diff options
author | Greg Kroah-Hartman | 2019-04-21 23:18:44 +0200 |
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committer | Greg Kroah-Hartman | 2019-04-21 23:18:44 +0200 |
commit | 817de6b85914a3dda72b971c074d4d342965fba0 (patch) | |
tree | df0a4563a04aadb8f8595f72392d66d65797c455 /fs/userfaultfd.c | |
parent | staging: kpc2000: add initial set of Daktronics drivers (diff) | |
parent | Linux 5.1-rc6 (diff) | |
download | kernel-qcow2-linux-817de6b85914a3dda72b971c074d4d342965fba0.tar.gz kernel-qcow2-linux-817de6b85914a3dda72b971c074d4d342965fba0.tar.xz kernel-qcow2-linux-817de6b85914a3dda72b971c074d4d342965fba0.zip |
Merge 5.1-rc6 into staging-next
We want the fixes in here as well as this resolves an iio driver merge
issue.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/userfaultfd.c')
-rw-r--r-- | fs/userfaultfd.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 89800fc7dc9d..f5de1e726356 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -629,6 +629,8 @@ static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx, /* the various vma->vm_userfaultfd_ctx still points to it */ down_write(&mm->mmap_sem); + /* no task can run (and in turn coredump) yet */ + VM_WARN_ON(!mmget_still_valid(mm)); for (vma = mm->mmap; vma; vma = vma->vm_next) if (vma->vm_userfaultfd_ctx.ctx == release_new_ctx) { vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; @@ -883,6 +885,8 @@ static int userfaultfd_release(struct inode *inode, struct file *file) * taking the mmap_sem for writing. */ down_write(&mm->mmap_sem); + if (!mmget_still_valid(mm)) + goto skip_mm; prev = NULL; for (vma = mm->mmap; vma; vma = vma->vm_next) { cond_resched(); @@ -905,6 +909,7 @@ static int userfaultfd_release(struct inode *inode, struct file *file) vma->vm_flags = new_flags; vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; } +skip_mm: up_write(&mm->mmap_sem); mmput(mm); wakeup: @@ -1333,6 +1338,8 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, goto out; down_write(&mm->mmap_sem); + if (!mmget_still_valid(mm)) + goto out_unlock; vma = find_vma_prev(mm, start, &prev); if (!vma) goto out_unlock; @@ -1520,6 +1527,8 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx, goto out; down_write(&mm->mmap_sem); + if (!mmget_still_valid(mm)) + goto out_unlock; vma = find_vma_prev(mm, start, &prev); if (!vma) goto out_unlock; |