Patch "pstore: Shut down worker when unregistering" has been added to the 4.11-stable tree

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

pstore: Shut down worker when unregistering

to the 4.11-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:
pstore-shut-down-worker-when-unregistering.patch
and it can be found in the queue-4.11 subdirectory.

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

From: Kees Cook <[email protected]>
Date: Mon, 6 Mar 2017 12:42:12 -0800
Subject: pstore: Shut down worker when unregistering

From: Kees Cook <[email protected]>

commit 6330d5534786d5315d56d558aa6d20740f97d80a upstream.

When built as a module and running with update_ms >= 0, pstore will Oops during module unload since the work timer is still running. This makes sure the worker is stopped before unloading.

---
 fs/pstore/platform.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

@@ -709,6 +709,7 @@ int pstore_register(struct pstore_info *
 	if (psi->flags & PSTORE_FLAGS_PMSG)
 		pstore_register_pmsg();
 
+	/* Start watching for new records, if desired. */
 	if (pstore_update_ms >= 0) {
 		pstore_timer.expires = jiffies +
 			msecs_to_jiffies(pstore_update_ms);

@@ -731,6 +732,11 @@ EXPORT_SYMBOL_GPL(pstore_register);
 
 void pstore_unregister(struct pstore_info *psi)
 {
+	/* Stop timer and make sure all work has finished. */
+	pstore_update_ms = -1;
+	del_timer_sync(&pstore_timer);
+	flush_work(&pstore_work);
+
 	if (psi->flags & PSTORE_FLAGS_PMSG)
 		pstore_unregister_pmsg();
 	if (psi->flags & PSTORE_FLAGS_FTRACE)

@@ -830,7 +836,9 @@ static void pstore_timefunc(unsigned lon
 		schedule_work(&pstore_work);
 	}
 
-	mod_timer(&pstore_timer, jiffies + msecs_to_jiffies(pstore_update_ms));
+	if (pstore_update_ms >= 0)
+		mod_timer(&pstore_timer,
+			  jiffies + msecs_to_jiffies(pstore_update_ms));
 }
 
 module_param(backend, charp, 0444);

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

queue-4.11/fs-xattr.c-zero-out-memory-copied-to-userspace-in-getxattr.patch queue-4.11/pstore-shut-down-worker-when-unregistering.patch queue-4.11/pstore-fix-flags-to-enable-dumps-on-powerpc.patch queue-4.11/pstore-use-dynamic-spinlock-initializer.patch