* [PATCH v2 1/4] HID: pass the buffer size to hid_report_raw_event
2026-04-16 14:48 [PATCH v2 0/4] HID: Proper fix for OOM in hid-core Benjamin Tissoires
@ 2026-04-16 14:48 ` Benjamin Tissoires
2026-04-16 14:48 ` [PATCH v2 2/4] HID: core: introduce hid_safe_input_report() Benjamin Tissoires
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Benjamin Tissoires @ 2026-04-16 14:48 UTC (permalink / raw)
To: Jiri Kosina, Filipe Laíns, Bastien Nocera, Ping Cheng,
Jason Gerecke, Viresh Kumar, Johan Hovold, Alex Elder,
Greg Kroah-Hartman, Lee Jones
Cc: linux-input, linux-kernel, greybus-dev, linux-staging, linux-usb,
Benjamin Tissoires, stable
commit 0a3fe972a7cb ("HID: core: Mitigate potential OOB by removing
bogus memset()") enforced the provided data to be at least the size of
the declared buffer in the report descriptor to prevent a buffer
overflow. However, we can try to be smarter by providing both the buffer
size and the data size, meaning that hid_report_raw_event() can make
better decision whether we should plaining reject the buffer (buffer
overflow attempt) or if we can safely memset it to 0 and pass it to the
rest of the stack.
Fixes: 0a3fe972a7cb ("HID: core: Mitigate potential OOB by removing bogus memset()")
Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
---
drivers/hid/bpf/hid_bpf_dispatch.c | 6 ++++--
drivers/hid/hid-core.c | 42 +++++++++++++++++++++++++-------------
drivers/hid/hid-gfrm.c | 4 ++--
drivers/hid/hid-logitech-hidpp.c | 2 +-
drivers/hid/hid-multitouch.c | 2 +-
drivers/hid/hid-primax.c | 2 +-
drivers/hid/hid-vivaldi-common.c | 2 +-
drivers/hid/wacom_sys.c | 6 +++---
drivers/staging/greybus/hid.c | 2 +-
include/linux/hid.h | 4 ++--
include/linux/hid_bpf.h | 14 ++++++++-----
11 files changed, 53 insertions(+), 33 deletions(-)
diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c
index 50c7b45c59e3..d0130658091b 100644
--- a/drivers/hid/bpf/hid_bpf_dispatch.c
+++ b/drivers/hid/bpf/hid_bpf_dispatch.c
@@ -24,7 +24,8 @@ EXPORT_SYMBOL(hid_ops);
u8 *
dispatch_hid_bpf_device_event(struct hid_device *hdev, enum hid_report_type type, u8 *data,
- u32 *size, int interrupt, u64 source, bool from_bpf)
+ size_t *buf_size, u32 *size, int interrupt, u64 source,
+ bool from_bpf)
{
struct hid_bpf_ctx_kern ctx_kern = {
.ctx = {
@@ -74,6 +75,7 @@ dispatch_hid_bpf_device_event(struct hid_device *hdev, enum hid_report_type type
*size = ret;
}
+ *buf_size = ctx_kern.ctx.allocated_size;
return ctx_kern.data;
}
EXPORT_SYMBOL_GPL(dispatch_hid_bpf_device_event);
@@ -505,7 +507,7 @@ __hid_bpf_input_report(struct hid_bpf_ctx *ctx, enum hid_report_type type, u8 *b
if (ret)
return ret;
- return hid_ops->hid_input_report(ctx->hid, type, buf, size, 0, (u64)(long)ctx, true,
+ return hid_ops->hid_input_report(ctx->hid, type, buf, size, size, 0, (u64)(long)ctx, true,
lock_already_taken);
}
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 61afec5915ec..a806820df7e5 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2033,24 +2033,32 @@ int __hid_request(struct hid_device *hid, struct hid_report *report,
}
EXPORT_SYMBOL_GPL(__hid_request);
-int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
- int interrupt)
+int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *data,
+ size_t bufsize, u32 size, int interrupt)
{
struct hid_report_enum *report_enum = hid->report_enum + type;
struct hid_report *report;
struct hid_driver *hdrv;
int max_buffer_size = HID_MAX_BUFFER_SIZE;
u32 rsize, csize = size;
+ size_t bsize = bufsize;
u8 *cdata = data;
