| Message ID | 20170214154935.GG1850@uranus.lan (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Index: linux-ml.git/fs/eventpoll.c =================================================================== --- linux-ml.git.orig/fs/eventpoll.c +++ linux-ml.git/fs/eventpoll.c @@ -1895,7 +1895,7 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, in * so EPOLLEXCLUSIVE is not allowed for a EPOLL_CTL_MOD operation. * Also, we do not currently supported nested exclusive wakeups. */ - if (epds.events & EPOLLEXCLUSIVE) { + if (ep_op_has_event(op) && (epds.events & EPOLLEXCLUSIVE)) { if (op == EPOLL_CTL_MOD) goto error_tgt_fput; if (op == EPOLL_CTL_ADD && (is_file_epoll(tf.file) ||
In case if epoll_ctl is called with operation EPOLL_CTL_DEL then @epds.events variable allocated on stack may contain random bits which we test then for EPOLLEXCLUSIVE. Since currently the test look like if (epds.events & EPOLLEXCLUSIVE) { if (op == EPOLL_CTL_MOD) goto error_tgt_fput; if (op == EPOLL_CTL_ADD && (is_file_epoll(tf.file) || (epds.events & ~EPOLLEXCLUSIVE_OK_BITS))) goto error_tgt_fput; } Nothing serious will happen even if epds.events has this bit set, still better to be on safe side and make sure that we're to test this bit at all. Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> --- fs/eventpoll.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)