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

ubi: Fix race condition between ubi volume creation and udev

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: ubi-fix-race-condition-between-ubi-volume-creation-and-udev.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From a51a0c8d213594bc094cb8e54aad0cb6d7f7b9a6 Mon Sep 17 00:00:00 2001

From: Clay McClure clay@daemons.net Date: Thu, 21 Sep 2017 19:01:34 -0700 Subject: ubi: Fix race condition between ubi volume creation and udev

From: Clay McClure clay@daemons.net

commit a51a0c8d213594bc094cb8e54aad0cb6d7f7b9a6 upstream.

Similar to commit 714fb87e8bc0 ("ubi: Fix race condition between ubi device creation and udev"), we should make the volume active before registering it.

Signed-off-by: Clay McClure clay@daemons.net Signed-off-by: Richard Weinberger richard@nod.at Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/mtd/ubi/vmt.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)

--- a/drivers/mtd/ubi/vmt.c +++ b/drivers/mtd/ubi/vmt.c @@ -270,6 +270,12 @@ int ubi_create_volume(struct ubi_device vol->last_eb_bytes = vol->usable_leb_size; }

+ /* Make volume "available" before it becomes accessible via sysfs */ + spin_lock(&ubi->volumes_lock); + ubi->volumes[vol_id] = vol; + ubi->vol_count += 1; + spin_unlock(&ubi->volumes_lock); + /* Register character device for the volume */ cdev_init(&vol->cdev, &ubi_vol_cdev_operations); vol->cdev.owner = THIS_MODULE; @@ -298,11 +304,6 @@ int ubi_create_volume(struct ubi_device if (err) goto out_sysfs;

- spin_lock(&ubi->volumes_lock); - ubi->volumes[vol_id] = vol; - ubi->vol_count += 1; - spin_unlock(&ubi->volumes_lock); - ubi_volume_notify(ubi, vol, UBI_VOLUME_ADDED); self_check_volumes(ubi); return err; @@ -315,6 +316,10 @@ out_sysfs: */ cdev_device_del(&vol->cdev, &vol->dev); out_mapping: + spin_lock(&ubi->volumes_lock); + ubi->volumes[vol_id] = NULL; + ubi->vol_count -= 1; + spin_unlock(&ubi->volumes_lock); ubi_eba_destroy_table(eba_tbl); out_acc: spin_lock(&ubi->volumes_lock);

Patches currently in stable-queue which might be from clay@daemons.net are

queue-4.14/ubi-fix-race-condition-between-ubi-volume-creation-and-udev.patch