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| author | Mike Rapoport <rppt@linux.vnet.ibm.com> | 2018-08-03 00:36:09 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-03 01:03:40 +0200 |
| commit | 31e810aa1033a7db50a2746cd34a2432237f6420 (patch) | |
| tree | 54907b7acfdd32910f2ea58912a4b78bbaabaad5 /fs/sync.c | |
| parent | ipc/shm.c add ->pagesize function to shm_vm_ops (diff) | |
| download | linux-31e810aa1033a7db50a2746cd34a2432237f6420.tar.xz linux-31e810aa1033a7db50a2746cd34a2432237f6420.zip | |
userfaultfd: remove uffd flags from vma->vm_flags if UFFD_EVENT_FORK fails
The fix in commit 0cbb4b4f4c44 ("userfaultfd: clear the
vma->vm_userfaultfd_ctx if UFFD_EVENT_FORK fails") cleared the
vma->vm_userfaultfd_ctx but kept userfaultfd flags in vma->vm_flags
that were copied from the parent process VMA.
As the result, there is an inconsistency between the values of
vma->vm_userfaultfd_ctx.ctx and vma->vm_flags which triggers BUG_ON
in userfaultfd_release().
Clearing the uffd flags from vma->vm_flags in case of UFFD_EVENT_FORK
failure resolves the issue.
Link: http://lkml.kernel.org/r/1532931975-25473-1-git-send-email-rppt@linux.vnet.ibm.com
Fixes: 0cbb4b4f4c44 ("userfaultfd: clear the vma->vm_userfaultfd_ctx if UFFD_EVENT_FORK fails")
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Reported-by: syzbot+121be635a7a35ddb7dcb@syzkaller.appspotmail.com
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/sync.c')
0 files changed, 0 insertions, 0 deletions