diff mbox series

[1/4] ACPI: sysfs: Fix the check for a potential string truncation

Message ID 20001867d5d19c3b3e677f6020750cc232b3325b.1698081019.git.christophe.jaillet@wanadoo.fr
State New
Headers
Series ACPI: sysfs: Fix some issues in create_of_modalias() and create_pnp_modalias() |

Commit Message

Christophe JAILLET Oct. 23, 2023, 6:32 p.m. UTC 
  snprintf() does not return negative values on error.
To know if the buffer was too small, the returned value should be compared
with the length of the passed buffer. If it is bigger or equal, then the
output has been truncated.

Update the test for truncation accordingly.

Also return -ENOMEM in such a case, as already done below in the same
functions.

Fixes: 8765c5ba1949 ("ACPI / scan: Rework modalias creation when "compatible" is present")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/acpi/device_sysfs.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c
index 9d8e90744cb5..4deb36dccb73 100644
--- a/drivers/acpi/device_sysfs.c
+++ b/drivers/acpi/device_sysfs.c
@@ -158,8 +158,8 @@  static int create_pnp_modalias(const struct acpi_device *acpi_dev, char *modalia
 		return 0;
 
 	len = snprintf(modalias, size, "acpi:");
-	if (len <= 0)
-		return len;
+	if (len >= size)
+		return -ENOMEM;
 
 	size -= len;
 
@@ -212,8 +212,8 @@  static int create_of_modalias(const struct acpi_device *acpi_dev, char *modalias
 	len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
 	ACPI_FREE(buf.pointer);
 
-	if (len <= 0)
-		return len;
+	if (len >= size)
+		return -ENOMEM;
 
 	of_compatible = acpi_dev->data.of_compatible;
 	if (of_compatible->type == ACPI_TYPE_PACKAGE) {