Messages in this thread Patch in this message | | | From | Russ Weight <> | Subject | [PATCH v1 1/1] firmware_loader: Fix use-after-free during unregister | Date | Tue, 2 Aug 2022 13:09:42 -0700 |
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In the following code within firmware_upload_unregister(), the call to device_unregister() results in the dev_release function freeing the fw_upload_priv structure before it is dereferenced for the call to module_put():
device_unregister(&fw_sysfs->dev); module_put(fw_upload_priv->module);
This is fixed by copying fw_upload_priv->module to a local variable before calling device_unregister() and then using the local variable for the call to module_put().
Reported-by: kernel test robot <oliver.sang@intel.com> Fixes: 97730bbb242c (firmware_loader: Add firmware-upload support) Signed-off-by: Russ Weight <russell.h.weight@intel.com> --- drivers/base/firmware_loader/sysfs_upload.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/base/firmware_loader/sysfs_upload.c b/drivers/base/firmware_loader/sysfs_upload.c index 87044d52322a..63e15bddd80c 100644 --- a/drivers/base/firmware_loader/sysfs_upload.c +++ b/drivers/base/firmware_loader/sysfs_upload.c @@ -377,6 +377,7 @@ void firmware_upload_unregister(struct fw_upload *fw_upload) { struct fw_sysfs *fw_sysfs = fw_upload->priv; struct fw_upload_priv *fw_upload_priv = fw_sysfs->fw_upload_priv; + struct module *module = fw_upload_priv->module; mutex_lock(&fw_upload_priv->lock); if (fw_upload_priv->progress == FW_UPLOAD_PROG_IDLE) { @@ -392,6 +393,6 @@ void firmware_upload_unregister(struct fw_upload *fw_upload) unregister: device_unregister(&fw_sysfs->dev); - module_put(fw_upload_priv->module); + module_put(module); } EXPORT_SYMBOL_GPL(firmware_upload_unregister); -- 2.25.1
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