From: Tomasz Pakuła forest10pl@gmail.com
[ Upstream commit 22a05462c3d0eee15154faf8d13c49e6295270a5 ]
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+n...
Reported-by: Nolan Nicholson nolananicholson@gmail.com Signed-off-by: Tomasz Pakuła tomasz.pakula.oficjalny@gmail.com Reviewed-by: Michał Kopeć michal@nozomi.space Reviewed-by: Paul Dino Jones paul@spacefreak18.xyz Tested-by: Paul Dino Jones paul@spacefreak18.xyz Tested-by: Cristóferson Bueno cbueno81@gmail.com Tested-by: Pablo Cisneros patchkez@protonmail.com Signed-off-by: Jiri Kosina jkosina@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 a01c1b2ab2f4c..26cb331b646ca 100644 --- a/drivers/hid/usbhid/hid-pidff.c +++ b/drivers/hid/usbhid/hid-pidff.c @@ -770,6 +770,11 @@ 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;
for (k = 0; k < count; k++) { @@ -883,6 +888,11 @@ 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++) {