From 22a05462c3d0eee15154faf8d13c49e6295270a5 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Tomasz=20Paku=C5=82a?= Date: Sat, 1 Feb 2025 12:39:02 +0100 Subject: [PATCH] HID: pidff: Fix null pointer dereference in pidff_find_fields MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This function triggered a null pointer dereference if used to search for a report that isn't implemented on the device. This happened both for optional and required reports alike. The same logic was applied to pidff_find_special_field and although pidff_init_fields should return an error earlier if one of the required reports is missing, future modifications could change this logic and resurface this possible null pointer dereference again. LKML bug report: https://lore.kernel.org/all/CAL-gK7f5=R0nrrQdPtaZZr1fd-cdAMbDMuZ_NLA8vM0SX+nGSw@mail.gmail.com Reported-by: Nolan Nicholson Signed-off-by: Tomasz Pakuła Reviewed-by: Michał Kopeć Reviewed-by: Paul Dino Jones Tested-by: Paul Dino Jones Tested-by: Cristóferson Bueno Tested-by: Pablo Cisneros Signed-off-by: Jiri Kosina --- drivers/hid/usbhid/hid-pidff.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/hid/usbhid/hid-pidff.c b/drivers/hid/usbhid/hid-pidff.c index a7d9f9b19668..ac6f940abd90 100644 --- a/drivers/hid/usbhid/hid-pidff.c +++ b/drivers/hid/usbhid/hid-pidff.c @@ -926,6 +926,11 @@ static void pidff_set_autocenter(struct input_dev *dev, u16 magnitude) static int pidff_find_fields(struct pidff_usage *usage, const u8 *table, struct hid_report *report, int count, int strict) { + if (!report) { + pr_debug("pidff_find_fields, null report\n"); + return -1; + } + int i, j, k, found; int return_value = 0; @@ -1050,6 +1055,11 @@ static int pidff_reports_ok(struct pidff_device *pidff) static struct hid_field *pidff_find_special_field(struct hid_report *report, int usage, int enforce_min) { + if (!report) { + pr_debug("pidff_find_special_field, null report\n"); + return NULL; + } + int i; for (i = 0; i < report->maxfield; i++) { -- 2.50.1