5.15-stable review patch. If anyone has any objections, please let me know.
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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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/hid/usbhid/hid-pidff.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
--- a/drivers/hid/usbhid/hid-pidff.c +++ b/drivers/hid/usbhid/hid-pidff.c @@ -772,6 +772,11 @@ static int pidff_find_fields(struct pidf { int i, j, k, found;
+ if (!report) { + pr_debug("pidff_find_fields, null report\n"); + return -1; + } + for (k = 0; k < count; k++) { found = 0; for (i = 0; i < report->maxfield; i++) { @@ -885,6 +890,11 @@ static struct hid_field *pidff_find_spec { int i;
+ if (!report) { + pr_debug("pidff_find_special_field, null report\n"); + return NULL; + } + for (i = 0; i < report->maxfield; i++) { if (report->field[i]->logical == (HID_UP_PID | usage) && report->field[i]->report_count > 0) {