This is a note to let you know that I've just added the patch titled xen/gntdev: fix gntdev_mmap() error exit path to the 5.12-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: xen-gntdev-fix-gntdev_mmap-error-exit-path.patch and it can be found in the queue-5.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 970655aa9b42461f8394e4457307005bdeee14d9 Mon Sep 17 00:00:00 2001 From: Juergen Gross <jgross@xxxxxxxx> Date: Fri, 23 Apr 2021 07:40:38 +0200 Subject: xen/gntdev: fix gntdev_mmap() error exit path MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Juergen Gross <jgross@xxxxxxxx> commit 970655aa9b42461f8394e4457307005bdeee14d9 upstream. Commit d3eeb1d77c5d0af ("xen/gntdev: use mmu_interval_notifier_insert") introduced an error in gntdev_mmap(): in case the call of mmu_interval_notifier_insert_locked() fails the exit path should not call mmu_interval_notifier_remove(), as this might result in NULL dereferences. One reason for failure is e.g. a signal pending for the running process. Fixes: d3eeb1d77c5d0af ("xen/gntdev: use mmu_interval_notifier_insert") Cc: stable@xxxxxxxxxxxxxxx Reported-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx> Tested-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Reviewed-by: Luca Fancellu <luca.fancellu@xxxxxxx> Link: https://lore.kernel.org/r/20210423054038.26696-1-jgross@xxxxxxxx Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/xen/gntdev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -1017,8 +1017,10 @@ static int gntdev_mmap(struct file *flip err = mmu_interval_notifier_insert_locked( &map->notifier, vma->vm_mm, vma->vm_start, vma->vm_end - vma->vm_start, &gntdev_mmu_ops); - if (err) + if (err) { + map->vma = NULL; goto out_unlock_put; + } } mutex_unlock(&priv->lock); Patches currently in stable-queue which might be from jgross@xxxxxxxx are queue-5.12/xen-gntdev-fix-gntdev_mmap-error-exit-path.patch queue-5.12/xen-unpopulated-alloc-fix-error-return-code-in-fill_.patch