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path: root/drivers/base/firmware_loader/main.c
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Diffstat (limited to 'drivers/base/firmware_loader/main.c')
-rw-r--r--drivers/base/firmware_loader/main.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index 94d1789a233e..406a907a4cae 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -735,6 +735,8 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
size_t offset, u32 opt_flags)
{
struct firmware *fw = NULL;
+ struct cred *kern_cred = NULL;
+ const struct cred *old_cred;
bool nondirect = false;
int ret;
@@ -751,6 +753,18 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
if (ret <= 0) /* error or already assigned */
goto out;
+ /*
+ * We are about to try to access the firmware file. Because we may have been
+ * called by a driver when serving an unrelated request from userland, we use
+ * the kernel credentials to read the file.
+ */
+ kern_cred = prepare_kernel_cred(NULL);
+ if (!kern_cred) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ old_cred = override_creds(kern_cred);
+
ret = fw_get_filesystem_firmware(device, fw->priv, "", NULL);
/* Only full reads can support decompression, platform, and sysfs. */
@@ -776,6 +790,9 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
} else
ret = assign_fw(fw, device);
+ revert_creds(old_cred);
+ put_cred(kern_cred);
+
out:
if (ret < 0) {
fw_abort_batch_reqs(fw);