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 4.4-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-4.4 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 Cc: stable@vger.kernel.org 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 @@ -265,6 +265,12 @@ 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; @@ -304,11 +310,6 @@ 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; @@ -328,6 +329,10 @@ out_sysfs: out_cdev: cdev_del(&vol->cdev); out_mapping: + spin_lock(&ubi->volumes_lock); + ubi->volumes[vol_id] = NULL; + ubi->vol_count -= 1; + spin_unlock(&ubi->volumes_lock); if (do_free) kfree(vol->eba_tbl); out_acc:
Patches currently in stable-queue which might be from clay@daemons.net are
queue-4.4/ubi-fix-race-condition-between-ubi-volume-creation-and-udev.patch