@@ -2111,6 +2111,20 @@ int do_epoll_ctl(int epfd, int op, int fd, struct epoll_event *epds,
if (!f.file)
goto error_return;
+ /*
+ * We have to check that the file structure underneath the file
+ * descriptor the user passed to us _is_ an eventpoll file.
+ */
+ error = -EINVAL;
+ if (!is_file_epoll(f.file))
+ goto error_fput;
+
+ /*
+ * At this point it is safe to assume that the "private_data" contains
+ * our own data structure.
+ */
+ ep = f.file->private_data;
+
/* Get the "struct file *" for the target file */
tf = fdget(fd);
if (!tf.file)
@@ -2126,12 +2140,10 @@ int do_epoll_ctl(int epfd, int op, int fd, struct epoll_event *epds,
ep_take_care_of_epollwakeup(epds);
/*
- * We have to check that the file structure underneath the file descriptor
- * the user passed to us _is_ an eventpoll file. And also we do not permit
- * adding an epoll file descriptor inside itself.
+ * We do not permit adding an epoll file descriptor inside itself.
*/
error = -EINVAL;
- if (f.file == tf.file || !is_file_epoll(f.file))
+ if (f.file == tf.file)
goto error_tgt_fput;
/*
@@ -2147,12 +2159,6 @@ int do_epoll_ctl(int epfd, int op, int fd, struct epoll_event *epds,
goto error_tgt_fput;
}
- /*
- * At this point it is safe to assume that the "private_data" contains
- * our own data structure.
- */
- ep = f.file->private_data;
-
/*
* When we insert an epoll file descriptor inside another epoll file
* descriptor, there is the chance of creating closed loops, which are
This just cleans up the checking a bit, in preparation for a change that will need access to 'ep' earlier. Signed-off-by: Jens Axboe <axboe@kernel.dk> --- fs/eventpoll.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-)