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| author | Mark Langsdorf <mlangsdo@redhat.com> | 2021-04-27 21:54:33 +0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-04-28 20:17:54 +0300 |
| commit | 1cfd8956437f842836e8a066b40d1ec2fc01f13e (patch) | |
| tree | e843fc6d6d26bd778bbe7529ffc0c3e115628f39 /drivers/acpi | |
| parent | e483bb9a991bdae29a0caa4b3a6d002c968f94aa (diff) | |
| download | linux-1cfd8956437f842836e8a066b40d1ec2fc01f13e.tar.xz | |
ACPI: custom_method: fix a possible memory leak
In cm_write(), if the 'buf' is allocated memory but not fully consumed,
it is possible to reallocate the buffer without freeing it by passing
'*ppos' as 0 on a subsequent call.
Add an explicit kfree() before kzalloc() to prevent the possible memory
leak.
Fixes: 526b4af47f44 ("ACPI: Split out custom_method functionality into an own driver")
Signed-off-by: Mark Langsdorf <mlangsdo@redhat.com>
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/custom_method.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/acpi/custom_method.c b/drivers/acpi/custom_method.c index 8844f895f9be..d39a9b474727 100644 --- a/drivers/acpi/custom_method.c +++ b/drivers/acpi/custom_method.c @@ -42,6 +42,8 @@ static ssize_t cm_write(struct file *file, const char __user *user_buf, sizeof(struct acpi_table_header))) return -EFAULT; uncopied_bytes = max_size = table.length; + /* make sure the buf is not allocated */ + kfree(buf); buf = kzalloc(max_size, GFP_KERNEL); if (!buf) return -ENOMEM; |