int ret = 0;
report = hid_get_report(report_enum, data);
if (!report)
- goto out;
+ return 0;
+
+ if (unlikely(bsize < csize)) {
+ hid_warn_ratelimited(hid, "Event data for report %d is incorrect (%d vs %ld)\n",
+ report->id, csize, bsize);
+ return -EINVAL;
+ }
if (report_enum->numbered) {
cdata++;
csize--;
+ bsize--;
}
rsize = hid_compute_report_size(report);
@@ -2063,11 +2071,16 @@ int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *
else if (rsize > max_buffer_size)
rsize = max_buffer_size;
+ if (bsize < rsize) {
+ hid_warn_ratelimited(hid, "Event data for report %d was too short (%d vs %ld)\n",
+ report->id, rsize, bsize);
+ return -EINVAL;
+ }
+
if (csize < rsize) {
- hid_warn_ratelimited(hid, "Event data for report %d was too short (%d vs %d)\n",
- report->id, rsize, csize);
- ret = -EINVAL;
- goto out;
+ dbg_hid("report %d is too short, (%d < %d)\n", report->id,
+ csize, rsize);
+ memset(cdata + csize, 0, rsize - csize);
}
if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
@@ -2075,7 +2088,7 @@ int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *
if (hid->claimed & HID_CLAIMED_HIDRAW) {
ret = hidraw_report_event(hid, data, size);
if (ret)
- goto out;
+ return ret;
}
if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
@@ -2087,15 +2100,15 @@ int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *
if (hid->claimed & HID_CLAIMED_INPUT)
hidinput_report_event(hid, report);
-out:
+
return ret;
}
EXPORT_SYMBOL_GPL(hid_report_raw_event);
static int __hid_input_report(struct hid_device *hid, enum hid_report_type type,
- u8 *data, u32 size, int interrupt, u64 source, bool from_bpf,
- bool lock_already_taken)
+ u8 *data, size_t bufsize, u32 size, int interrupt, u64 source,
+ bool from_bpf, bool lock_already_taken)
{
struct hid_report_enum *report_enum;
struct hid_driver *hdrv;
@@ -2120,7 +2133,8 @@ static int __hid_input_report(struct hid_device *hid, enum hid_report_type type,
report_enum = hid->report_enum + type;
hdrv = hid->driver;
- data = dispatch_hid_bpf_device_event(hid, type, data, &size, interrupt, source, from_bpf);
+ data = dispatch_hid_bpf_device_event(hid, type, data, &bufsize, &size, interrupt,
+ source, from_bpf);
if (IS_ERR(data)) {
ret = PTR_ERR(data);
goto unlock;
@@ -2149,7 +2163,7 @@ static int __hid_input_report(struct hid_device *hid, enum hid_report_type type,
goto unlock;
}
- ret = hid_report_raw_event(hid, type, data, size, interrupt);
+ ret = hid_report_raw_event(hid, type, data, bufsize, size, interrupt);
unlock:
if (!lock_already_taken)
@@ -2171,7 +2185,7 @@ static int __hid_input_report(struct hid_device *hid, enum hid_report_type type,
int hid_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
int interrupt)
{
- return __hid_input_report(hid, type, data, size, interrupt, 0,
+ return __hid_input_report(hid, type, data, size, size, interrupt, 0,
false, /* from_bpf */
false /* lock_already_taken */);
}
diff --git a/drivers/hid/hid-gfrm.c b/drivers/hid/hid-gfrm.c
index 699186ff2349..d2a56bf92b41 100644
--- a/drivers/hid/hid-gfrm.c
+++ b/drivers/hid/hid-gfrm.c
@@ -66,7 +66,7 @@ static int gfrm_raw_event(struct hid_device *hdev, struct hid_report *report,
switch (data[1]) {
case GFRM100_SEARCH_KEY_DOWN:
ret = hid_report_raw_event(hdev, HID_INPUT_REPORT, search_key_dn,
- sizeof(search_key_dn), 1);
+ sizeof(search_key_dn), sizeof(search_key_dn), 1);
break;
case GFRM100_SEARCH_KEY_AUDIO_DATA:
@@ -74,7 +74,7 @@ static int gfrm_raw_event(struct hid_device *hdev, struct hid_report *report,
