[PATCH AUTOSEL 5.10 07/39] rpc: fix NULL dereference on kmalloc failure

[PATCH AUTOSEL 5.10 07/39] rpc: fix NULL dereference on kmalloc failure

[Sasha Levin]

From: "J. Bruce Fields" <bfields@redhat.com>

[ Upstream commit 0ddc942394013f08992fc379ca04cffacbbe3dae ]

I think this is unlikely but possible:

svc_authenticate sets rq_authop and calls svcauth_gss_accept.  The
kmalloc(sizeof(*svcdata), GFP_KERNEL) fails, leaving rq_auth_data NULL,
and returning SVC_DENIED.

This causes svc_process_common to go to err_bad_auth, and eventually
call svc_authorise.  That calls ->release == svcauth_gss_release, which
tries to dereference rq_auth_data.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Link: https://lore.kernel.org/linux-nfs/3F1B347F-B809-478F-A1E9-0BE98E22B0F0@oracle.com/T/#t
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/sunrpc/auth_gss/svcauth_gss.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index bd4678db9d76..6dff64374bfe 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1825,11 +1825,14 @@ static int
 svcauth_gss_release(struct svc_rqst *rqstp)
 {
 	struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
-	struct rpc_gss_wire_cred *gc = &gsd->clcred;
+	struct rpc_gss_wire_cred *gc;
 	struct xdr_buf *resbuf = &rqstp->rq_res;
 	int stat = -EINVAL;
 	struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id);
 
+	if (!gsd)
+		goto out;
+	gc = &gsd->clcred;
 	if (gc->gc_proc != RPC_GSS_PROC_DATA)
 		goto out;
 	/* Release can be called twice, but we only wrap once. */
@@ -1870,10 +1873,10 @@ svcauth_gss_release(struct svc_rqst *rqstp)
 	if (rqstp->rq_cred.cr_group_info)
 		put_group_info(rqstp->rq_cred.cr_group_info);
 	rqstp->rq_cred.cr_group_info = NULL;
-	if (gsd->rsci)
+	if (gsd && gsd->rsci) {
 		cache_put(&gsd->rsci->h, sn->rsc_cache);
-	gsd->rsci = NULL;
-
+		gsd->rsci = NULL;
+	}
 	return stat;
 }
 
-- 
2.30.1

[PATCH AUTOSEL 5.10 22/39] vhost: Fix vhost_vq_reset()

[Sasha Levin]

From: Laurent Vivier <lvivier@redhat.com>

[ Upstream commit beb691e69f4dec7bfe8b81b509848acfd1f0dbf9 ]

vhost_reset_is_le() is vhost_init_is_le(), and in the case of
cross-endian legacy, vhost_init_is_le() depends on vq->user_be.

vq->user_be is set by vhost_disable_cross_endian().

But in vhost_vq_reset(), we have:

    vhost_reset_is_le(vq);
    vhost_disable_cross_endian(vq);

And so user_be is used before being set.

To fix that, reverse the lines order as there is no other dependency
between them.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Link: https://lore.kernel.org/r/20210312140913.788592-1-lvivier@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/vhost/vhost.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index a262e12c6dc2..5ccb0705beae 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -332,8 +332,8 @@ static void vhost_vq_reset(struct vhost_dev *dev,
 	vq->error_ctx = NULL;
 	vq->kick = NULL;
 	vq->log_ctx = NULL;
-	vhost_reset_is_le(vq);
 	vhost_disable_cross_endian(vq);
+	vhost_reset_is_le(vq);
 	vq->busyloop_timeout = 0;
 	vq->umem = NULL;
 	vq->iotlb = NULL;
-- 
2.30.1

[PATCH AUTOSEL 5.10 39/39] io_uring: call req_set_fail_links() on short send[msg]()/recv[msg]() with MSG_WAITALL

[Sasha Levin]

From: Stefan Metzmacher <metze@samba.org>

[ Upstream commit 0031275d119efe16711cd93519b595e6f9b4b330 ]

Without that it's not safe to use them in a linked combination with
others.

Now combinations like IORING_OP_SENDMSG followed by IORING_OP_SPLICE
should be possible.

We already handle short reads and writes for the following opcodes:

- IORING_OP_READV
- IORING_OP_READ_FIXED
- IORING_OP_READ
- IORING_OP_WRITEV
- IORING_OP_WRITE_FIXED
- IORING_OP_WRITE
- IORING_OP_SPLICE
- IORING_OP_TEE

Now we have it for these as well:

- IORING_OP_SENDMSG
- IORING_OP_SEND
- IORING_OP_RECVMSG
- IORING_OP_RECV

For IORING_OP_RECVMSG we also check for the MSG_TRUNC and MSG_CTRUNC
flags in order to call req_set_fail_links().

There might be applications arround depending on the behavior
that even short send[msg]()/recv[msg]() retuns continue an
IOSQE_IO_LINK chain.

It's very unlikely that such applications pass in MSG_WAITALL,
which is only defined in 'man 2 recvmsg', but not in 'man 2 sendmsg'.

