leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

xen/gntdev: fix gntdev_mmap() error exit path

Browse Source 
Commit d3eeb1d77c ("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: d3eeb1d77c ("xen/gntdev: use mmu_interval_notifier_insert")
Cc: stable@vger.kernel.org
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Link: https://lore.kernel.org/r/20210423054038.26696-1-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
This commit is contained in:
Juergen Gross 2021-04-23 07:40:38 +02:00
parent 6efb943b86
commit 970655aa9b
1 changed files with 3 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/xen/gntdev.c
View File

@ -1017,8 +1017,10 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
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);