case GFRM100_SEARCH_KEY_UP:
ret = hid_report_raw_event(hdev, HID_INPUT_REPORT, search_key_up,
- sizeof(search_key_up), 1);
+ sizeof(search_key_up), sizeof(search_key_up), 1);
break;
default:
diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index b1330d23bd2d..b3ff9265377b 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -3673,7 +3673,7 @@ static int hidpp10_consumer_keys_raw_event(struct hidpp_device *hidpp,
memcpy(&consumer_report[1], &data[3], 4);
/* We are called from atomic context */
hid_report_raw_event(hidpp->hid_dev, HID_INPUT_REPORT,
- consumer_report, 5, 1);
+ consumer_report, sizeof(consumer_report), 5, 1);
return 1;
}
diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index e82a3c4e5b44..eeab0b6e32cc 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -533,7 +533,7 @@ static void mt_get_feature(struct hid_device *hdev, struct hid_report *report)
}
ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT, buf,
- size, 0);
+ size, size, 0);
if (ret)
dev_warn(&hdev->dev, "failed to report feature\n");
}
diff --git a/drivers/hid/hid-primax.c b/drivers/hid/hid-primax.c
index e44d79dff8de..8db054280afb 100644
--- a/drivers/hid/hid-primax.c
+++ b/drivers/hid/hid-primax.c
@@ -44,7 +44,7 @@ static int px_raw_event(struct hid_device *hid, struct hid_report *report,
data[0] |= (1 << (data[idx] - 0xE0));
data[idx] = 0;
}
- hid_report_raw_event(hid, HID_INPUT_REPORT, data, size, 0);
+ hid_report_raw_event(hid, HID_INPUT_REPORT, data, size, size, 0);
return 1;
default: /* unknown report */
diff --git a/drivers/hid/hid-vivaldi-common.c b/drivers/hid/hid-vivaldi-common.c
index bf734055d4b6..b12bb5cc091a 100644
--- a/drivers/hid/hid-vivaldi-common.c
+++ b/drivers/hid/hid-vivaldi-common.c
@@ -85,7 +85,7 @@ void vivaldi_feature_mapping(struct hid_device *hdev,
}
ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT, report_data,
- report_len, 0);
+ report_len, report_len, 0);
if (ret) {
dev_warn(&hdev->dev, "failed to report feature %d\n",
field->report->id);
diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index 0d1c6d90fe21..a32320b351e3 100644
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -90,7 +90,7 @@ static void wacom_wac_queue_flush(struct hid_device *hdev,
kfree(buf);
continue;
}
- err = hid_report_raw_event(hdev, HID_INPUT_REPORT, buf, size, false);
+ err = hid_report_raw_event(hdev, HID_INPUT_REPORT, buf, size, size, false);
if (err) {
hid_warn(hdev, "%s: unable to flush event due to error %d\n",
__func__, err);
@@ -334,7 +334,7 @@ static void wacom_feature_mapping(struct hid_device *hdev,
data, n, WAC_CMD_RETRIES);
if (ret == n && features->type == HID_GENERIC) {
ret = hid_report_raw_event(hdev,
- HID_FEATURE_REPORT, data, n, 0);
+ HID_FEATURE_REPORT, data, n, n, 0);
} else if (ret == 2 && features->type != HID_GENERIC) {
features->touch_max = data[1];
} else {
@@ -395,7 +395,7 @@ static void wacom_feature_mapping(struct hid_device *hdev,
data, n, WAC_CMD_RETRIES);
if (ret == n) {
ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT,
- data, n, 0);
+ data, n, n, 0);
} else {
hid_warn(hdev, "%s: could not retrieve sensor offsets\n",
__func__);
diff --git a/drivers/staging/greybus/hid.c b/drivers/staging/greybus/hid.c
index 1f58c907c036..37e8605c6767 100644
--- a/drivers/staging/greybus/hid.c
+++ b/drivers/staging/greybus/hid.c
@@ -201,7 +201,7 @@ static void gb_hid_init_report(struct gb_hid *ghid, struct hid_report *report)
* we just need to setup the input fields, so using
* hid_report_raw_event is safe.
