Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-09-20 23:13:00 +00:00
Code Issues Packages Projects Releases Wiki Activity

ACPI: sysfs: Fix create_pnp_modalias() and create_of_modalias()

Browse Source 
snprintf() does not return negative values on error.

To know if the buffer was too small, the returned value needs to be
compared with the length of the passed buffer. If it is greater or
equal, the output has been truncated, so add checks for the truncation
to create_pnp_modalias() and create_of_modalias(). Also make them
return -ENOMEM in that case, as they already do that elsewhere.

Moreover, the remaining size of the buffer used by snprintf() needs to
be updated after the first write to avoid out-of-bounds access as
already done correctly in create_pnp_modalias(), but not in
create_of_modalias(), so change the latter accordingly.

Fixes: 8765c5ba19 ("ACPI / scan: Rework modalias creation when "compatible" is present")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
[ rjw: Merge two patches into one, combine changelogs, add subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Christophe JAILLET 2023-10-23 20:32:54 +02:00 committed by Rafael J. Wysocki
parent 05d3ef8bba
commit 48cf49d319
1 changed files with 6 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/acpi/device_sysfs.c
View File

@ -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 +212,10 @@ 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;
size -= len;
of_compatible = acpi_dev->data.of_compatible;
if (of_compatible->type == ACPI_TYPE_PACKAGE) {