hwrng: core - correct error check of kthread_run call

commit 17fb874dee093139923af8ed36061faa92cc8e79 upstream.

The kthread_run() function can return two different error values
but the hwrng core only checks for -ENOMEM. If the other error
value -EINTR is returned it is assigned to hwrng_fill and later
used on a kthread_stop() call which naturally crashes.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index da8faf7..5643b65 100644 (file)
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -429,7 +429,7 @@ static int hwrng_fillfn(void *unused)
 static void start_khwrngd(void)
 {
        hwrng_fill = kthread_run(hwrng_fillfn, NULL, "hwrng");
-       if (hwrng_fill == ERR_PTR(-ENOMEM)) {
+       if (IS_ERR(hwrng_fill)) {
                pr_err("hwrng_fill thread creation failed");
                hwrng_fill = NULL;
        }