[PATCH v1 0/2] Input: evdev/uinput errno alignment

[PATCH v1 0/2] Input: evdev/uinput errno alignment

[Iván Ezequiel Rodriguez]

Hi,

Two small fixes so ioctl failures match what helpers and uapi docs
already document.

Patch 1 propagates the return value of input_ff_effect_from_user()
from EVIOCSFF instead of always mapping failures to -EFAULT (wrong
size becomes -EINVAL).

Patch 2 returns -EINVAL for UI_ABS_SETUP when the axis code is out of
range (was -ERANGE) and rejects ABS_MT_SLOT with a non-zero minimum.

Base: v7.3-rc1

Tested: built bzImage with CONFIG_INPUT_UINPUT=y and CONFIG_INPUT_EVDEV=y;
QEMU initramfs smoke:

  - UI_ABS_SETUP with code > ABS_MAX → EINVAL
  - UI_ABS_SETUP ABS_MT_SLOT with min != 0 → EINVAL
  - EVIOCSFF with wrong size → EINVAL

Thanks,
Iván

Iván Ezequiel Rodriguez (2):
  Input: evdev: propagate EVIOCSFF copy errors correctly
  Input: uinput: align UI_ABS_SETUP validation with uapi docs

 drivers/input/evdev.c       | 5 +++--
 drivers/input/misc/uinput.c | 9 ++++++++-
 2 files changed, 11 insertions(+), 3 deletions(-)

-- 
2.43.0

[PATCH v1 1/2] Input: evdev: propagate EVIOCSFF copy errors correctly

[Iván Ezequiel Rodriguez]

Return the error from input_ff_effect_from_user() instead of always
mapping failures to -EFAULT, so wrong buffer sizes surface as -EINVAL.

Signed-off-by: Iván Ezequiel Rodriguez <ivanrwcm25@gmail.com>
---
 drivers/input/evdev.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 3a718d600006..27bcf4f099be 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -1180,8 +1180,9 @@ static long evdev_do_ioctl(struct file *file, unsigned int cmd,
 		return str_to_user(dev->uniq, size, p);
 
 	case EVIOC_MASK_SIZE(EVIOCSFF):
-		if (input_ff_effect_from_user(p, size, &effect))
-			return -EFAULT;
+		error = input_ff_effect_from_user(p, size, &effect);
+		if (error)
+			return error;
 
 		error = input_ff_upload(dev, &effect, file);
 		if (error)
-- 
2.43.0

[PATCH v1 2/2] Input: uinput: align UI_ABS_SETUP validation with uapi docs

[Iván Ezequiel Rodriguez]

Return -EINVAL for out-of-range axis codes and reject ABS_MT_SLOT
configurations whose minimum is not zero, as documented in uapi.

Signed-off-by: Iván Ezequiel Rodriguez <ivanrwcm25@gmail.com>
---
 drivers/input/misc/uinput.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
index d32fa4b508fc..e05c80182252 100644
--- a/drivers/input/misc/uinput.c
+++ b/drivers/input/misc/uinput.c
@@ -424,6 +424,13 @@ static int uinput_validate_absinfo(struct input_dev *dev, unsigned int code,
 	min = abs->minimum;
 	max = abs->maximum;
 
+	if (code == ABS_MT_SLOT && min != 0) {
+		printk(KERN_DEBUG
+		       "%s: abs[%02x] minimum must be 0\n",
+		       UINPUT_NAME, code);
+		return -EINVAL;
+	}
+
 	if ((min != 0 || max != 0) && max < min) {
 		printk(KERN_DEBUG
 		       "%s: invalid abs[%02x] min:%d max:%d\n",
@@ -524,7 +531,7 @@ static int uinput_abs_setup(struct uinput_device *udev,
 		return -EFAULT;
 
 	if (setup.code > ABS_MAX)
-		return -ERANGE;
+		return -EINVAL;
 
 	dev = udev->dev;
 
-- 
2.43.0

[PATCH v2 0/2] Input: evdev/uinput errno alignment

[Iván Ezequiel Rodriguez]

Two small fixes making evdev and uinput report the error codes their
uapi documentation promises.

Changes since v1:
 - Dropped the ABS_MT_SLOT "minimum must be 0" validation from patch 2.
   It was a userspace regression: uinput_create_device() already calls
   input_mt_init_slots() for devices declaring ABS_MT_SLOT, and
   input_mt_init_slots() overwrites the axis with
   input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0).
   A non-zero minimum is therefore accepted today and silently
   corrected, so rejecting it with -EINVAL would break existing
   callers.
 - Patch 2 is now limited to the -ERANGE to -EINVAL change and its
   commit message was reworded accordingly.
 - Patch 1 is unchanged.

v1: https://lore.kernel.org/linux-input/20260831152156.166514-1-ivanrwcm25@gmail.com/

Iván Ezequiel Rodriguez (2):
  Input: evdev: propagate EVIOCSFF copy errors correctly
  Input: uinput: return -EINVAL for out-of-range UI_ABS_SETUP axis code

 drivers/input/evdev.c       | 5 +++--
 drivers/input/misc/uinput.c | 2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

-- 
2.43.0

[PATCH v2 1/2] Input: evdev: propagate EVIOCSFF copy errors correctly

[Iván Ezequiel Rodriguez]

Return the error from input_ff_effect_from_user() instead of always
mapping failures to -EFAULT, so wrong buffer sizes surface as -EINVAL.

Signed-off-by: Iván Ezequiel Rodriguez <ivanrwcm25@gmail.com>
---
 drivers/input/evdev.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 3a718d600006..27bcf4f099be 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -1180,8 +1180,9 @@ static long evdev_do_ioctl(struct file *file, unsigned int cmd,
 		return str_to_user(dev->uniq, size, p);
 
 	case EVIOC_MASK_SIZE(EVIOCSFF):
-		if (input_ff_effect_from_user(p, size, &effect))
-			return -EFAULT;
+		error = input_ff_effect_from_user(p, size, &effect);
+		if (error)
+			return error;
 
 		error = input_ff_upload(dev, &effect, file);
 		if (error)
-- 
2.43.0

[PATCH v2 2/2] Input: uinput: return -EINVAL for out-of-range UI_ABS_SETUP axis code

[Iván Ezequiel Rodriguez]

uinput_abs_setup() rejects an axis code above ABS_MAX with -ERANGE, but
the UI_ABS_SETUP documentation in include/uapi/linux/uinput.h states the
ioctl may only fail with -EINVAL, -ENOMEM or -EFAULT. An out-of-range
code is exactly the "incorrect values" case described there, and every
other validation failure in this path already returns -EINVAL.

Return -EINVAL so the code matches its documented uapi contract.

Signed-off-by: Iván Ezequiel Rodriguez <ivanrwcm25@gmail.com>
---
 drivers/input/misc/uinput.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
index d32fa4b508fc..7d6266c2bd84 100644
--- a/drivers/input/misc/uinput.c
+++ b/drivers/input/misc/uinput.c
@@ -524,7 +524,7 @@ static int uinput_abs_setup(struct uinput_device *udev,
 		return -EFAULT;
 
 	if (setup.code > ABS_MAX)
-		return -ERANGE;
+		return -EINVAL;
 
 	dev = udev->dev;
 
-- 
2.43.0