diff options
| author | Lokesh Gidra <lokeshgidra@google.com> | 2024-03-21 16:58:18 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-03-26 11:07:23 -0700 |
| commit | 30af24facf0aed12dec23bdf6eac6a907f88306a (patch) | |
| tree | 35d01113a579cf8f2543cb0e9a6a3a63cd6ac291 | |
| parent | 0a69b6b3a026543bc215ccc866d0aea5579e6ce2 (diff) | |
| download | linux-30af24facf0aed12dec23bdf6eac6a907f88306a.tar.gz | |
userfaultfd: fix deadlock warning when locking src and dst VMAs
Use down_read_nested() to avoid the warning.
Link: https://lkml.kernel.org/r/20240321235818.125118-1-lokeshgidra@google.com
Fixes: 867a43a34ff8 ("userfaultfd: use per-vma locks in userfaultfd operations")
Reported-by: syzbot+49056626fe41e01f2ba7@syzkaller.appspotmail.com
Signed-off-by: Lokesh Gidra <lokeshgidra@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Jann Horn <jannh@google.com> [Bug #2]
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Nicolas Geoffray <ngeoffray@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | mm/userfaultfd.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 712160cd41eca..3c3539c573e7f 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -1444,7 +1444,8 @@ static int uffd_move_lock(struct mm_struct *mm, */ down_read(&(*dst_vmap)->vm_lock->lock); if (*dst_vmap != *src_vmap) - down_read(&(*src_vmap)->vm_lock->lock); + down_read_nested(&(*src_vmap)->vm_lock->lock, + SINGLE_DEPTH_NESTING); } mmap_read_unlock(mm); return err; |