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Subject[PATCH 5.10 050/103] HID: wacom: Fix memory leakage caused by kfifo_alloc
Date
From: Ping Cheng <pinglinux@gmail.com>

commit 37309f47e2f5674f3e86cb765312ace42cfcedf5 upstream.

As reported by syzbot below, kfifo_alloc'd memory would not be freed
if a non-zero return value is triggered in wacom_probe. This patch
creates and uses devm_kfifo_alloc to allocate and free itself.

BUG: memory leak
unreferenced object 0xffff88810dc44a00 (size 512):
comm "kworker/1:2", pid 3674, jiffies 4294943617 (age 14.100s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000023e1afac>] kmalloc_array include/linux/slab.h:592 [inline]
[<0000000023e1afac>] __kfifo_alloc+0xad/0x100 lib/kfifo.c:43
[<00000000c477f737>] wacom_probe+0x1a1/0x3b0 drivers/hid/wacom_sys.c:2727
[<00000000b3109aca>] hid_device_probe+0x16b/0x210 drivers/hid/hid-core.c:2281
[<00000000aff7c640>] really_probe+0x159/0x480 drivers/base/dd.c:554
[<00000000778d0bc3>] driver_probe_device+0x84/0x100 drivers/base/dd.c:738
[<000000005108dbb5>] __device_attach_driver+0xee/0x110 drivers/base/dd.c:844
[<00000000efb7c59e>] bus_for_each_drv+0xb7/0x100 drivers/base/bus.c:431
[<0000000024ab1590>] __device_attach+0x122/0x250 drivers/base/dd.c:912
[<000000004c7ac048>] bus_probe_device+0xc6/0xe0 drivers/base/bus.c:491
[<00000000b93050a3>] device_add+0x5ac/0xc30 drivers/base/core.c:2936
[<00000000e5b46ea5>] hid_add_device+0x151/0x390 drivers/hid/hid-core.c:2437
[<00000000c6add147>] usbhid_probe+0x412/0x560 drivers/hid/usbhid/hid-core.c:1407
[<00000000c33acdb4>] usb_probe_interface+0x177/0x370 drivers/usb/core/driver.c:396
[<00000000aff7c640>] really_probe+0x159/0x480 drivers/base/dd.c:554
[<00000000778d0bc3>] driver_probe_device+0x84/0x100 drivers/base/dd.c:738
[<000000005108dbb5>] __device_attach_driver+0xee/0x110 drivers/base/dd.c:844

https://syzkaller.appspot.com/bug?extid=5b49c9695968d7250a26

Reported-by: syzbot+5b49c9695968d7250a26@syzkaller.appspotmail.com
Signed-off-by: Ping Cheng <ping.cheng@wacom.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/hid/wacom_sys.c | 35 ++++++++++++++++++++++++++++++++---
1 file changed, 32 insertions(+), 3 deletions(-)

--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -1270,6 +1270,37 @@ static int wacom_devm_sysfs_create_group
group);
}

+static void wacom_devm_kfifo_release(struct device *dev, void *res)
+{
+ struct kfifo_rec_ptr_2 *devres = res;
+
+ kfifo_free(devres);
+}
+
+static int wacom_devm_kfifo_alloc(struct wacom *wacom)
+{
+ struct wacom_wac *wacom_wac = &wacom->wacom_wac;
+ struct kfifo_rec_ptr_2 *pen_fifo = &wacom_wac->pen_fifo;
+ int error;
+
+ pen_fifo = devres_alloc(wacom_devm_kfifo_release,
+ sizeof(struct kfifo_rec_ptr_2),
+ GFP_KERNEL);
+
+ if (!pen_fifo)
+ return -ENOMEM;
+
+ error = kfifo_alloc(pen_fifo, WACOM_PKGLEN_MAX, GFP_KERNEL);
+ if (error) {
+ devres_free(pen_fifo);
+ return error;
+ }
+
+ devres_add(&wacom->hdev->dev, pen_fifo);
+
+ return 0;
+}
+
enum led_brightness wacom_leds_brightness_get(struct wacom_led *led)
{
struct wacom *wacom = led->wacom;
@@ -2724,7 +2755,7 @@ static int wacom_probe(struct hid_device
if (features->check_for_hid_type && features->hid_type != hdev->type)
return -ENODEV;

- error = kfifo_alloc(&wacom_wac->pen_fifo, WACOM_PKGLEN_MAX, GFP_KERNEL);
+ error = wacom_devm_kfifo_alloc(wacom);
if (error)
return error;

@@ -2786,8 +2817,6 @@ static void wacom_remove(struct hid_devi

if (wacom->wacom_wac.features.type != REMOTE)
wacom_release_resources(wacom);
-
- kfifo_free(&wacom_wac->pen_fifo);
}

#ifdef CONFIG_PM

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