--- /dev/null
+From 5c089fd0c73411f2170ab795c9ffc16718c7d007 Mon Sep 17 00:00:00 2001
+From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
+Date: Tue, 14 May 2019 16:05:45 -0400
+Subject: idr: Fix idr_get_next race with idr_remove
+
+From: Matthew Wilcox (Oracle) <willy@infradead.org>
+
+commit 5c089fd0c73411f2170ab795c9ffc16718c7d007 upstream.
+
+If the entry is deleted from the IDR between the call to
+radix_tree_iter_find() and rcu_dereference_raw(), idr_get_next()
+will return NULL, which will end the iteration prematurely. We should
+instead continue to the next entry in the IDR. This only happens if the
+iteration is protected by the RCU lock. Most IDR users use a spinlock
+or semaphore to exclude simultaneous modifications. It was noticed once
+the PID allocator was converted to use the IDR, as it uses the RCU lock,
+but there may be other users elsewhere in the kernel.
+
+We can't use the normal pattern of calling radix_tree_deref_retry()
+(which catches both a retry entry in a leaf node and a node entry in
+the root) as the IDR supports storing entries which are unaligned,
+which will trigger an infinite loop if they are encountered. Instead,
+we have to explicitly check whether the entry is a retry entry.
+
+Fixes: 0a835c4f090a ("Reimplement IDR and IDA using the radix tree")
+Reported-by: Brendan Gregg <bgregg@netflix.com>
+Tested-by: Brendan Gregg <bgregg@netflix.com>
+Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+
+---
+ lib/idr.c | 18 +++++++++++-
+ tools/testing/radix-tree/idr-test.c | 52 ++++++++++++++++++++++++++++++++++++
+ 2 files changed, 68 insertions(+), 2 deletions(-)
+
+--- a/lib/idr.c
++++ b/lib/idr.c
+@@ -111,13 +111,27 @@ void *idr_get_next(struct idr *idr, int
+ {
+ struct radix_tree_iter iter;
+ void __rcu **slot;
++ void *entry = NULL;
+
+- slot = radix_tree_iter_find(&idr->idr_rt, &iter, *nextid);
++ radix_tree_for_each_slot(slot, &idr->idr_rt, &iter, *nextid) {
++ entry = radix_tree_deref_slot(slot);
++ if (!entry)
++ continue;
++ if (!radix_tree_deref_retry(entry))
++ break;
++ if (slot != (void *)&idr->idr_rt.rnode &&
++ entry != (void *)RADIX_TREE_INTERNAL_NODE)
++ break;
++ slot = radix_tree_iter_retry(&iter);
++ }
+ if (!slot)
+ return NULL;
+
++ if (WARN_ON_ONCE(iter.index > INT_MAX))
++ return NULL;
++
+ *nextid = iter.index;
+- return rcu_dereference_raw(*slot);
++ return entry;
+ }
+ EXPORT_SYMBOL(idr_get_next);
+
+--- a/tools/testing/radix-tree/idr-test.c
++++ b/tools/testing/radix-tree/idr-test.c
+@@ -177,6 +177,57 @@ void idr_get_next_test(void)
+ idr_destroy(&idr);
+ }
+
++static inline void *idr_mk_value(unsigned long v)
++{
++ BUG_ON((long)v < 0);
++ return (void *)((v & 1) | 2 | (v << 1));
++}
++
++DEFINE_IDR(find_idr);
++
++static void *idr_throbber(void *arg)
++{
++ time_t start = time(NULL);
++ int id = *(int *)arg;
++
++ rcu_register_thread();
++ do {
++ idr_alloc(&find_idr, idr_mk_value(id), id, id + 1, GFP_KERNEL);
++ idr_remove(&find_idr, id);
++ } while (time(NULL) < start + 10);
++ rcu_unregister_thread();
++
++ return NULL;
++}
++
++void idr_find_test_1(int anchor_id, int throbber_id)
++{
++ pthread_t throbber;
++ time_t start = time(NULL);
++
++ pthread_create(&throbber, NULL, idr_throbber, &throbber_id);
++
++ BUG_ON(idr_alloc(&find_idr, idr_mk_value(anchor_id), anchor_id,
++ anchor_id + 1, GFP_KERNEL) != anchor_id);
++
++ do {
++ int id = 0;
++ void *entry = idr_get_next(&find_idr, &id);
++ BUG_ON(entry != idr_mk_value(id));
++ } while (time(NULL) < start + 11);
++
++ pthread_join(throbber, NULL);
++
++ idr_remove(&find_idr, anchor_id);
++ BUG_ON(!idr_is_empty(&find_idr));
++}
++
++void idr_find_test(void)
++{
++ idr_find_test_1(100000, 0);
++ idr_find_test_1(0, 100000);
++}
++
+ void idr_checks(void)
+ {
+ unsigned long i;
+@@ -234,6 +285,7 @@ void idr_checks(void)
+ idr_null_test();
+ idr_nowait_test();
+ idr_get_next_test();
++ idr_find_test();
+ }
+
+ /*
--- /dev/null
+From a56dcc6b455830776899ce3686735f1172e12243 Mon Sep 17 00:00:00 2001
+From: Dan Carpenter <dan.carpenter@oracle.com>
+Date: Wed, 13 Nov 2019 21:28:31 +0300
+Subject: net: cdc_ncm: Signedness bug in cdc_ncm_set_dgram_size()
+
+From: Dan Carpenter <dan.carpenter@oracle.com>
+
+commit a56dcc6b455830776899ce3686735f1172e12243 upstream.
+
+This code is supposed to test for negative error codes and partial
+reads, but because sizeof() is size_t (unsigned) type then negative
+error codes are type promoted to high positive values and the condition
+doesn't work as expected.
+
+Fixes: 332f989a3b00 ("CDC-NCM: handle incomplete transfer of MTU")
+Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/net/usb/cdc_ncm.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/net/usb/cdc_ncm.c
++++ b/drivers/net/usb/cdc_ncm.c
+@@ -579,7 +579,7 @@ static void cdc_ncm_set_dgram_size(struc
+ err = usbnet_read_cmd(dev, USB_CDC_GET_MAX_DATAGRAM_SIZE,
+ USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE,
+ 0, iface_no, &max_datagram_size, sizeof(max_datagram_size));
+- if (err < sizeof(max_datagram_size)) {
++ if (err != sizeof(max_datagram_size)) {
+ dev_dbg(&dev->intf->dev, "GET_MAX_DATAGRAM_SIZE failed\n");
+ goto out;
+ }
projects / thirdparty / kernel / stable-queue.git / commitdiff