*/
- hid_report_raw_event(ghid->hid, report->type, ghid->inbuf, size, 1);
+ hid_report_raw_event(ghid->hid, report->type, ghid->inbuf, ghib->bufsize, size, 1);
}
static void gb_hid_init_reports(struct gb_hid *ghid)
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 442a80d79e89..ac432a2ef415 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -1298,8 +1298,8 @@ static inline u32 hid_report_len(struct hid_report *report)
return DIV_ROUND_UP(report->size, 8) + (report->id > 0);
}
-int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
- int interrupt);
+int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *data,
+ size_t bufsize, u32 size, int interrupt);
/* HID quirks API */
unsigned long hid_lookup_quirk(const struct hid_device *hdev);
diff --git a/include/linux/hid_bpf.h b/include/linux/hid_bpf.h
index a2e47dbcf82c..19fffa4574a4 100644
--- a/include/linux/hid_bpf.h
+++ b/include/linux/hid_bpf.h
@@ -72,8 +72,8 @@ struct hid_ops {
int (*hid_hw_output_report)(struct hid_device *hdev, __u8 *buf, size_t len,
u64 source, bool from_bpf);
int (*hid_input_report)(struct hid_device *hid, enum hid_report_type type,
- u8 *data, u32 size, int interrupt, u64 source, bool from_bpf,
- bool lock_already_taken);
+ u8 *data, size_t bufsize, u32 size, int interrupt, u64 source,
+ bool from_bpf, bool lock_already_taken);
struct module *owner;
const struct bus_type *bus_type;
};
@@ -200,7 +200,8 @@ struct hid_bpf {
#ifdef CONFIG_HID_BPF
u8 *dispatch_hid_bpf_device_event(struct hid_device *hid, enum hid_report_type type, u8 *data,
- u32 *size, int interrupt, u64 source, bool from_bpf);
+ size_t *buf_size, u32 *size, int interrupt, u64 source,
+ bool from_bpf);
int dispatch_hid_bpf_raw_requests(struct hid_device *hdev,
unsigned char reportnum, __u8 *buf,
u32 size, enum hid_report_type rtype,
@@ -215,8 +216,11 @@ int hid_bpf_device_init(struct hid_device *hid);
const u8 *call_hid_bpf_rdesc_fixup(struct hid_device *hdev, const u8 *rdesc, unsigned int *size);
#else /* CONFIG_HID_BPF */
static inline u8 *dispatch_hid_bpf_device_event(struct hid_device *hid, enum hid_report_type type,
- u8 *data, u32 *size, int interrupt,
- u64 source, bool from_bpf) { return data; }
+ u8 *data, size_t *buf_size, u32 *size,
+ int interrupt, u64 source, bool from_bpf)
+{
+ return data;
+}
static inline int dispatch_hid_bpf_raw_requests(struct hid_device *hdev,
unsigned char reportnum, u8 *buf,
u32 size, enum hid_report_type rtype,
--
2.53.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH v2 2/4] HID: core: introduce hid_safe_input_report()
2026-04-16 14:48 [PATCH v2 0/4] HID: Proper fix for OOM in hid-core Benjamin Tissoires
2026-04-16 14:48 ` [PATCH v2 1/4] HID: pass the buffer size to hid_report_raw_event Benjamin Tissoires
@ 2026-04-16 14:48 ` Benjamin Tissoires
2026-04-16 14:48 ` [PATCH v2 3/4] HID: multitouch: use __free(kfree) to clean up temporary buffers Benjamin Tissoires
2026-04-16 14:48 ` [PATCH v2 4/4] HID: wacom: " Benjamin Tissoires
3 siblings, 0 replies; 5+ messages in thread
From: Benjamin Tissoires @ 2026-04-16 14:48 UTC (permalink / raw)
To: Jiri Kosina, Filipe Laíns, Bastien Nocera, Ping Cheng,
Jason Gerecke, Viresh Kumar, Johan Hovold, Alex Elder,
Greg Kroah-Hartman, Lee Jones
Cc: linux-input, linux-kernel, greybus-dev, linux-staging, linux-usb,
Benjamin Tissoires, stable
hid_input_report() is used in too many places to have a commit that
doesn't cross subsystem borders. Instead of changing the API, introduce
a new one when things matters in the transport layers:
- usbhid
- i2chid
This effectively revert to the old behavior for those two transport
layers.
