From 5ade5fbdbbb1f023bb70730ba4d74146c8bc7eb9 Mon Sep 17 00:00:00 2001 From: Hao Ge Date: Mon, 13 May 2024 13:33:38 +0800 Subject: [PATCH] eventfs: Fix a possible null pointer dereference in eventfs_find_events() commit d4e9a968738bf66d3bb852dd5588d4c7afd6d7f4 upstream. In function eventfs_find_events,there is a potential null pointer that may be caused by calling update_events_attr which will perform some operations on the members of the ei struct when ei is NULL. Hence,When ei->is_freed is set,return NULL directly. Link: https://lore.kernel.org/linux-trace-kernel/20240513053338.63017-1-hao.ge@linux.dev Cc: stable@vger.kernel.org Fixes: 8186fff7ab64 ("tracefs/eventfs: Use root and instance inodes as default ownership") Signed-off-by: Hao Ge Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman --- fs/tracefs/event_inode.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 3b785f4ca95e..94518a039a99 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -345,10 +345,9 @@ static struct eventfs_inode *eventfs_find_events(struct dentry *dentry) * If the ei is being freed, the ownership of the children * doesn't matter. */ - if (ei->is_freed) { - ei = NULL; - break; - } + if (ei->is_freed) + return NULL; + // Walk upwards until you find the events inode } while (!ei->is_events);