From 27423bb05e251020660e092c2f6b78ad2e4cb9a3 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 24 Sep 2020 19:41:58 -0400 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 --- fs/eventpoll.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 333bb8f9ed0e..339453ac834c 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -1453,7 +1453,7 @@ 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) { @@ -1462,8 +1462,9 @@ 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(NULL, name); + take_dentry_name_snapshot(&n, epi->ffd.file->f_path.dentry); + ws = wakeup_source_register(NULL, n.name.name); + release_dentry_name_snapshot(&n); if (!ws) return -ENOMEM;