Patch "hwrng: core - Clean up RNG list when last hwrng is unregistered" has been added to the 4.15-stable tree

This is a note to let you know that I've just added the patch titled

hwrng: core - Clean up RNG list when last hwrng is unregistered

to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
hwrng-core-clean-up-rng-list-when-last-hwrng-is-unregistered.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Gary R Hook <[email protected]>
Date: Fri, 15 Dec 2017 13:55:59 -0600
Subject: hwrng: core - Clean up RNG list when last hwrng is unregistered

From: Gary R Hook <[email protected]>

[ Upstream commit 0e4b52942b1c76f89e0dcb829f72e123d0678f54 ]

Commit 142a27f0a731 added support for a "best" RNG, and in doing so introduced a hang from rmmod/modprobe -r when the last RNG on the list was unloaded.

When the hwrng list is depleted, return the global variables to their original state and decrement all references to the object.

---
 drivers/char/hw_random/core.c |    4 ++++
 1 file changed, 4 insertions(+)

@@ -306,6 +306,10 @@ static int enable_best_rng(void)
 		ret = ((new_rng == current_rng) ? 0 : set_current_rng(new_rng));
 		if (!ret)
 			cur_rng_set_by_user = 0;
+	} else {
+		drop_current_rng();
+		cur_rng_set_by_user = 0;
+		ret = 0;
 	}
 
 	return ret;

Patches currently in stable-queue which might be from [email protected] are

queue-4.15/hwrng-core-clean-up-rng-list-when-last-hwrng-is-unregistered.patch