Fixes: 0a3fe972a7cb ("HID: core: Mitigate potential OOB by removing bogus memset()")
Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
---
drivers/hid/hid-core.c | 25 +++++++++++++++++++++++++
drivers/hid/i2c-hid/i2c-hid-core.c | 7 ++++---
drivers/hid/usbhid/hid-core.c | 11 ++++++-----
include/linux/hid.h | 2 ++
4 files changed, 37 insertions(+), 8 deletions(-)
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index a806820df7e5..b3596851c719 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2181,6 +2181,7 @@ static int __hid_input_report(struct hid_device *hid, enum hid_report_type type,
* @interrupt: distinguish between interrupt and control transfers
*
* This is data entry for lower layers.
+ * Legacy, please use hid_safe_input_report() instead.
*/
int hid_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
int interrupt)
@@ -2191,6 +2192,30 @@ int hid_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data
}
EXPORT_SYMBOL_GPL(hid_input_report);
+/**
+ * hid_safe_input_report - report data from lower layer (usb, bt...)
+ *
+ * @hid: hid device
+ * @type: HID report type (HID_*_REPORT)
+ * @data: report contents
+ * @bufsize: allocated size of the data buffer
+ * @size: useful size of data parameter
+ * @interrupt: distinguish between interrupt and control transfers
+ *
+ * This is data entry for lower layers.
+ * Please use this function instead of the non safe version because we provide
+ * here the size of the buffer, allowing hid-core to make smarter decisions
+ * regarding the incoming buffer.
+ */
+int hid_safe_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data,
+ size_t bufsize, u32 size, int interrupt)
+{
+ return __hid_input_report(hid, type, data, bufsize, size, interrupt, 0,
+ false, /* from_bpf */
+ false /* lock_already_taken */);
+}
+EXPORT_SYMBOL_GPL(hid_safe_input_report);
+
bool hid_match_one_id(const struct hid_device *hdev,
const struct hid_device_id *id)
{
diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 5a183af3d5c6..e0a302544cef 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -574,9 +574,10 @@ static void i2c_hid_get_input(struct i2c_hid *ihid)
if (ihid->hid->group != HID_GROUP_RMI)
pm_wakeup_event(&ihid->client->dev, 0);
- hid_input_report(ihid->hid, HID_INPUT_REPORT,
- ihid->inbuf + sizeof(__le16),
- ret_size - sizeof(__le16), 1);
+ hid_safe_input_report(ihid->hid, HID_INPUT_REPORT,
+ ihid->inbuf + sizeof(__le16),
+ ihid->bufsize - sizeof(__le16),
+ ret_size - sizeof(__le16), 1);
}
return;
diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index fbbfc0f60829..5af93b9b1fb5 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -283,9 +283,9 @@ static void hid_irq_in(struct urb *urb)
break;
usbhid_mark_busy(usbhid);
if (!test_bit(HID_RESUME_RUNNING, &usbhid->iofl)) {
- hid_input_report(urb->context, HID_INPUT_REPORT,
- urb->transfer_buffer,
- urb->actual_length, 1);
+ hid_safe_input_report(urb->context, HID_INPUT_REPORT,
+ urb->transfer_buffer, urb->transfer_buffer_length,
+ urb->actual_length, 1);
/*
* autosuspend refused while keys are pressed
* because most keyboards don't wake up when
@@ -482,9 +482,10 @@ static void hid_ctrl(struct urb *urb)
switch (status) {
case 0: /* success */
if (usbhid->ctrl[usbhid->ctrltail].dir == USB_DIR_IN)
- hid_input_report(urb->context,
+ hid_safe_input_report(urb->context,
usbhid->ctrl[usbhid->ctrltail].report->type,
- urb->transfer_buffer, urb->actual_length, 0);
+ urb->transfer_buffer, urb->transfer_buffer_length,
+ urb->actual_length, 0);
break;
case -ESHUTDOWN: /* unplug */
unplug = 1;
diff --git a/include/linux/hid.h b/include/linux/hid.h
index ac432a2ef415..bfb9859f391e 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -1030,6 +1030,8 @@ struct hid_field *hid_find_field(struct hid_device *hdev, unsigned int report_ty
int hid_set_field(struct hid_field *, unsigned, __s32);
int hid_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
int interrupt);
+int hid_safe_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data,
+ size_t bufsize, u32 size, int interrupt);
struct hid_field *hidinput_get_led_field(struct hid_device *hid);
unsigned int hidinput_count_leds(struct hid_device *hid);
__s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code);
--
2.53.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH v2 4/4] HID: wacom: use __free(kfree) to clean up temporary buffers
2026-04-16 14:48 [PATCH v2 0/4] HID: Proper fix for OOM in hid-core Benjamin Tissoires
` (2 preceding siblings ...)
