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authorJakob Koschel2022-03-08 18:18:10 +0100
committerGreg Kroah-Hartman2022-03-15 18:19:44 +0100
commiteb6db9ccf6fb35f44f905d40ffbd667ddcc0e1cc (patch)
treeeb3eced8180631c126f28c21515092823eb90b40
parent36f4c25ce32ed8a2e6304ebee6246b7f0b3b9a6f (diff)
usb: gadget: legacy: remove using list iterator after loop body as a ptr
If the list does not contain the expected element, the value of list_for_each_entry() iterator will not point to a valid structure. To avoid type confusion in such case, the list iterator scope will be limited to list_for_each_entry() loop. In preparation to limiting scope of a list iterator to the list traversal loop, use a dedicated pointer to point to the found element [1]. Determining if an element was found is then simply checking if the pointer is != NULL instead of using the potentially bogus pointer. Link: https://lore.kernel.org/all/YhdfEIwI4EdtHdym@kroah.com/ Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> Link: https://lore.kernel.org/r/20220308171818.384491-19-jakobkoschel@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/gadget/legacy/hid.c23
1 files changed, 12 insertions, 11 deletions
diff --git a/drivers/usb/gadget/legacy/hid.c b/drivers/usb/gadget/legacy/hid.c
index 3912cc805f3a..1187ee4f316a 100644
--- a/drivers/usb/gadget/legacy/hid.c
+++ b/drivers/usb/gadget/legacy/hid.c
@@ -134,7 +134,7 @@ static int hid_bind(struct usb_composite_dev *cdev)
{
struct usb_gadget *gadget = cdev->gadget;
struct list_head *tmp;
- struct hidg_func_node *n, *m;
+ struct hidg_func_node *n = NULL, *m, *iter_n;
struct f_hid_opts *hid_opts;
int status, funcs = 0;
@@ -144,18 +144,19 @@ static int hid_bind(struct usb_composite_dev *cdev)
if (!funcs)
return -ENODEV;
- list_for_each_entry(n, &hidg_func_list, node) {
- n->fi = usb_get_function_instance("hid");
- if (IS_ERR(n->fi)) {
- status = PTR_ERR(n->fi);
+ list_for_each_entry(iter_n, &hidg_func_list, node) {
+ iter_n->fi = usb_get_function_instance("hid");
+ if (IS_ERR(iter_n->fi)) {
+ status = PTR_ERR(iter_n->fi);
+ n = iter_n;
goto put;
}
- hid_opts = container_of(n->fi, struct f_hid_opts, func_inst);
- hid_opts->subclass = n->func->subclass;
- hid_opts->protocol = n->func->protocol;
- hid_opts->report_length = n->func->report_length;
- hid_opts->report_desc_length = n->func->report_desc_length;
- hid_opts->report_desc = n->func->report_desc;
+ hid_opts = container_of(iter_n->fi, struct f_hid_opts, func_inst);
+ hid_opts->subclass = iter_n->func->subclass;
+ hid_opts->protocol = iter_n->func->protocol;
+ hid_opts->report_length = iter_n->func->report_length;
+ hid_opts->report_desc_length = iter_n->func->report_desc_length;
+ hid_opts->report_desc = iter_n->func->report_desc;
}