userfaultfd: fix deadlock warning when locking src and dst VMAs
authorLokesh Gidra <lokeshgidra@google.com>
Thu, 21 Mar 2024 23:58:18 +0000 (16:58 -0700)
committerAndrew Morton <akpm@linux-foundation.org>
Tue, 26 Mar 2024 18:07:23 +0000 (11:07 -0700)
commit30af24facf0aed12dec23bdf6eac6a907f88306a
tree35d01113a579cf8f2543cb0e9a6a3a63cd6ac291
parent0a69b6b3a026543bc215ccc866d0aea5579e6ce2
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>
mm/userfaultfd.c