2026-04-16 14:48 ` [PATCH v2 3/4] HID: multitouch: use __free(kfree) to clean up temporary buffers Benjamin Tissoires
@ 2026-04-16 14:48 ` Benjamin Tissoires
3 siblings, 0 replies; 5+ messages in thread
From: Benjamin Tissoires @ 2026-04-16 14:48 UTC (permalink / raw)
To: Jiri Kosina, Filipe Laíns, Bastien Nocera, Ping Cheng,
Jason Gerecke, Viresh Kumar, Johan Hovold, Alex Elder,
Greg Kroah-Hartman, Lee Jones
Cc: linux-input, linux-kernel, greybus-dev, linux-staging, linux-usb,
Benjamin Tissoires
This simplifies error handling and protects against memory leaks.
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
---
drivers/hid/wacom_sys.c | 40 +++++++++++++---------------------------
1 file changed, 13 insertions(+), 27 deletions(-)
diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index a32320b351e3..adb31f54e524 100644
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -70,11 +70,10 @@ static void wacom_wac_queue_flush(struct hid_device *hdev,
{
while (!kfifo_is_empty(fifo)) {
int size = kfifo_peek_len(fifo);
- u8 *buf;
unsigned int count;
int err;
- buf = kzalloc(size, GFP_KERNEL);
+ u8 *buf __free(kfree) = kzalloc(size, GFP_KERNEL);
if (!buf) {
kfifo_skip(fifo);
continue;
@@ -87,7 +86,6 @@ static void wacom_wac_queue_flush(struct hid_device *hdev,
// to flush seems reasonable enough, however.
hid_warn(hdev, "%s: removed fifo entry with unexpected size\n",
__func__);
- kfree(buf);
continue;
}
err = hid_report_raw_event(hdev, HID_INPUT_REPORT, buf, size, size, false);
@@ -95,8 +93,6 @@ static void wacom_wac_queue_flush(struct hid_device *hdev,
hid_warn(hdev, "%s: unable to flush event due to error %d\n",
__func__, err);
}
-
- kfree(buf);
}
}
@@ -311,7 +307,6 @@ static void wacom_feature_mapping(struct hid_device *hdev,
struct wacom_features *features = &wacom->wacom_wac.features;
struct hid_data *hid_data = &wacom->wacom_wac.hid_data;
unsigned int equivalent_usage = wacom_equivalent_usage(usage->hid);
- u8 *data;
int ret;
u32 n;
@@ -325,10 +320,11 @@ static void wacom_feature_mapping(struct hid_device *hdev,
/* leave touch_max as is if predefined */
if (!features->touch_max) {
/* read manually */
- n = hid_report_len(field->report);
- data = hid_alloc_report_buf(field->report, GFP_KERNEL);
+ u8 *data __free(kfree) = hid_alloc_report_buf(field->report, GFP_KERNEL);
+
if (!data)
break;
+ n = hid_report_len(field->report);
data[0] = field->report->id;
ret = wacom_get_report(hdev, HID_FEATURE_REPORT,
data, n, WAC_CMD_RETRIES);
@@ -344,7 +340,6 @@ static void wacom_feature_mapping(struct hid_device *hdev,
"defaulting to %d\n",
features->touch_max);
}
- kfree(data);
}
break;
case HID_DG_INPUTMODE:
@@ -386,10 +381,11 @@ static void wacom_feature_mapping(struct hid_device *hdev,
case WACOM_HID_WD_OFFSETRIGHT:
case WACOM_HID_WD_OFFSETBOTTOM:
/* read manually */
- n = hid_report_len(field->report);
- data = hid_alloc_report_buf(field->report, GFP_KERNEL);
+ u8 *data __free(kfree) = hid_alloc_report_buf(field->report, GFP_KERNEL);
+
if (!data)
break;
+ n = hid_report_len(field->report);
data[0] = field->report->id;
ret = wacom_get_report(hdev, HID_FEATURE_REPORT,
data, n, WAC_CMD_RETRIES);
