID: 5750 at
mm/usercopy.c:81 usercopy_warn+0x8e/0xa6
[...]
kernel: Call Trace:
kernel: __check_heap_object+0xb8/0x11b
kernel: __check_object_size+0xe3/0x1bc
kernel: put_cmsg+0x95/0x115
kernel: rds_recvmsg+0x43d/0x620 [rds]
kernel: sock_recvmsg+0x43/0x4a
kernel: ___sys_recvmsg+0xda/0x1e6
kernel: ? __handle_mm_fault+0xcae/0xf79
kernel: __sys_recvmsg+0x51/0x8a
kernel: SyS_recvmsg+0x12/0x1c
kernel: do_syscall_64+0x79/0x1ae

When the whitelisting feature was introduced, the memory for the RDMA
cookie and RX timestamp in RDS was not added to the whitelist, causing
the warning above.

Signed-off-by: default avatarDag Moxnes <dag.moxnes@oracle.com>
Tested-by: default avatarJenny <jenny.x.xu@oracle.com>
Acked-by: default avatarSantosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 87cade29

net/rds/ib_recv.c

+8 −3
Original line number Diff line number Diff line
@@ -1048,9 +1048,14 @@ int rds_ib_recv_init(void) 
	si_meminfo(&si);

	rds_ib_sysctl_max_recv_allocation = si.totalram / 3 * PAGE_SIZE / RDS_FRAG_SIZE;



	rds_ib_incoming_slab = kmem_cache_create("rds_ib_incoming",

	rds_ib_incoming_slab =

		kmem_cache_create_usercopy("rds_ib_incoming",

					   sizeof(struct rds_ib_incoming),

					0, SLAB_HWCACHE_ALIGN, NULL);

					   0, SLAB_HWCACHE_ALIGN,

					   offsetof(struct rds_ib_incoming,

						    ii_inc.i_usercopy),

					   sizeof(struct rds_inc_usercopy),

					   NULL);

	if (!rds_ib_incoming_slab)

		goto out;

net/rds/rds.h

+7 −2
Original line number Diff line number Diff line
@@ -271,6 +271,12 @@ struct rds_ext_header_rdma_dest { 
#define	RDS_MSG_RX_END		2

#define	RDS_MSG_RX_CMSG		3



/* The following values are whitelisted for usercopy */

struct rds_inc_usercopy {

	rds_rdma_cookie_t	rdma_cookie;

	ktime_t			rx_tstamp;

};



struct rds_incoming {

	refcount_t		i_refcount;

	struct list_head	i_item;
@@ -280,8 +286,7 @@ struct rds_incoming { 
	unsigned long		i_rx_jiffies;

	struct in6_addr		i_saddr;



	rds_rdma_cookie_t	i_rdma_cookie;

	ktime_t			i_rx_tstamp;

	struct rds_inc_usercopy i_usercopy;

	u64			i_rx_lat_trace[RDS_RX_MAX_TRACES];

};

net/rds/recv.c

+12 −10
Original line number Diff line number Diff line
@@ -47,8 +47,8 @@ void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn, 
	INIT_LIST_HEAD(&inc->i_item);

	inc->i_conn = conn;

	inc->i_saddr = *saddr;

	inc->i_rdma_cookie = 0;

	inc->i_rx_tstamp = ktime_set(0, 0);

	inc->i_usercopy.rdma_cookie = 0;

	inc->i_usercopy.rx_tstamp = ktime_set(0, 0);



	memset(inc->i_rx_lat_trace, 0, sizeof(inc->i_rx_lat_trace));

}
@@ -62,8 +62,8 @@ void rds_inc_path_init(struct rds_incoming *inc, struct rds_conn_path *cp, 
	inc->i_conn = cp->cp_conn;

	inc->i_conn_path = cp;

	inc->i_saddr = *saddr;

	inc->i_rdma_cookie = 0;

	inc->i_rx_tstamp = ktime_set(0, 0);

	inc->i_usercopy.rdma_cookie = 0;

	inc->i_usercopy.rx_tstamp = ktime_set(0, 0);

}

EXPORT_SYMBOL_GPL(rds_inc_path_init);
@@ -186,7 +186,7 @@ static void rds_recv_incoming_exthdrs(struct rds_incoming *inc, struct rds_sock 
		case RDS_EXTHDR_RDMA_DEST:

			/* We ignore the size for now. We could stash it

			 * somewhere and use it for error checking. */

			inc->i_rdma_cookie = rds_rdma_make_cookie(

			inc->i_usercopy.rdma_cookie = rds_rdma_make_cookie(

					be32_to_cpu(buffer.rdma_dest.h_rdma_rkey),

					be32_to_cpu(buffer.rdma_dest.h_rdma_offset));
@@ -380,7 +380,7 @@ void rds_recv_incoming(struct rds_connection *conn, struct in6_addr *saddr, 
				      be32_to_cpu(inc->i_hdr.h_len),

				      inc->i_hdr.h_dport);

		if (sock_flag(sk, SOCK_RCVTSTAMP))

			inc->i_rx_tstamp = ktime_get_real();

			inc->i_usercopy.rx_tstamp = ktime_get_real();

		rds_inc_addref(inc);

		inc->i_rx_lat_trace[RDS_MSG_RX_END] = local_clock();

		list_add_tail(&inc->i_item, &rs->rs_recv_queue);
@@ -540,16 +540,18 @@ static int rds_cmsg_recv(struct rds_incoming *inc, struct msghdr *msg, 
{

	int ret = 0;



	if (inc->i_rdma_cookie) {

	if (inc->i_usercopy.rdma_cookie) {

		ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RDMA_DEST,

				sizeof(inc->i_rdma_cookie), &inc->i_rdma_cookie);

				sizeof(inc->i_usercopy.rdma_cookie),

				&inc->i_usercopy.rdma_cookie);

		if (ret)

			goto out;

	}



	if ((inc->i_rx_tstamp != 0) &&

	if ((inc->i_usercopy.rx_tstamp != 0) &&

	    sock_flag(rds_rs_to_sk(rs), SOCK_RCVTSTAMP)) {

		struct __kernel_old_timeval tv = ns_to_kernel_old_timeval(inc->i_rx_tstamp);

		struct __kernel_old_timeval tv =

			ns_to_kernel_old_timeval(inc->i_usercopy.rx_tstamp);



		if (!sock_flag(rds_rs_to_sk(rs), SOCK_TSTAMP_NEW)) {

			ret = put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD,

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