It's expected that the low level sock_sendmsg() call just ignores
MSG_WAITALL, as MSG_ZEROCOPY is also ignored without explicitly set
SO_ZEROCOPY.

We also expect the caller to know about the implicit truncation to
MAX_RW_COUNT, which we don't detect.

cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/c4e1a4cc0d905314f4d5dc567e65a7b09621aab3.1615908477.git.metze@samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/io_uring.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 38a394c6260d..f8a47cebeacd 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -4390,6 +4390,7 @@ static int io_sendmsg(struct io_kiocb *req, bool force_nonblock,
 	struct io_async_msghdr iomsg, *kmsg;
 	struct socket *sock;
 	unsigned flags;
+	int min_ret = 0;
 	int ret;
 
 	sock = sock_from_file(req->file, &ret);
@@ -4416,6 +4417,9 @@ static int io_sendmsg(struct io_kiocb *req, bool force_nonblock,
 	else if (force_nonblock)
 		flags |= MSG_DONTWAIT;
 
+	if (flags & MSG_WAITALL)
+		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
+
 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
 	if (force_nonblock && ret == -EAGAIN)
 		return io_setup_async_msg(req, kmsg);
@@ -4425,7 +4429,7 @@ static int io_sendmsg(struct io_kiocb *req, bool force_nonblock,
 	if (kmsg->iov != kmsg->fast_iov)
 		kfree(kmsg->iov);
 	req->flags &= ~REQ_F_NEED_CLEANUP;
-	if (ret < 0)
+	if (ret < min_ret)
 		req_set_fail_links(req);
 	__io_req_complete(req, ret, 0, cs);
 	return 0;
@@ -4439,6 +4443,7 @@ static int io_send(struct io_kiocb *req, bool force_nonblock,
 	struct iovec iov;
 	struct socket *sock;
 	unsigned flags;
+	int min_ret = 0;
 	int ret;
 
 	sock = sock_from_file(req->file, &ret);
@@ -4460,6 +4465,9 @@ static int io_send(struct io_kiocb *req, bool force_nonblock,
 	else if (force_nonblock)
 		flags |= MSG_DONTWAIT;
 
+	if (flags & MSG_WAITALL)
+		min_ret = iov_iter_count(&msg.msg_iter);
+
 	msg.msg_flags = flags;
 	ret = sock_sendmsg(sock, &msg);
 	if (force_nonblock && ret == -EAGAIN)
@@ -4467,7 +4475,7 @@ static int io_send(struct io_kiocb *req, bool force_nonblock,
 	if (ret == -ERESTARTSYS)
 		ret = -EINTR;
 
-	if (ret < 0)
+	if (ret < min_ret)
 		req_set_fail_links(req);
 	__io_req_complete(req, ret, 0, cs);
 	return 0;
@@ -4619,6 +4627,7 @@ static int io_recvmsg(struct io_kiocb *req, bool force_nonblock,
 	struct socket *sock;
 	struct io_buffer *kbuf;
 	unsigned flags;
+	int min_ret = 0;
 	int ret, cflags = 0;
 
 	sock = sock_from_file(req->file, &ret);
@@ -4654,6 +4663,9 @@ static int io_recvmsg(struct io_kiocb *req, bool force_nonblock,
 	else if (force_nonblock)
 		flags |= MSG_DONTWAIT;
 
+	if (flags & MSG_WAITALL)
+		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
+
 	ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.umsg,
 					kmsg->uaddr, flags);
 	if (force_nonblock && ret == -EAGAIN)
@@ -4666,7 +4678,7 @@ static int io_recvmsg(struct io_kiocb *req, bool force_nonblock,
 	if (kmsg->iov != kmsg->fast_iov)
 		kfree(kmsg->iov);
 	req->flags &= ~REQ_F_NEED_CLEANUP;
-	if (ret < 0)
+	if (ret < min_ret || ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))
 		req_set_fail_links(req);
 	__io_req_complete(req, ret, cflags, cs);
 	return 0;
@@ -4682,6 +4694,7 @@ static int io_recv(struct io_kiocb *req, bool force_nonblock,
 	struct socket *sock;
 	struct iovec iov;
 	unsigned flags;
+	int min_ret = 0;
 	int ret, cflags = 0;
 
 	sock = sock_from_file(req->file, &ret);
@@ -4712,6 +4725,9 @@ static int io_recv(struct io_kiocb *req, bool force_nonblock,
 	else if (force_nonblock)
 		flags |= MSG_DONTWAIT;
 
+	if (flags & MSG_WAITALL)
+		min_ret = iov_iter_count(&msg.msg_iter);
+
 	ret = sock_recvmsg(sock, &msg, flags);
 	if (force_nonblock && ret == -EAGAIN)
 		return -EAGAIN;
@@ -4720,7 +4736,7 @@ static int io_recv(struct io_kiocb *req, bool force_nonblock,
 out_free:
 	if (req->flags & REQ_F_BUFFER_SELECTED)
 		cflags = io_put_recv_kbuf(req);
-	if (ret < 0)
+	if (ret < min_ret || ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))
 		req_set_fail_links(req);
 	__io_req_complete(req, ret, cflags, cs);
 	return 0;
-- 
2.30.1