[RFC PATCH 09/27] reverse_path_check_proc(): don't bother with cookies

Al Viro
2020-10-04T02:41:09Z

We know there's no loops by the time we call it; the
only thing we care about is too deep reverse paths.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/eventpoll.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 3e6f1f97f246..0f540e91aa92 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -1311,7 +1311,7 @@ static int reverse_path_check_proc(struct file *file, int depth)
int error = 0;
struct epitem *epi;

- if (!ep_push_nested(file)) /* limits recursion */
+ if (depth > EP_MAX_NESTS) /* too deep nesting */
return -1;

/* CTL_DEL can remove links here, but that can't increase our count */
@@ -1336,7 +1336,6 @@ static int reverse_path_check_proc(struct file *file, int depth)
}
}
rcu_read_unlock();
- nesting--; /* pop */
return error;
}

--
2.11.0