diff options
| author | Xin Zhao <xnzhao@google.com> | 2023-01-30 21:29:47 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-03 11:52:22 +0100 |
| commit | 0412fe1deab1789185e9a744c051ca262b3ee6b7 (patch) | |
| tree | f3f605a6ebf17da23fa0f4a5d6e41dd4f376777f /drivers/hid | |
| parent | b7641733a4a18c6142b88098f9839fd67c37dcff (diff) | |
| download | linux-0412fe1deab1789185e9a744c051ca262b3ee6b7.tar.gz | |
HID: core: Fix deadloop in hid_apply_multiplier.
[ Upstream commit ea427a222d8bdf2bc1a8a6da3ebe247f7dced70c ] The initial value of hid->collection[].parent_idx if 0. When Report descriptor doesn't contain "HID Collection", the value remains as 0. In the meanwhile, when the Report descriptor fullfill all following conditions, it will trigger hid_apply_multiplier function call. 1. Usage page is Generic Desktop Ctrls (0x01) 2. Usage is RESOLUTION_MULTIPLIER (0x48) 3. Contain any FEATURE items The while loop in hid_apply_multiplier will search the top-most collection by searching parent_idx == -1. Because all parent_idx is 0. The loop will run forever. There is a Report Descriptor triggerring the deadloop 0x05, 0x01, // Usage Page (Generic Desktop Ctrls) 0x09, 0x48, // Usage (0x48) 0x95, 0x01, // Report Count (1) 0x75, 0x08, // Report Size (8) 0xB1, 0x01, // Feature Signed-off-by: Xin Zhao <xnzhao@google.com> Link: https://lore.kernel.org/r/20230130212947.1315941-1-xnzhao@google.com Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/hid')
| -rw-r--r-- | drivers/hid/hid-core.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 3e1803592bd4..5c72aef3d3dd 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -1202,6 +1202,7 @@ int hid_open_report(struct hid_device *device) __u8 *end; __u8 *next; int ret; + int i; static int (*dispatch_type[])(struct hid_parser *parser, struct hid_item *item) = { hid_parser_main, @@ -1252,6 +1253,8 @@ int hid_open_report(struct hid_device *device) goto err; } device->collection_size = HID_DEFAULT_NUM_COLLECTIONS; + for (i = 0; i < HID_DEFAULT_NUM_COLLECTIONS; i++) + device->collection[i].parent_idx = -1; ret = -EINVAL; while ((next = fetch_item(start, end, &item)) != NULL) { |