This change gives userfaultfd file descriptors a real security
context, allowing policy to act on them.
Signed-off-by: Daniel Colascione <dancol@xxxxxxxxxx>
---
fs/userfaultfd.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 07b0f6e03849..11227b94a5a7 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1020,6 +1020,8 @@ static int resolve_userfault_fork(struct userfaultfd_ctx *ctx,
{
int fd;
+ /* Regular inode here is okay: only CAP_SYS_PTRACE callers
+ * can monitor forks. */
fd = anon_inode_getfd("[userfaultfd]", &userfaultfd_fops, new,
O_RDWR | (new->flags & UFFD_SHARED_FCNTL_FLAGS));
if (fd < 0)
@@ -1972,8 +1974,9 @@ SYSCALL_DEFINE1(userfaultfd, int, flags)
/* prevent the mm struct to be freed */
mmgrab(ctx->mm);
- fd = anon_inode_getfd("[userfaultfd]", &userfaultfd_fops, ctx,
- O_RDWR | (flags & UFFD_SHARED_FCNTL_FLAGS));
+ fd = anon_inode_getfd2("[userfaultfd]", &userfaultfd_fops, ctx,
+ O_RDWR | (flags & UFFD_SHARED_FCNTL_FLAGS),
+ ANON_INODE_SECURE);
if (fd < 0) {
mmdrop(ctx->mm);
kmem_cache_free(userfaultfd_ctx_cachep, ctx);
--
2.25.0.225.g125e21ebc7-goog
