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authorRuss Weight <russell.h.weight@intel.com>2022-08-29 10:45:57 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-09-01 17:46:54 +0200
commit8b40c38e37492b5bdf8e95b46b5cca9517a9957a (patch)
treed930d33cb3332530bbaf6aa1549d4661c55c250e
parent9b03e79300100bcd36e77c8ce94ee7f47cd2f528 (diff)
downloadlinux-8b40c38e37492b5bdf8e95b46b5cca9517a9957a.tar.bz2
firmware_loader: Fix use-after-free during unregister
In the following code within firmware_upload_unregister(), the call to device_unregister() could result in the dev_release function freeing the fw_upload_priv structure before it is dereferenced for the call to module_put(). This bug was found by the kernel test robot using CONFIG_KASAN while running the firmware selftests. device_unregister(&fw_sysfs->dev); module_put(fw_upload_priv->module); The problem is fixed by copying fw_upload_priv->module to a local variable for use when calling device_unregister(). Fixes: 97730bbb242c ("firmware_loader: Add firmware-upload support") Cc: stable <stable@kernel.org> Reported-by: kernel test robot <oliver.sang@intel.com> Reviewed-by: Matthew Gerlach <matthew.gerlach@linux.intel.com> Signed-off-by: Russ Weight <russell.h.weight@intel.com> Link: https://lore.kernel.org/r/20220829174557.437047-1-russell.h.weight@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/base/firmware_loader/sysfs_upload.c3
1 files changed, 2 insertions, 1 deletions
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);