From 08a8a7cf14595f95d5cbb28ef5c15c56a6255fb4 Mon Sep 17 00:00:00 2001 From: Benjamin Tissoires Date: Fri, 13 Jul 2018 16:13:50 +0200 Subject: [PATCH] HID: core: do not upper bound the collection stack Looks like 4 was sufficient until now. However, the Surface Dial needs a stack of 5 and simply fails at probing. Dynamically add HID_COLLECTION_STACK_SIZE to the size of the stack if we hit the upper bound. Checkpatch complains about bare unsigned, so converting those to 'unsigned int' in struct hid_parser Acked-by: Peter Hutterer Signed-off-by: Benjamin Tissoires Signed-off-by: Jiri Kosina --- drivers/hid/hid-core.c | 17 ++++++++++++++--- include/linux/hid.h | 9 +++++---- 2 files changed, 19 insertions(+), 7 deletions(-) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 3942ee61bd1c..5de6f18c9bf7 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -128,9 +128,19 @@ static int open_collection(struct hid_parser *parser, unsigned type) usage = parser->local.usage[0]; - if (parser->collection_stack_ptr == HID_COLLECTION_STACK_SIZE) { - hid_err(parser->device, "collection stack overflow\n"); - return -EINVAL; + if (parser->collection_stack_ptr == parser->collection_stack_size) { + unsigned int *collection_stack; + unsigned int new_size = parser->collection_stack_size + + HID_COLLECTION_STACK_SIZE; + + collection_stack = krealloc(parser->collection_stack, + new_size * sizeof(unsigned int), + GFP_KERNEL); + if (!collection_stack) + return -ENOMEM; + + parser->collection_stack = collection_stack; + parser->collection_stack_size = new_size; } if (parser->device->maxcollection == parser->device->collection_size) { @@ -840,6 +850,7 @@ static int hid_scan_report(struct hid_device *hid) break; } + kfree(parser->collection_stack); vfree(parser); return 0; } diff --git a/include/linux/hid.h b/include/linux/hid.h index 2e4498d52a2f..aee281522c6d 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -644,12 +644,13 @@ static inline void hid_set_drvdata(struct hid_device *hdev, void *data) struct hid_parser { struct hid_global global; struct hid_global global_stack[HID_GLOBAL_STACK_SIZE]; - unsigned global_stack_ptr; + unsigned int global_stack_ptr; struct hid_local local; - unsigned collection_stack[HID_COLLECTION_STACK_SIZE]; - unsigned collection_stack_ptr; + unsigned int *collection_stack; + unsigned int collection_stack_ptr; + unsigned int collection_stack_size; struct hid_device *device; - unsigned scan_flags; + unsigned int scan_flags; }; struct hid_class_descriptor { -- 2.11.0