@@ -400,7 +396,6 @@ static void wacom_feature_mapping(struct hid_device *hdev,
hid_warn(hdev, "%s: could not retrieve sensor offsets\n",
__func__);
}
- kfree(data);
break;
}
}
@@ -581,7 +576,6 @@ static int wacom_hid_set_device_mode(struct hid_device *hdev)
static int wacom_set_device_mode(struct hid_device *hdev,
struct wacom_wac *wacom_wac)
{
- u8 *rep_data;
struct hid_report *r;
struct hid_report_enum *re;
u32 length;
@@ -595,7 +589,7 @@ static int wacom_set_device_mode(struct hid_device *hdev,
if (!r)
return -EINVAL;
- rep_data = hid_alloc_report_buf(r, GFP_KERNEL);
+ u8 *rep_data __free(kfree) = hid_alloc_report_buf(r, GFP_KERNEL);
if (!rep_data)
return -ENOMEM;
@@ -614,8 +608,6 @@ static int wacom_set_device_mode(struct hid_device *hdev,
rep_data[1] != wacom_wac->mode_report &&
limit++ < WAC_MSG_RETRIES);
- kfree(rep_data);
-
return error < 0 ? error : 0;
}
@@ -921,7 +913,6 @@ static int wacom_add_shared_data(struct hid_device *hdev)
static int wacom_led_control(struct wacom *wacom)
{
- unsigned char *buf;
int retval;
unsigned char report_id = WAC_CMD_LED_CONTROL;
int buf_size = 9;
@@ -940,7 +931,8 @@ static int wacom_led_control(struct wacom *wacom)
report_id = WAC_CMD_WL_INTUOSP2;
buf_size = 51;
}
- buf = kzalloc(buf_size, GFP_KERNEL);
+
+ unsigned char *buf __free(kfree) = kzalloc(buf_size, GFP_KERNEL);
if (!buf)
return -ENOMEM;
@@ -996,7 +988,6 @@ static int wacom_led_control(struct wacom *wacom)
retval = wacom_set_report(wacom->hdev, HID_FEATURE_REPORT, buf, buf_size,
WAC_CMD_RETRIES);
- kfree(buf);
return retval;
}
@@ -1004,11 +995,10 @@ static int wacom_led_control(struct wacom *wacom)
static int wacom_led_putimage(struct wacom *wacom, int button_id, u8 xfer_id,
const unsigned len, const void *img)
{
- unsigned char *buf;
int i, retval;
const unsigned chunk_len = len / 4; /* 4 chunks are needed to be sent */
- buf = kzalloc(chunk_len + 3 , GFP_KERNEL);
+ unsigned char *buf __free(kfree) = kzalloc(chunk_len + 3, GFP_KERNEL);
if (!buf)
return -ENOMEM;
@@ -1018,7 +1008,7 @@ static int wacom_led_putimage(struct wacom *wacom, int button_id, u8 xfer_id,
retval = wacom_set_report(wacom->hdev, HID_FEATURE_REPORT, buf, 2,
WAC_CMD_RETRIES);
if (retval < 0)
- goto out;
+ return retval;
buf[0] = xfer_id;
buf[1] = button_id & 0x07;
@@ -1038,8 +1028,6 @@ static int wacom_led_putimage(struct wacom *wacom, int button_id, u8 xfer_id,
wacom_set_report(wacom->hdev, HID_FEATURE_REPORT, buf, 2,
WAC_CMD_RETRIES);
-out:
- kfree(buf);
return retval;
}
@@ -1948,10 +1936,9 @@ static int wacom_remote_create_attr_group(struct wacom *wacom, __u32 serial,
static int wacom_cmd_unpair_remote(struct wacom *wacom, unsigned char selector)
{
const size_t buf_size = 2;
- unsigned char *buf;
int retval;
- buf = kzalloc(buf_size, GFP_KERNEL);
+ unsigned char *buf __free(kfree) = kzalloc(buf_size, GFP_KERNEL);
if (!buf)
return -ENOMEM;
@@ -1960,7 +1947,6 @@ static int wacom_cmd_unpair_remote(struct wacom *wacom, unsigned char selector)
retval = wacom_set_report(wacom->hdev, HID_OUTPUT_REPORT, buf,
buf_size, WAC_CMD_RETRIES);
- kfree(buf);
return retval;
}
--
2.53.0
^ permalink raw reply related [flat|nested] 5+ messages in thread