From b11afd4d48cea41c37e30d8cdeef4824b68243e8 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 13 Oct 2020 16:47:58 +0800 Subject: [PATCH] ep_create_wakeup_source(): dentry name can change under you... commit 3701cb59d892b88d569427586f01491552f377b1 upstream. or get freed, for that matter, if it's a long (separately stored) name. Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman Signed-off-by: Yang Yingliang --- fs/eventpoll.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 59f9d28964ad..cf332e8f6bdf 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -1376,7 +1376,7 @@ static int reverse_path_check(void) static int ep_create_wakeup_source(struct epitem *epi) { - const char *name; + struct name_snapshot n; struct wakeup_source *ws; if (!epi->ep->ws) { @@ -1385,8 +1385,9 @@ static int ep_create_wakeup_source(struct epitem *epi) return -ENOMEM; } - name = epi->ffd.file->f_path.dentry->d_name.name; - ws = wakeup_source_register(name); + take_dentry_name_snapshot(&n, epi->ffd.file->f_path.dentry); + ws = wakeup_source_register(n.name); + release_dentry_name_snapshot(&n); if (!ws) return -ENOMEM; -- GitLab